5713 lines
225 KiB
VHDL
5713 lines
225 KiB
VHDL
-- -----------------------------------------------------------------
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--
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-- Copyright 2019 IEEE P1076 WG Authors
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--
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-- See the LICENSE file distributed with this work for copyright and
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-- licensing information and the AUTHORS file.
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--
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-- This file to you under the Apache License, Version 2.0 (the "License").
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-- You may obtain a copy of the License at
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--
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-- http://www.apache.org/licenses/LICENSE-2.0
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--
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-- Unless required by applicable law or agreed to in writing, software
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-- distributed under the License is distributed on an "AS IS" BASIS,
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-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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-- implied. See the License for the specific language governing
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-- permissions and limitations under the License.
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--
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-- Title : Floating-point package (Generic package body)
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-- :
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-- Library : This package shall be compiled into a library
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-- : symbolically named IEEE.
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-- :
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-- Developers: Accellera VHDL-TC and IEEE P1076 Working Group
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-- :
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-- Purpose : This packages defines basic binary floating point
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-- : arithmetic functions
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-- :
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-- Note : This package may be modified to include additional data
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-- : required by tools, but it must in no way change the
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-- : external interfaces or simulation behavior of the
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-- : description. It is permissible to add comments and/or
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-- : attributes to the package declarations, but not to change
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-- : or delete any original lines of the package declaration.
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-- : The package body may be changed only in accordance with
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-- : the terms of Clause 16 of this standard.
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-- :
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-- --------------------------------------------------------------------
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-- $Revision: 1220 $
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-- $Date: 2008-04-10 17:16:09 +0930 (Thu, 10 Apr 2008) $
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-- --------------------------------------------------------------------
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package body float_generic_pkg is
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-- Author David Bishop (dbishop@vhdl.org)
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-----------------------------------------------------------------------------
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-- type declarations
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-----------------------------------------------------------------------------
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-- This deferred constant will tell you if the package body is synthesizable
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-- or implemented as real numbers, set to "true" if synthesizable.
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constant fphdlsynth_or_real : BOOLEAN := true; -- deferred constant
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-- types of boundary conditions
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type boundary_type is (normal, infinity, zero, denormal);
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-- null range array constant
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constant NAFP : UNRESOLVED_float (0 downto 1) := (others => '0');
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constant NSLV : STD_ULOGIC_VECTOR (0 downto 1) := (others => '0');
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-- Special version of "minimum" to do some boundary checking
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function mine (L, R : INTEGER)
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return INTEGER is
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begin -- function minimum
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if (L = INTEGER'low or R = INTEGER'low) then
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report float_generic_pkg'instance_name
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& " Unbounded number passed, was a literal used?"
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severity error;
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return 0;
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end if;
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return minimum (L, R);
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end function mine;
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-- Generates the base number for the exponent normalization offset.
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function gen_expon_base (
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constant exponent_width : NATURAL)
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return SIGNED
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is
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variable result : SIGNED (exponent_width-1 downto 0);
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begin
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result := (others => '1');
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result (exponent_width-1) := '0';
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return result;
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end function gen_expon_base;
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-- Integer version of the "log2" command (contributed by Peter Ashenden)
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function log2 (A : NATURAL) return NATURAL is
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variable quotient : NATURAL;
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variable result : NATURAL := 0;
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begin
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quotient := A / 2;
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while quotient > 0 loop
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quotient := quotient / 2;
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result := result + 1;
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end loop;
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return result;
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end function log2;
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-- Function similar to the ILOGB function in MATH_REAL
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function log2 (A : REAL) return INTEGER is
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variable Y : REAL;
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variable N : INTEGER := 0;
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begin
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if (A = 1.0 or A = 0.0) then
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return 0;
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end if;
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Y := A;
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if(A > 1.0) then
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while Y >= 2.0 loop
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Y := Y / 2.0;
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N := N + 1;
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end loop;
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return N;
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end if;
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-- O < Y < 1
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while Y < 1.0 loop
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Y := Y * 2.0;
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N := N - 1;
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end loop;
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return N;
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end function log2;
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-- purpose: Test the boundary conditions of a Real number
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procedure test_boundary (
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arg : in REAL; -- Input, converted to real
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constant fraction_width : in NATURAL; -- length of FP output fraction
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constant exponent_width : in NATURAL; -- length of FP exponent
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constant denormalize : in BOOLEAN := true; -- Use IEEE extended FP
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variable btype : out boundary_type;
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variable log2i : out INTEGER
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) is
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constant expon_base : SIGNED (exponent_width-1 downto 0) :=
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gen_expon_base(exponent_width); -- exponent offset
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constant exp_min : SIGNED (12 downto 0) :=
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-(resize(expon_base, 13)) + 1; -- Minimum normal exponent
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constant exp_ext_min : SIGNED (12 downto 0) :=
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exp_min - fraction_width; -- Minimum for denormal exponent
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variable log2arg : INTEGER; -- log2 of argument
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begin -- function test_boundary
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-- Check to see if the exponent is big enough
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-- Note that the argument is always an absolute value at this point.
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log2arg := log2(arg);
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if arg = 0.0 then
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btype := zero;
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elsif exponent_width > 11 then -- Exponent for Real is 11 (64 bit)
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btype := normal;
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else
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if log2arg < to_integer(exp_min) then
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if denormalize then
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if log2arg < to_integer(exp_ext_min) then
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btype := zero;
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else
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btype := denormal;
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end if;
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else
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if log2arg < to_integer(exp_min)-1 then
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btype := zero;
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else
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btype := normal; -- Can still represent this number
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end if;
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end if;
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elsif exponent_width < 11 then
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if log2arg > to_integer(expon_base)+1 then
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btype := infinity;
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else
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btype := normal;
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end if;
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else
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btype := normal;
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end if;
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end if;
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log2i := log2arg;
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end procedure test_boundary;
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-- purpose: Rounds depending on the state of the "round_style"
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-- Logic taken from
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-- "What Every Computer Scientist Should Know About Floating Point Arithmetic"
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-- by David Goldberg (1991)
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function check_round (
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fract_in : STD_ULOGIC; -- input fraction
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sign : STD_ULOGIC; -- sign bit
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remainder : UNSIGNED; -- remainder to round from
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sticky : STD_ULOGIC := '0'; -- Sticky bit
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constant round_style : round_type) -- rounding type
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return BOOLEAN
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is
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variable result : BOOLEAN;
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variable or_reduced : STD_ULOGIC;
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begin -- function check_round
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result := false;
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if (remainder'length > 0) then -- if remainder in a null array
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or_reduced := or (remainder & sticky);
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rounding_case : case round_style is
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when round_nearest => -- Round Nearest, default mode
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if remainder(remainder'high) = '1' then -- round
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if (remainder'length > 1) then
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if ((or (remainder(remainder'high-1
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downto remainder'low)) = '1'
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or sticky = '1')
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or fract_in = '1') then
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-- Make the bottom bit zero if possible if we are at 1/2
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result := true;
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end if;
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else
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result := (fract_in = '1' or sticky = '1');
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end if;
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end if;
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when round_inf => -- round up if positive, else truncate.
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if or_reduced = '1' and sign = '0' then
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result := true;
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end if;
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when round_neginf => -- round down if negative, else truncate.
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if or_reduced = '1' and sign = '1' then
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result := true;
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end if;
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when round_zero => -- round toward 0 Truncate
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null;
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end case rounding_case;
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end if;
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return result;
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end function check_round;
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-- purpose: Rounds depending on the state of the "round_style"
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-- unsigned version
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procedure fp_round (
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fract_in : in UNSIGNED; -- input fraction
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expon_in : in SIGNED; -- input exponent
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fract_out : out UNSIGNED; -- output fraction
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expon_out : out SIGNED) is -- output exponent
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begin -- procedure fp_round
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if and (fract_in) = '1' then -- Fraction is all "1"
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expon_out := expon_in + 1;
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fract_out := to_unsigned(0, fract_out'high+1);
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else
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expon_out := expon_in;
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fract_out := fract_in + 1;
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end if;
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end procedure fp_round;
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-- This version of break_number doesn't call "classfp"
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procedure break_number ( -- internal version
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arg : in UNRESOLVED_float;
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fptyp : in valid_fpstate;
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denormalize : in BOOLEAN := true;
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fract : out UNSIGNED;
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expon : out SIGNED) is
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constant fraction_width : NATURAL := -arg'low; -- length of FP output fraction
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constant exponent_width : NATURAL := arg'high; -- length of FP output exponent
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constant expon_base : SIGNED (exponent_width-1 downto 0) :=
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gen_expon_base(exponent_width); -- exponent offset
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variable exp : SIGNED (expon'range);
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begin
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fract (fraction_width-1 downto 0) :=
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UNSIGNED (to_slv(arg(-1 downto -fraction_width)));
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breakcase : case fptyp is
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when pos_zero | neg_zero =>
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fract (fraction_width) := '0';
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exp := -expon_base;
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when pos_denormal | neg_denormal =>
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if denormalize then
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exp := -expon_base;
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fract (fraction_width) := '0';
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else
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exp := -expon_base - 1;
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fract (fraction_width) := '1';
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end if;
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when pos_normal | neg_normal | pos_inf | neg_inf =>
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fract (fraction_width) := '1';
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exp := SIGNED(arg(exponent_width-1 downto 0));
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exp (exponent_width-1) := not exp(exponent_width-1);
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when others =>
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assert no_warning
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report float_generic_pkg'instance_name
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& "BREAK_NUMBER: " &
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"Meta state detected in fp_break_number process"
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severity warning;
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-- complete the case, if a NAN goes in, a NAN comes out.
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exp := (others => '1');
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fract (fraction_width) := '1';
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end case breakcase;
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expon := exp;
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end procedure break_number;
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-- purpose: floating point to UNSIGNED
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-- Used by to_integer, to_unsigned, and to_signed functions
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procedure float_to_unsigned (
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arg : in UNRESOLVED_float; -- floating point input
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variable sign : out STD_ULOGIC; -- sign of output
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variable frac : out UNSIGNED; -- unsigned biased output
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constant denormalize : in BOOLEAN; -- turn on denormalization
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constant bias : in NATURAL; -- bias for fixed point
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constant round_style : in round_type) is -- rounding method
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constant fraction_width : INTEGER := -mine(arg'low, arg'low); -- length of FP output fraction
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constant exponent_width : INTEGER := arg'high; -- length of FP output exponent
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variable fract : UNSIGNED (frac'range); -- internal version of frac
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variable isign : STD_ULOGIC; -- internal version of sign
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variable exp : INTEGER; -- Exponent
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variable expon : SIGNED (exponent_width-1 downto 0); -- Vectorized exp
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-- Base to divide fraction by
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variable frac_shift : UNSIGNED (frac'high+3 downto 0); -- Fraction shifted
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variable shift : INTEGER;
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variable remainder : UNSIGNED (2 downto 0);
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variable round : STD_ULOGIC; -- round BIT
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begin
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isign := to_x01(arg(arg'high));
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-- exponent /= '0', normal floating point
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expon := to_01(SIGNED(arg (exponent_width-1 downto 0)), 'X');
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expon(exponent_width-1) := not expon(exponent_width-1);
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exp := to_integer (expon);
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-- Figure out the fraction
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fract := (others => '0'); -- fill with zero
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fract (fract'high) := '1'; -- Add the "1.0".
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shift := (fract'high-1) - exp;
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if fraction_width > fract'high then -- Can only use size-2 bits
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fract (fract'high-1 downto 0) := UNSIGNED (to_slv (arg(-1 downto
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-fract'high)));
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else -- can use all bits
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fract (fract'high-1 downto fract'high-fraction_width) :=
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UNSIGNED (to_slv (arg(-1 downto -fraction_width)));
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end if;
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frac_shift := fract & "000";
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if shift < 0 then -- Overflow
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fract := (others => '1');
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else
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frac_shift := shift_right (frac_shift, shift);
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fract := frac_shift (frac_shift'high downto 3);
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remainder := frac_shift (2 downto 0);
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-- round (round_zero will bypass this and truncate)
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case round_style is
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when round_nearest =>
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round := remainder(2) and
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(fract (0) or (or (remainder (1 downto 0))));
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when round_inf =>
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round := remainder(2) and not isign;
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when round_neginf =>
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round := remainder(2) and isign;
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when others =>
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round := '0';
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end case;
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if round = '1' then
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fract := fract + 1;
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end if;
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end if;
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frac := fract;
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sign := isign;
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end procedure float_to_unsigned;
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-- purpose: returns a part of a vector, this function is here because
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-- or (fractr (to_integer(shiftx) downto 0));
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-- can't be synthesized in some synthesis tools.
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function smallfract (
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arg : UNSIGNED;
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shift : NATURAL)
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return STD_ULOGIC
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is
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variable orx : STD_ULOGIC;
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begin
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orx := arg(shift);
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for i in arg'range loop
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if i < shift then
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orx := arg(i) or orx;
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end if;
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end loop;
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return orx;
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end function smallfract;
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---------------------------------------------------------------------------
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-- Visible functions
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---------------------------------------------------------------------------
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-- purpose: converts the negative index to a positive one
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-- negative indices are illegal in 1164 and 1076.3
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function to_sulv (
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arg : UNRESOLVED_float) -- fp vector
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return STD_ULOGIC_VECTOR
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is
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variable intermediate_result : UNRESOLVED_float(arg'length-1 downto 0);
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begin -- function to_std_ulogic_vector
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if arg'length < 1 then
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return NSLV;
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end if;
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intermediate_result := arg;
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return STD_ULOGIC_VECTOR (intermediate_result);
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end function to_sulv;
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-- Converts an fp into an SULV
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function to_slv (arg : UNRESOLVED_float) return STD_LOGIC_VECTOR is
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begin
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return to_sulv (arg);
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end function to_slv;
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-- purpose: normalizes a floating point number
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-- This version assumes an "unsigned" input with
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function normalize (
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fract : UNRESOLVED_UNSIGNED; -- fraction, unnormalized
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expon : UNRESOLVED_SIGNED; -- exponent, normalized by -1
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sign : STD_ULOGIC; -- sign BIT
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sticky : STD_ULOGIC := '0'; -- Sticky bit (rounding)
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constant exponent_width : NATURAL := float_exponent_width; -- size of output exponent
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constant fraction_width : NATURAL := float_fraction_width; -- size of output fraction
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constant round_style : round_type := float_round_style; -- rounding option
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constant denormalize : BOOLEAN := float_denormalize; -- Use IEEE extended FP
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constant nguard : NATURAL := float_guard_bits) -- guard bits
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return UNRESOLVED_float
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is
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variable sfract : UNSIGNED (fract'high downto 0); -- shifted fraction
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variable rfract : UNSIGNED (fraction_width-1 downto 0); -- fraction
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variable exp : SIGNED (exponent_width+1 downto 0); -- exponent
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variable rexp : SIGNED (exponent_width+1 downto 0); -- result exponent
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variable rexpon : UNSIGNED (exponent_width-1 downto 0); -- exponent
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variable result : UNRESOLVED_float (exponent_width downto -fraction_width); -- result
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variable shiftr : INTEGER; -- shift amount
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variable stickyx : STD_ULOGIC; -- version of sticky
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constant expon_base : SIGNED (exponent_width-1 downto 0) :=
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gen_expon_base(exponent_width); -- exponent offset
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variable round, zerores, infres : BOOLEAN;
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begin -- function normalize
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zerores := false;
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infres := false;
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round := false;
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shiftr := find_leftmost (to_01(fract), '1') -- Find the first "1"
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- fraction_width - nguard; -- subtract the length we want
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exp := resize (expon, exp'length) + shiftr;
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if (or (fract) = '0') then -- Zero
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zerores := true;
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elsif ((exp <= -resize(expon_base, exp'length)-1) and denormalize)
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or ((exp < -resize(expon_base, exp'length)-1) and not denormalize) then
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if (exp >= -resize(expon_base, exp'length)-fraction_width-1)
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and denormalize then
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exp := -resize(expon_base, exp'length)-1;
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shiftr := -to_integer (expon + expon_base); -- new shift
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else -- return zero
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zerores := true;
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end if;
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elsif (exp > expon_base-1) then -- infinity
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infres := true;
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end if;
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if zerores then
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result := zerofp (fraction_width => fraction_width,
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exponent_width => exponent_width);
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elsif infres then
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result := pos_inffp (fraction_width => fraction_width,
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exponent_width => exponent_width);
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else
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sfract := fract srl shiftr; -- shift
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if shiftr > 0 then
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-- stickyx := sticky or (or (fract (shiftr-1 downto 0)));
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stickyx := sticky or smallfract (fract, shiftr-1);
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else
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stickyx := sticky;
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end if;
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if nguard > 0 then
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round := check_round (
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fract_in => sfract (nguard),
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sign => sign,
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remainder => sfract(nguard-1 downto 0),
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sticky => stickyx,
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round_style => round_style);
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end if;
|
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if round then
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fp_round(fract_in => sfract (fraction_width-1+nguard downto nguard),
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expon_in => exp(rexp'range),
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fract_out => rfract,
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expon_out => rexp);
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else
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rfract := sfract (fraction_width-1+nguard downto nguard);
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rexp := exp(rexp'range);
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end if;
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-- result
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rexpon := UNSIGNED (rexp(exponent_width-1 downto 0));
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rexpon (exponent_width-1) := not rexpon(exponent_width-1);
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result (rexpon'range) := UNRESOLVED_float(rexpon);
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result (-1 downto -fraction_width) := UNRESOLVED_float(rfract);
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end if;
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result (exponent_width) := sign; -- sign BIT
|
|
return result;
|
|
end function normalize;
|
|
|
|
-- purpose: normalizes a floating point number
|
|
-- This version assumes a "ufixed" input
|
|
function normalize (
|
|
fract : UNRESOLVED_ufixed; -- unsigned fixed point
|
|
expon : UNRESOLVED_SIGNED; -- exponent, normalized by -1
|
|
sign : STD_ULOGIC; -- sign bit
|
|
sticky : STD_ULOGIC := '0'; -- Sticky bit (rounding)
|
|
constant exponent_width : NATURAL := float_exponent_width; -- size of output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- size of output fraction
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant denormalize : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant nguard : NATURAL := float_guard_bits) -- guard bits
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable arguns : UNSIGNED (fract'high + fraction_width + nguard
|
|
downto 0) := (others => '0');
|
|
begin -- function normalize
|
|
arguns (arguns'high downto maximum (arguns'high-fract'length+1, 0)) :=
|
|
UNSIGNED (to_slv (fract));
|
|
result := normalize (fract => arguns,
|
|
expon => expon,
|
|
sign => sign,
|
|
sticky => sticky,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => nguard);
|
|
return result;
|
|
end function normalize;
|
|
|
|
-- purpose: normalizes a floating point number
|
|
-- This version assumes a "ufixed" input with a "size_res" input
|
|
function normalize (
|
|
fract : UNRESOLVED_ufixed; -- unsigned fixed point
|
|
expon : UNRESOLVED_SIGNED; -- exponent, normalized by -1
|
|
sign : STD_ULOGIC; -- sign bit
|
|
sticky : STD_ULOGIC := '0'; -- Sticky bit (rounding)
|
|
size_res : UNRESOLVED_float; -- used for sizing only
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant denormalize : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant nguard : NATURAL := float_guard_bits) -- guard bits
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -size_res'low;
|
|
constant exponent_width : NATURAL := size_res'high;
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable arguns : UNSIGNED (fract'high + fraction_width + nguard
|
|
downto 0) := (others => '0');
|
|
begin -- function normalize
|
|
arguns (arguns'high downto maximum (arguns'high-fract'length+1, 0)) :=
|
|
UNSIGNED (to_slv (fract));
|
|
result := normalize (fract => arguns,
|
|
expon => expon,
|
|
sign => sign,
|
|
sticky => sticky,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => nguard);
|
|
return result;
|
|
end function normalize;
|
|
|
|
-- Regular "normalize" function with a "size_res" input.
|
|
function normalize (
|
|
fract : UNRESOLVED_UNSIGNED; -- unsigned
|
|
expon : UNRESOLVED_SIGNED; -- exponent - 1, normalized
|
|
sign : STD_ULOGIC; -- sign bit
|
|
sticky : STD_ULOGIC := '0'; -- Sticky bit (rounding)
|
|
size_res : UNRESOLVED_float; -- used for sizing only
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant denormalize : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant nguard : NATURAL := float_guard_bits) -- guard bits
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return normalize (fract => fract,
|
|
expon => expon,
|
|
sign => sign,
|
|
sticky => sticky,
|
|
fraction_width => -size_res'low,
|
|
exponent_width => size_res'high,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => nguard);
|
|
end function normalize;
|
|
|
|
-- Returns the class which X falls into
|
|
function Classfp (
|
|
x : UNRESOLVED_float; -- floating point input
|
|
check_error : BOOLEAN := float_check_error) -- check for errors
|
|
return valid_fpstate
|
|
is
|
|
constant fraction_width : INTEGER := -mine(x'low, x'low); -- length of FP output fraction
|
|
constant exponent_width : INTEGER := x'high; -- length of FP output exponent
|
|
variable arg : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- classfp
|
|
if (arg'length < 1 or fraction_width < 3 or exponent_width < 3
|
|
or x'left < x'right) then
|
|
report float_generic_pkg'instance_name
|
|
& "CLASSFP: " &
|
|
"Floating point number detected with a bad range"
|
|
severity error;
|
|
return isx;
|
|
end if;
|
|
-- Check for "X".
|
|
arg := to_01 (x, 'X');
|
|
if (arg(0) = 'X') then
|
|
return isx; -- If there is an X in the number
|
|
-- Special cases, check for illegal number
|
|
elsif check_error and
|
|
(and (STD_ULOGIC_VECTOR (arg (exponent_width-1 downto 0)))
|
|
= '1') then -- Exponent is all "1".
|
|
if or (to_slv (arg (-1 downto -fraction_width)))
|
|
/= '0' then -- Fraction must be all "0" or this is not a number.
|
|
if (arg(-1) = '1') then -- From "W. Khan - IEEE standard
|
|
return nan; -- 754 binary FP Signaling nan (Not a number)
|
|
else
|
|
return quiet_nan;
|
|
end if;
|
|
-- Check for infinity
|
|
elsif arg(exponent_width) = '0' then
|
|
return pos_inf; -- Positive infinity
|
|
else
|
|
return neg_inf; -- Negative infinity
|
|
end if;
|
|
-- check for "0"
|
|
elsif or (STD_LOGIC_VECTOR (arg (exponent_width-1 downto 0)))
|
|
= '0' then -- Exponent is all "0"
|
|
if or (to_slv (arg (-1 downto -fraction_width)))
|
|
= '0' then -- Fraction is all "0"
|
|
if arg(exponent_width) = '0' then
|
|
return pos_zero; -- Zero
|
|
else
|
|
return neg_zero;
|
|
end if;
|
|
else
|
|
if arg(exponent_width) = '0' then
|
|
return pos_denormal; -- Denormal number (ieee extended fp)
|
|
else
|
|
return neg_denormal;
|
|
end if;
|
|
end if;
|
|
else
|
|
if arg(exponent_width) = '0' then
|
|
return pos_normal; -- Normal FP number
|
|
else
|
|
return neg_normal;
|
|
end if;
|
|
end if;
|
|
end function Classfp;
|
|
|
|
procedure break_number (
|
|
arg : in UNRESOLVED_float;
|
|
denormalize : in BOOLEAN := float_denormalize;
|
|
check_error : in BOOLEAN := float_check_error;
|
|
fract : out UNRESOLVED_UNSIGNED;
|
|
expon : out UNRESOLVED_SIGNED;
|
|
sign : out STD_ULOGIC) is
|
|
variable fptyp : valid_fpstate;
|
|
begin
|
|
fptyp := Classfp (arg, check_error);
|
|
sign := to_x01(arg(arg'high));
|
|
break_number (
|
|
arg => arg,
|
|
fptyp => fptyp,
|
|
denormalize => denormalize,
|
|
fract => fract,
|
|
expon => expon);
|
|
end procedure break_number;
|
|
|
|
procedure break_number (
|
|
arg : in UNRESOLVED_float;
|
|
denormalize : in BOOLEAN := float_denormalize;
|
|
check_error : in BOOLEAN := float_check_error;
|
|
fract : out UNRESOLVED_ufixed; -- 1 downto -fraction_width
|
|
expon : out UNRESOLVED_SIGNED; -- exponent_width-1 downto 0
|
|
sign : out STD_ULOGIC) is
|
|
constant fraction_width : NATURAL := -mine(arg'low, arg'low); -- length of FP output fraction
|
|
variable fptyp : valid_fpstate;
|
|
variable ufract : UNSIGNED (fraction_width downto 0); -- unsigned fraction
|
|
begin
|
|
fptyp := Classfp (arg, check_error);
|
|
sign := to_x01(arg(arg'high));
|
|
break_number (
|
|
arg => arg,
|
|
fptyp => fptyp,
|
|
denormalize => denormalize,
|
|
fract => ufract,
|
|
expon => expon);
|
|
fract (0 downto -fraction_width) := ufixed (ufract);
|
|
end procedure break_number;
|
|
|
|
-- Arithmetic functions
|
|
function "abs" (
|
|
arg : UNRESOLVED_float) -- floating point input
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (arg'range); -- result
|
|
begin
|
|
if (arg'length > 0) then
|
|
result := to_01 (arg, 'X');
|
|
result (arg'high) := '0'; -- set the sign bit to positive
|
|
return result;
|
|
else
|
|
return NAFP;
|
|
end if;
|
|
end function "abs";
|
|
|
|
-- IEEE 754 "negative" function
|
|
function "-" (
|
|
arg : UNRESOLVED_float) -- floating point input
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (arg'range); -- result
|
|
begin
|
|
if (arg'length > 0) then
|
|
result := to_01 (arg, 'X');
|
|
result (arg'high) := not result (arg'high); -- invert sign bit
|
|
return result;
|
|
else
|
|
return NAFP;
|
|
end if;
|
|
end function "-";
|
|
|
|
-- Addition, adds two floating point numbers
|
|
function add (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
constant addguard : NATURAL := guard; -- add one guard bit
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable fractl, fractr : UNSIGNED (fraction_width+1+addguard downto 0); -- fractions
|
|
variable fractc, fracts : UNSIGNED (fractl'range); -- constant and shifted variables
|
|
variable urfract, ulfract : UNSIGNED (fraction_width downto 0);
|
|
variable ufract : UNSIGNED (fraction_width+1+addguard downto 0);
|
|
variable exponl, exponr : SIGNED (exponent_width-1 downto 0); -- exponents
|
|
variable rexpon : SIGNED (exponent_width downto 0); -- result exponent
|
|
variable shiftx : SIGNED (exponent_width downto 0); -- shift fractions
|
|
variable sign : STD_ULOGIC; -- sign of the output
|
|
variable leftright : BOOLEAN; -- left or right used
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable sticky : STD_ULOGIC; -- Holds precision for rounding
|
|
begin -- addition
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
if (lfptype = isx or rfptype = isx) then
|
|
fpresult := (others => 'X');
|
|
elsif (lfptype = nan or lfptype = quiet_nan or
|
|
rfptype = nan or rfptype = quiet_nan)
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
or (lfptype = pos_inf and rfptype = neg_inf)
|
|
or (lfptype = neg_inf and rfptype = pos_inf) then
|
|
-- Return quiet NAN, IEEE754-1985-7.1,2
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (lfptype = pos_inf or rfptype = pos_inf) then -- x + inf = inf
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (lfptype = neg_inf or rfptype = neg_inf) then -- x - inf = -inf
|
|
fpresult := neg_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (lfptype = neg_zero and rfptype = neg_zero) then -- -0 + -0 = -0
|
|
fpresult := neg_zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
lfptype := Classfp (lresize, false); -- errors already checked
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rfptype := Classfp (rresize, false); -- errors already checked
|
|
break_number (
|
|
arg => lresize,
|
|
fptyp => lfptype,
|
|
denormalize => denormalize,
|
|
fract => ulfract,
|
|
expon => exponl);
|
|
fractl := (others => '0');
|
|
fractl (fraction_width+addguard downto addguard) := ulfract;
|
|
break_number (
|
|
arg => rresize,
|
|
fptyp => rfptype,
|
|
denormalize => denormalize,
|
|
fract => urfract,
|
|
expon => exponr);
|
|
fractr := (others => '0');
|
|
fractr (fraction_width+addguard downto addguard) := urfract;
|
|
shiftx := (exponl(exponent_width-1) & exponl) - exponr;
|
|
if shiftx < -fractl'high then
|
|
rexpon := exponr(exponent_width-1) & exponr;
|
|
fractc := fractr;
|
|
fracts := (others => '0'); -- add zero
|
|
leftright := false;
|
|
sticky := or (fractl);
|
|
elsif shiftx < 0 then
|
|
shiftx := - shiftx;
|
|
fracts := shift_right (fractl, to_integer(shiftx));
|
|
fractc := fractr;
|
|
rexpon := exponr(exponent_width-1) & exponr;
|
|
leftright := false;
|
|
-- sticky := or (fractl (to_integer(shiftx) downto 0));
|
|
sticky := smallfract (fractl, to_integer(shiftx));
|
|
elsif shiftx = 0 then
|
|
rexpon := exponl(exponent_width-1) & exponl;
|
|
sticky := '0';
|
|
if fractr > fractl then
|
|
fractc := fractr;
|
|
fracts := fractl;
|
|
leftright := false;
|
|
else
|
|
fractc := fractl;
|
|
fracts := fractr;
|
|
leftright := true;
|
|
end if;
|
|
elsif shiftx > fractr'high then
|
|
rexpon := exponl(exponent_width-1) & exponl;
|
|
fracts := (others => '0'); -- add zero
|
|
fractc := fractl;
|
|
leftright := true;
|
|
sticky := or (fractr);
|
|
elsif shiftx > 0 then
|
|
fracts := shift_right (fractr, to_integer(shiftx));
|
|
fractc := fractl;
|
|
rexpon := exponl(exponent_width-1) & exponl;
|
|
leftright := true;
|
|
-- sticky := or (fractr (to_integer(shiftx) downto 0));
|
|
sticky := smallfract (fractr, to_integer(shiftx));
|
|
end if;
|
|
-- add
|
|
fracts (0) := fracts (0) or sticky; -- Or the sticky bit into the LSB
|
|
if l(l'high) = r(r'high) then
|
|
ufract := fractc + fracts;
|
|
sign := l(l'high);
|
|
else -- signs are different
|
|
ufract := fractc - fracts; -- always positive result
|
|
if leftright then -- Figure out which sign to use
|
|
sign := l(l'high);
|
|
else
|
|
sign := r(r'high);
|
|
end if;
|
|
end if;
|
|
if or (ufract) = '0' then
|
|
sign := '0'; -- IEEE 854, 6.3, paragraph 2.
|
|
end if;
|
|
-- normalize
|
|
fpresult := normalize (fract => ufract,
|
|
expon => rexpon,
|
|
sign => sign,
|
|
sticky => sticky,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => addguard);
|
|
end if;
|
|
return fpresult;
|
|
end function add;
|
|
|
|
-- Subtraction, Calls "add".
|
|
function subtract (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
variable negr : UNRESOLVED_float (r'range); -- negative version of r
|
|
begin
|
|
negr := -r; -- r := -r
|
|
return add (l => l,
|
|
r => negr,
|
|
round_style => round_style,
|
|
guard => guard,
|
|
check_error => check_error,
|
|
denormalize => denormalize);
|
|
end function subtract;
|
|
|
|
-- Floating point multiply
|
|
function multiply (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
constant multguard : NATURAL := guard; -- guard bits
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable fractl, fractr : UNSIGNED (fraction_width downto 0); -- fractions
|
|
variable rfract : UNSIGNED ((2*(fraction_width))+1 downto 0); -- result fraction
|
|
variable sfract : UNSIGNED (fraction_width+1+multguard downto 0); -- result fraction
|
|
variable shifty : INTEGER; -- denormal shift
|
|
variable exponl, exponr : SIGNED (exponent_width-1 downto 0); -- exponents
|
|
variable rexpon : SIGNED (exponent_width+1 downto 0); -- result exponent
|
|
variable fp_sign : STD_ULOGIC; -- sign of result
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable sticky : STD_ULOGIC; -- Holds precision for rounding
|
|
begin -- multiply
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
if (lfptype = isx or rfptype = isx) then
|
|
fpresult := (others => 'X');
|
|
elsif ((lfptype = nan or lfptype = quiet_nan or
|
|
rfptype = nan or rfptype = quiet_nan)) then
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (((lfptype = pos_inf or lfptype = neg_inf) and
|
|
(rfptype = pos_zero or rfptype = neg_zero)) or
|
|
((rfptype = pos_inf or rfptype = neg_inf) and
|
|
(lfptype = pos_zero or lfptype = neg_zero))) then -- 0 * inf
|
|
-- Return quiet NAN, IEEE754-1985-7.1,3
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (lfptype = pos_inf or rfptype = pos_inf
|
|
or lfptype = neg_inf or rfptype = neg_inf) then -- x * inf = inf
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
-- figure out the sign
|
|
fp_sign := l(l'high) xor r(r'high); -- figure out the sign
|
|
fpresult (exponent_width) := fp_sign;
|
|
else
|
|
fp_sign := l(l'high) xor r(r'high); -- figure out the sign
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
lfptype := Classfp (lresize, false); -- errors already checked
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rfptype := Classfp (rresize, false); -- errors already checked
|
|
break_number (
|
|
arg => lresize,
|
|
fptyp => lfptype,
|
|
denormalize => denormalize,
|
|
fract => fractl,
|
|
expon => exponl);
|
|
break_number (
|
|
arg => rresize,
|
|
fptyp => rfptype,
|
|
denormalize => denormalize,
|
|
fract => fractr,
|
|
expon => exponr);
|
|
if (rfptype = pos_denormal or rfptype = neg_denormal) then
|
|
shifty := fraction_width - find_leftmost(fractr, '1');
|
|
fractr := shift_left (fractr, shifty);
|
|
elsif (lfptype = pos_denormal or lfptype = neg_denormal) then
|
|
shifty := fraction_width - find_leftmost(fractl, '1');
|
|
fractl := shift_left (fractl, shifty);
|
|
else
|
|
shifty := 0;
|
|
-- Note that a denormal number * a denormal number is always zero.
|
|
end if;
|
|
-- multiply
|
|
-- add the exponents
|
|
rexpon := resize (exponl, rexpon'length) + exponr - shifty + 1;
|
|
rfract := fractl * fractr; -- Multiply the fraction
|
|
sfract := rfract (rfract'high downto
|
|
rfract'high - (fraction_width+1+multguard));
|
|
sticky := or (rfract (rfract'high-(fraction_width+1+multguard)
|
|
downto 0));
|
|
-- normalize
|
|
fpresult := normalize (fract => sfract,
|
|
expon => rexpon,
|
|
sign => fp_sign,
|
|
sticky => sticky,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => multguard);
|
|
end if;
|
|
return fpresult;
|
|
end function multiply;
|
|
|
|
function short_divide (
|
|
lx, rx : UNSIGNED)
|
|
return UNSIGNED
|
|
is
|
|
-- This is a special divider for the floating point routines.
|
|
-- For a true unsigned divider, "stages" needs to = lx'high
|
|
constant stages : INTEGER := lx'high - rx'high; -- number of stages
|
|
variable partial : UNSIGNED (lx'range);
|
|
variable q : UNSIGNED (stages downto 0);
|
|
variable partial_argl : SIGNED (rx'high + 2 downto 0);
|
|
variable partial_arg : SIGNED (rx'high + 2 downto 0);
|
|
begin
|
|
partial := lx;
|
|
for i in stages downto 0 loop
|
|
partial_argl := resize ("0" & SIGNED (partial(lx'high downto i)),
|
|
partial_argl'length);
|
|
partial_arg := partial_argl - SIGNED ("0" & rx);
|
|
if (partial_arg (partial_arg'high) = '1') then -- negative
|
|
q(i) := '0';
|
|
else
|
|
q(i) := '1';
|
|
partial (lx'high+i-stages downto lx'high+i-stages-rx'high) :=
|
|
UNSIGNED (partial_arg(rx'range));
|
|
end if;
|
|
end loop;
|
|
-- to make the output look like that of the unsigned IEEE divide.
|
|
return resize (q, lx'length);
|
|
end function short_divide;
|
|
|
|
-- 1/X function. Needed for algorithm development.
|
|
function reciprocal (
|
|
arg : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(arg'low, arg'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := arg'high; -- length of FP output exponent
|
|
constant divguard : NATURAL := guard; -- guard bits
|
|
function onedivy (
|
|
arg : UNSIGNED)
|
|
return UNSIGNED
|
|
is
|
|
variable q : UNSIGNED((2*arg'high)+1 downto 0);
|
|
variable one : UNSIGNED (q'range);
|
|
begin
|
|
one := (others => '0');
|
|
one(one'high) := '1';
|
|
q := short_divide (one, arg); -- Unsigned divide
|
|
return resize (q, arg'length+1);
|
|
end function onedivy;
|
|
variable fptype : valid_fpstate;
|
|
variable expon : SIGNED (exponent_width-1 downto 0); -- exponents
|
|
variable denorm_offset : NATURAL range 0 to 2;
|
|
variable fract : UNSIGNED (fraction_width downto 0);
|
|
variable fractg : UNSIGNED (fraction_width+divguard downto 0);
|
|
variable sfract : UNSIGNED (fraction_width+1+divguard downto 0); -- result fraction
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- reciprocal
|
|
fptype := Classfp(arg, check_error);
|
|
classcase : case fptype is
|
|
when isx =>
|
|
fpresult := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_inf | neg_inf => -- 1/inf, return 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when neg_zero | pos_zero => -- 1/0
|
|
report float_generic_pkg'instance_name
|
|
& "RECIPROCAL: Floating Point divide by zero"
|
|
severity error;
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when others =>
|
|
if (fptype = pos_denormal or fptype = neg_denormal)
|
|
and ((arg (-1) or arg(-2)) /= '1') then
|
|
-- 1/denormal = infinity, with the exception of 2**-expon_base
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fpresult (exponent_width) := to_x01 (arg (exponent_width));
|
|
else
|
|
break_number (
|
|
arg => arg,
|
|
fptyp => fptype,
|
|
denormalize => denormalize,
|
|
fract => fract,
|
|
expon => expon);
|
|
fractg := (others => '0');
|
|
if (fptype = pos_denormal or fptype = neg_denormal) then
|
|
-- The reciprocal of a denormal number is typically zero,
|
|
-- except for two special cases which are trapped here.
|
|
if (to_x01(arg (-1)) = '1') then
|
|
fractg (fractg'high downto divguard+1) :=
|
|
fract (fract'high-1 downto 0); -- Shift to not denormal
|
|
denorm_offset := 1; -- add 1 to exponent compensate
|
|
else -- arg(-2) = '1'
|
|
fractg (fractg'high downto divguard+2) :=
|
|
fract (fract'high-2 downto 0); -- Shift to not denormal
|
|
denorm_offset := 2; -- add 2 to exponent compensate
|
|
end if;
|
|
else
|
|
fractg (fractg'high downto divguard) := fract;
|
|
denorm_offset := 0;
|
|
end if;
|
|
expon := - expon - 3 + denorm_offset;
|
|
sfract := onedivy (fractg);
|
|
-- normalize
|
|
fpresult := normalize (fract => sfract,
|
|
expon => expon,
|
|
sign => arg(exponent_width),
|
|
sticky => '1',
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => divguard);
|
|
end if;
|
|
end case classcase;
|
|
return fpresult;
|
|
end function reciprocal;
|
|
|
|
-- floating point division
|
|
function divide (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
constant divguard : NATURAL := guard; -- division guard bits
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable ulfract, urfract : UNSIGNED (fraction_width downto 0);
|
|
variable fractl : UNSIGNED ((2*(fraction_width+divguard)+1) downto 0); -- left
|
|
variable fractr : UNSIGNED (fraction_width+divguard downto 0); -- right
|
|
variable rfract : UNSIGNED (fractl'range); -- result fraction
|
|
variable sfract : UNSIGNED (fraction_width+1+divguard downto 0); -- result fraction
|
|
variable exponl, exponr : SIGNED (exponent_width-1 downto 0); -- exponents
|
|
variable rexpon : SIGNED (exponent_width+1 downto 0); -- result exponent
|
|
variable fp_sign, sticky : STD_ULOGIC; -- sign of result
|
|
variable shifty, shiftx : INTEGER; -- denormal number shift
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- divide
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
classcase : case rfptype is
|
|
when isx =>
|
|
fpresult := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_inf | neg_inf =>
|
|
if lfptype = pos_inf or lfptype = neg_inf -- inf / inf
|
|
or lfptype = quiet_nan or lfptype = nan then
|
|
-- Return quiet NAN, IEEE754-1985-7.1,4
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else -- x / inf = 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult (fpresult'high) := fp_sign; -- sign
|
|
end if;
|
|
when pos_zero | neg_zero =>
|
|
if lfptype = pos_zero or lfptype = neg_zero -- 0 / 0
|
|
or lfptype = quiet_nan or lfptype = nan then
|
|
-- Return quiet NAN, IEEE754-1985-7.1,4
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
report float_generic_pkg'instance_name
|
|
& "DIVIDE: Floating Point divide by zero"
|
|
severity error;
|
|
-- Infinity, define in 754-1985-7.2
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult (fpresult'high) := fp_sign; -- sign
|
|
end if;
|
|
when others =>
|
|
classcase2 : case lfptype is
|
|
when isx =>
|
|
fpresult := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_inf | neg_inf => -- inf / x = inf
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult(exponent_width) := fp_sign;
|
|
when pos_zero | neg_zero => -- 0 / X = 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult(exponent_width) := fp_sign;
|
|
when others =>
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
lfptype := Classfp (lresize, false); -- errors already checked
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rfptype := Classfp (rresize, false); -- errors already checked
|
|
break_number (
|
|
arg => lresize,
|
|
fptyp => lfptype,
|
|
denormalize => denormalize,
|
|
fract => ulfract,
|
|
expon => exponl);
|
|
-- right side
|
|
break_number (
|
|
arg => rresize,
|
|
fptyp => rfptype,
|
|
denormalize => denormalize,
|
|
fract => urfract,
|
|
expon => exponr);
|
|
-- Compute the exponent
|
|
rexpon := resize (exponl, rexpon'length) - exponr - 2;
|
|
if (rfptype = pos_denormal or rfptype = neg_denormal) then
|
|
-- Do the shifting here not after. That way we have a smaller
|
|
-- shifter, and need a smaller divider, because the top
|
|
-- bit in the divisor will always be a "1".
|
|
shifty := fraction_width - find_leftmost(urfract, '1');
|
|
urfract := shift_left (urfract, shifty);
|
|
rexpon := rexpon + shifty;
|
|
end if;
|
|
fractr := (others => '0');
|
|
fractr (fraction_width+divguard downto divguard) := urfract;
|
|
if (lfptype = pos_denormal or lfptype = neg_denormal) then
|
|
shiftx := fraction_width - find_leftmost(ulfract, '1');
|
|
ulfract := shift_left (ulfract, shiftx);
|
|
rexpon := rexpon - shiftx;
|
|
end if;
|
|
fractl := (others => '0');
|
|
fractl (fractl'high downto fractl'high-fraction_width) := ulfract;
|
|
-- divide
|
|
rfract := short_divide (fractl, fractr); -- unsigned divide
|
|
sfract := rfract (sfract'range); -- lower bits
|
|
sticky := '1';
|
|
-- normalize
|
|
fpresult := normalize (fract => sfract,
|
|
expon => rexpon,
|
|
sign => fp_sign,
|
|
sticky => sticky,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => divguard);
|
|
end case classcase2;
|
|
end case classcase;
|
|
return fpresult;
|
|
end function divide;
|
|
|
|
-- division by a power of 2
|
|
function dividebyp2 (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable ulfract, urfract : UNSIGNED (fraction_width downto 0);
|
|
variable exponl, exponr : SIGNED(exponent_width-1 downto 0); -- exponents
|
|
variable rexpon : SIGNED(exponent_width downto 0); -- result exponent
|
|
variable fp_sign : STD_ULOGIC; -- sign of result
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- divisionbyp2
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
classcase : case rfptype is
|
|
when isx =>
|
|
fpresult := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_inf | neg_inf =>
|
|
if lfptype = pos_inf or lfptype = neg_inf then -- inf / inf
|
|
-- Return quiet NAN, IEEE754-1985-7.1,4
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else -- x / inf = 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult (fpresult'high) := fp_sign; -- sign
|
|
end if;
|
|
when pos_zero | neg_zero =>
|
|
if lfptype = pos_zero or lfptype = neg_zero then -- 0 / 0
|
|
-- Return quiet NAN, IEEE754-1985-7.1,4
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
report float_generic_pkg'instance_name
|
|
& "DIVIDEBYP2: Floating Point divide by zero"
|
|
severity error;
|
|
-- Infinity, define in 754-1985-7.2
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult (fpresult'high) := fp_sign; -- sign
|
|
end if;
|
|
when others =>
|
|
classcase2 : case lfptype is
|
|
when isx =>
|
|
fpresult := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_inf | neg_inf => -- inf / x = inf
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult (exponent_width) := fp_sign; -- sign
|
|
when pos_zero | neg_zero => -- 0 / X = 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
fpresult (exponent_width) := fp_sign; -- sign
|
|
when others =>
|
|
fp_sign := l(l'high) xor r(r'high); -- sign
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
lfptype := Classfp (lresize, false); -- errors already checked
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rfptype := Classfp (rresize, false); -- errors already checked
|
|
break_number (
|
|
arg => lresize,
|
|
fptyp => lfptype,
|
|
denormalize => denormalize,
|
|
fract => ulfract,
|
|
expon => exponl);
|
|
-- right side
|
|
break_number (
|
|
arg => rresize,
|
|
fptyp => rfptype,
|
|
denormalize => denormalize,
|
|
fract => urfract,
|
|
expon => exponr);
|
|
assert (or (urfract (fraction_width-1 downto 0)) = '0')
|
|
report float_generic_pkg'instance_name
|
|
& "DIVIDEBYP2: "
|
|
& "Dividebyp2 called with a non power of two divisor"
|
|
severity error;
|
|
rexpon := (exponl(exponl'high)&exponl)
|
|
- (exponr(exponr'high)&exponr) - 1;
|
|
-- normalize
|
|
fpresult := normalize (fract => ulfract,
|
|
expon => rexpon,
|
|
sign => fp_sign,
|
|
sticky => '1',
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => 0);
|
|
end case classcase2;
|
|
end case classcase;
|
|
return fpresult;
|
|
end function dividebyp2;
|
|
|
|
-- Multiply accumulate result = l*r + c
|
|
function mac (
|
|
l, r, c : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL :=
|
|
-mine (mine(l'low, r'low), c'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL :=
|
|
maximum (maximum(l'high, r'high), c'high); -- length of FP output exponent
|
|
variable lfptype, rfptype, cfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable fractl, fractr : UNSIGNED (fraction_width downto 0); -- fractions
|
|
variable fractx : UNSIGNED (fraction_width+guard downto 0);
|
|
variable fractc, fracts : UNSIGNED (fraction_width+1+guard downto 0);
|
|
variable rfract : UNSIGNED ((2*(fraction_width))+1 downto 0); -- result fraction
|
|
variable ufract : UNSIGNED (fraction_width+1+guard downto 0); -- result fraction
|
|
variable exponl, exponr, exponc : SIGNED (exponent_width-1 downto 0); -- exponents
|
|
variable rexpon, rexpon2 : SIGNED (exponent_width+1 downto 0); -- result exponent
|
|
variable shifty : INTEGER; -- denormal shift
|
|
variable shiftx : SIGNED (rexpon'range); -- shift fractions
|
|
variable fp_sign : STD_ULOGIC; -- sign of result
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable cresize : UNRESOLVED_float (exponent_width downto -fraction_width - guard);
|
|
variable leftright : BOOLEAN; -- left or right used
|
|
variable sticky : STD_ULOGIC; -- Holds precision for rounding
|
|
begin -- multiply
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7 or c'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
cfptype := Classfp (c, check_error);
|
|
end if;
|
|
if (lfptype = isx or rfptype = isx or cfptype = isx) then
|
|
fpresult := (others => 'X');
|
|
elsif (lfptype = nan or lfptype = quiet_nan or
|
|
rfptype = nan or rfptype = quiet_nan or
|
|
cfptype = nan or cfptype = quiet_nan) then
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (((lfptype = pos_inf or lfptype = neg_inf) and
|
|
(rfptype = pos_zero or rfptype = neg_zero)) or
|
|
((rfptype = pos_inf or rfptype = neg_inf) and
|
|
(lfptype = pos_zero or lfptype = neg_zero))) then -- 0 * inf
|
|
-- Return quiet NAN, IEEE754-1985-7.1,3
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (lfptype = pos_inf or rfptype = pos_inf
|
|
or lfptype = neg_inf or rfptype = neg_inf -- x * inf = inf
|
|
or cfptype = neg_inf or cfptype = pos_inf) then -- x + inf = inf
|
|
fpresult := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
-- figure out the sign
|
|
fpresult (exponent_width) := l(l'high) xor r(r'high);
|
|
else
|
|
fp_sign := l(l'high) xor r(r'high); -- figure out the sign
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
lfptype := Classfp (lresize, false); -- errors already checked
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rfptype := Classfp (rresize, false); -- errors already checked
|
|
cresize := resize (arg => to_X01(c),
|
|
exponent_width => exponent_width,
|
|
fraction_width => -cresize'low,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
cfptype := Classfp (cresize, false); -- errors already checked
|
|
break_number (
|
|
arg => lresize,
|
|
fptyp => lfptype,
|
|
denormalize => denormalize,
|
|
fract => fractl,
|
|
expon => exponl);
|
|
break_number (
|
|
arg => rresize,
|
|
fptyp => rfptype,
|
|
denormalize => denormalize,
|
|
fract => fractr,
|
|
expon => exponr);
|
|
break_number (
|
|
arg => cresize,
|
|
fptyp => cfptype,
|
|
denormalize => denormalize,
|
|
fract => fractx,
|
|
expon => exponc);
|
|
if (rfptype = pos_denormal or rfptype = neg_denormal) then
|
|
shifty := fraction_width - find_leftmost(fractr, '1');
|
|
fractr := shift_left (fractr, shifty);
|
|
elsif (lfptype = pos_denormal or lfptype = neg_denormal) then
|
|
shifty := fraction_width - find_leftmost(fractl, '1');
|
|
fractl := shift_left (fractl, shifty);
|
|
else
|
|
shifty := 0;
|
|
-- Note that a denormal number * a denormal number is always zero.
|
|
end if;
|
|
-- multiply
|
|
rfract := fractl * fractr; -- Multiply the fraction
|
|
-- add the exponents
|
|
rexpon := resize (exponl, rexpon'length) + exponr - shifty + 1;
|
|
shiftx := rexpon - exponc;
|
|
if shiftx < -fractl'high then
|
|
rexpon2 := resize (exponc, rexpon2'length);
|
|
fractc := "0" & fractx;
|
|
fracts := (others => '0');
|
|
sticky := or (rfract);
|
|
elsif shiftx < 0 then
|
|
shiftx := - shiftx;
|
|
fracts := shift_right (rfract (rfract'high downto rfract'high
|
|
- fracts'length+1),
|
|
to_integer(shiftx));
|
|
fractc := "0" & fractx;
|
|
rexpon2 := resize (exponc, rexpon2'length);
|
|
leftright := false;
|
|
sticky := or (rfract (to_integer(shiftx)+rfract'high
|
|
- fracts'length downto 0));
|
|
elsif shiftx = 0 then
|
|
rexpon2 := resize (exponc, rexpon2'length);
|
|
sticky := or (rfract (rfract'high - fractc'length downto 0));
|
|
if rfract (rfract'high downto rfract'high - fractc'length+1) > fractx
|
|
then
|
|
fractc := "0" & fractx;
|
|
fracts := rfract (rfract'high downto rfract'high
|
|
- fracts'length+1);
|
|
leftright := false;
|
|
else
|
|
fractc := rfract (rfract'high downto rfract'high
|
|
- fractc'length+1);
|
|
fracts := "0" & fractx;
|
|
leftright := true;
|
|
end if;
|
|
elsif shiftx > fractx'high then
|
|
rexpon2 := rexpon;
|
|
fracts := (others => '0');
|
|
fractc := rfract (rfract'high downto rfract'high - fractc'length+1);
|
|
leftright := true;
|
|
sticky := or (fractx & rfract (rfract'high - fractc'length
|
|
downto 0));
|
|
else -- fractx'high > shiftx > 0
|
|
rexpon2 := rexpon;
|
|
fracts := "0" & shift_right (fractx, to_integer (shiftx));
|
|
fractc := rfract (rfract'high downto rfract'high - fractc'length+1);
|
|
leftright := true;
|
|
sticky := or (fractx (to_integer (shiftx) downto 0)
|
|
& rfract (rfract'high - fractc'length downto 0));
|
|
end if;
|
|
fracts (0) := fracts (0) or sticky; -- Or the sticky bit into the LSB
|
|
if fp_sign = to_X01(c(c'high)) then
|
|
ufract := fractc + fracts;
|
|
fp_sign := fp_sign;
|
|
else -- signs are different
|
|
ufract := fractc - fracts; -- always positive result
|
|
if leftright then -- Figure out which sign to use
|
|
fp_sign := fp_sign;
|
|
else
|
|
fp_sign := c(c'high);
|
|
end if;
|
|
end if;
|
|
-- normalize
|
|
fpresult := normalize (fract => ufract,
|
|
expon => rexpon2,
|
|
sign => fp_sign,
|
|
sticky => sticky,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => guard);
|
|
end if;
|
|
return fpresult;
|
|
end function mac;
|
|
|
|
-- "rem" function
|
|
function remainder (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
constant divguard : NATURAL := guard; -- division guard bits
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable ulfract, urfract : UNSIGNED (fraction_width downto 0);
|
|
variable fractr, fractl : UNSIGNED (fraction_width+divguard downto 0); -- right
|
|
variable rfract : UNSIGNED (fractr'range); -- result fraction
|
|
variable sfract : UNSIGNED (fraction_width+divguard downto 0); -- result fraction
|
|
variable exponl, exponr : SIGNED (exponent_width-1 downto 0); -- exponents
|
|
variable rexpon : SIGNED (exponent_width downto 0); -- result exponent
|
|
variable fp_sign : STD_ULOGIC; -- sign of result
|
|
variable shifty : INTEGER; -- denormal number shift
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- remainder
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
if (lfptype = isx or rfptype = isx) then
|
|
fpresult := (others => 'X');
|
|
elsif (lfptype = nan or lfptype = quiet_nan)
|
|
or (rfptype = nan or rfptype = quiet_nan)
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
or (lfptype = pos_inf or lfptype = neg_inf) -- inf rem x
|
|
-- Return quiet NAN, IEEE754-1985-7.1,5
|
|
or (rfptype = pos_zero or rfptype = neg_zero) then -- x rem 0
|
|
-- Return quiet NAN, IEEE754-1985-7.1,5
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (rfptype = pos_inf or rfptype = neg_inf) then -- x rem inf = 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (abs(l) < abs(r)) then
|
|
fpresult := l;
|
|
else
|
|
fp_sign := to_X01(l(l'high)); -- sign
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
lfptype := Classfp (lresize, false); -- errors already checked
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rfptype := Classfp (rresize, false); -- errors already checked
|
|
fractl := (others => '0');
|
|
break_number (
|
|
arg => lresize,
|
|
fptyp => lfptype,
|
|
denormalize => denormalize,
|
|
fract => ulfract,
|
|
expon => exponl);
|
|
fractl (fraction_width+divguard downto divguard) := ulfract;
|
|
-- right side
|
|
fractr := (others => '0');
|
|
break_number (
|
|
arg => rresize,
|
|
fptyp => rfptype,
|
|
denormalize => denormalize,
|
|
fract => urfract,
|
|
expon => exponr);
|
|
fractr (fraction_width+divguard downto divguard) := urfract;
|
|
rexpon := (exponr(exponr'high)&exponr);
|
|
shifty := to_integer(exponl - rexpon);
|
|
if (shifty > 0) then
|
|
fractr := shift_right (fractr, shifty);
|
|
rexpon := rexpon + shifty;
|
|
end if;
|
|
if (fractr /= 0) then
|
|
-- rem
|
|
rfract := fractl rem fractr; -- unsigned rem
|
|
sfract := rfract (sfract'range); -- lower bits
|
|
-- normalize
|
|
fpresult := normalize (fract => sfract,
|
|
expon => rexpon,
|
|
sign => fp_sign,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => divguard);
|
|
else
|
|
-- If we shift "fractr" so far that it becomes zero, return zero.
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
end if;
|
|
end if;
|
|
return fpresult;
|
|
end function remainder;
|
|
|
|
-- "mod" function
|
|
function modulo (
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant guard : NATURAL := float_guard_bits; -- number of guard bits
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := - mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable fpresult : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable remres : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- remainder
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
lfptype := isx;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
if (lfptype = isx or rfptype = isx) then
|
|
fpresult := (others => 'X');
|
|
elsif (lfptype = nan or lfptype = quiet_nan)
|
|
or (rfptype = nan or rfptype = quiet_nan)
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
or (lfptype = pos_inf or lfptype = neg_inf) -- inf rem x
|
|
-- Return quiet NAN, IEEE754-1985-7.1,5
|
|
or (rfptype = pos_zero or rfptype = neg_zero) then -- x rem 0
|
|
-- Return quiet NAN, IEEE754-1985-7.1,5
|
|
fpresult := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (rfptype = pos_inf or rfptype = neg_inf) then -- x rem inf = 0
|
|
fpresult := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
remres := remainder (l => abs(l),
|
|
r => abs(r),
|
|
round_style => round_style,
|
|
guard => guard,
|
|
check_error => false,
|
|
denormalize => denormalize);
|
|
-- MOD is the same as REM, but you do something different with
|
|
-- negative values
|
|
if (Is_Negative (l)) then
|
|
remres := - remres;
|
|
end if;
|
|
if (Is_Negative (l) = Is_Negative (r) or remres = 0) then
|
|
fpresult := remres;
|
|
else
|
|
fpresult := add (l => remres,
|
|
r => r,
|
|
round_style => round_style,
|
|
guard => guard,
|
|
check_error => false,
|
|
denormalize => denormalize);
|
|
end if;
|
|
end if;
|
|
return fpresult;
|
|
end function modulo;
|
|
|
|
-- Square root of a floating point number. Done using Newton's Iteration.
|
|
function sqrt (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style;
|
|
constant guard : NATURAL := float_guard_bits;
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := guard-arg'low; -- length of FP output fraction
|
|
constant exponent_width : NATURAL := arg'high; -- length of FP output exponent
|
|
variable sign : STD_ULOGIC;
|
|
variable fpresult : float (arg'range);
|
|
variable fptype : valid_fpstate;
|
|
variable iexpon : SIGNED(exponent_width-1 downto 0); -- exponents
|
|
variable expon : SIGNED(exponent_width downto 0); -- exponents
|
|
variable ufact : ufixed (0 downto arg'low);
|
|
variable fact : ufixed (2 downto -fraction_width); -- fraction
|
|
variable resb : ufixed (fact'high+1 downto fact'low);
|
|
begin -- square root
|
|
fptype := Classfp (arg, check_error);
|
|
classcase : case fptype is
|
|
when isx =>
|
|
fpresult := (others => 'X');
|
|
when nan | quiet_nan |
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
neg_normal | neg_denormal | neg_inf => -- sqrt (neg)
|
|
-- Return quiet NAN, IEEE754-1985-7.1.6
|
|
fpresult := qnanfp (fraction_width => fraction_width-guard,
|
|
exponent_width => exponent_width);
|
|
when pos_inf => -- Sqrt (inf), return infinity
|
|
fpresult := pos_inffp (fraction_width => fraction_width-guard,
|
|
exponent_width => exponent_width);
|
|
when pos_zero => -- return 0
|
|
fpresult := zerofp (fraction_width => fraction_width-guard,
|
|
exponent_width => exponent_width);
|
|
when neg_zero => -- IEEE754-1985-6.3 return -0
|
|
fpresult := neg_zerofp (fraction_width => fraction_width-guard,
|
|
exponent_width => exponent_width);
|
|
when others =>
|
|
break_number (arg => arg,
|
|
denormalize => denormalize,
|
|
check_error => false,
|
|
fract => ufact,
|
|
expon => iexpon,
|
|
sign => sign);
|
|
expon := resize (iexpon+1, expon'length); -- get exponent
|
|
fact := resize (ufact, fact'high, fact'low);
|
|
if (expon(0) = '1') then
|
|
fact := fact sla 1; -- * 2.0
|
|
end if;
|
|
expon := shift_right (expon, 1); -- exponent/2
|
|
-- Newton's iteration - root := (1 + arg) / 2
|
|
resb := (fact + 1) sra 1;
|
|
for j in 0 to fraction_width/4 loop
|
|
-- root := (root + (arg/root))/2
|
|
resb := resize (arg => (resb + (fact/resb)) sra 1,
|
|
left_index => resb'high,
|
|
right_index => resb'low,
|
|
round_style => fixed_truncate,
|
|
overflow_style => fixed_wrap);
|
|
end loop;
|
|
fpresult := normalize (fract => resb,
|
|
expon => expon-1,
|
|
sign => '0',
|
|
exponent_width => arg'high,
|
|
fraction_width => -arg'low,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => guard);
|
|
end case classcase;
|
|
return fpresult;
|
|
end function sqrt;
|
|
|
|
function Is_Negative (arg : UNRESOLVED_float) return BOOLEAN is
|
|
-- Technically -0 should return "false", but I'm leaving that case out.
|
|
begin
|
|
return (to_x01(arg(arg'high)) = '1');
|
|
end function Is_Negative;
|
|
|
|
-- compare functions
|
|
-- =, /=, >=, <=, <, >
|
|
|
|
function eq ( -- equal =
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return BOOLEAN
|
|
is
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable is_equal, is_unordered : BOOLEAN;
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- equal
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
return false;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
end if;
|
|
if (lfptype = neg_zero or lfptype = pos_zero) and
|
|
(rfptype = neg_zero or rfptype = pos_zero) then
|
|
is_equal := true;
|
|
else
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
is_equal := (to_slv(lresize) = to_slv(rresize));
|
|
end if;
|
|
if (check_error) then
|
|
is_unordered := Unordered (x => l,
|
|
y => r);
|
|
else
|
|
is_unordered := false;
|
|
end if;
|
|
return is_equal and not is_unordered;
|
|
end function eq;
|
|
|
|
function lt ( -- less than <
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return BOOLEAN
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable expl, expr : UNSIGNED (exponent_width-1 downto 0);
|
|
variable fractl, fractr : UNSIGNED (fraction_width-1 downto 0);
|
|
variable is_less_than, is_unordered : BOOLEAN;
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
is_less_than := false;
|
|
else
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
if to_x01(l(l'high)) = to_x01(r(r'high)) then -- sign bits
|
|
expl := UNSIGNED(lresize(exponent_width-1 downto 0));
|
|
expr := UNSIGNED(rresize(exponent_width-1 downto 0));
|
|
if expl = expr then
|
|
fractl := UNSIGNED (to_slv(lresize(-1 downto -fraction_width)));
|
|
fractr := UNSIGNED (to_slv(rresize(-1 downto -fraction_width)));
|
|
if to_x01(l(l'high)) = '0' then -- positive number
|
|
is_less_than := (fractl < fractr);
|
|
else
|
|
is_less_than := (fractl > fractr); -- negative
|
|
end if;
|
|
else
|
|
if to_x01(l(l'high)) = '0' then -- positive number
|
|
is_less_than := (expl < expr);
|
|
else
|
|
is_less_than := (expl > expr); -- negative
|
|
end if;
|
|
end if;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
if (lfptype = neg_zero and rfptype = pos_zero) then
|
|
is_less_than := false; -- -0 < 0 returns false.
|
|
else
|
|
is_less_than := (to_x01(l(l'high)) > to_x01(r(r'high)));
|
|
end if;
|
|
end if;
|
|
end if;
|
|
if check_error then
|
|
is_unordered := Unordered (x => l,
|
|
y => r);
|
|
else
|
|
is_unordered := false;
|
|
end if;
|
|
return is_less_than and not is_unordered;
|
|
end function lt;
|
|
|
|
function gt ( -- greater than >
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return BOOLEAN
|
|
is
|
|
constant fraction_width : NATURAL := -mine(l'low, r'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(l'high, r'high); -- length of FP output exponent
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable expl, expr : UNSIGNED (exponent_width-1 downto 0);
|
|
variable fractl, fractr : UNSIGNED (fraction_width-1 downto 0);
|
|
variable is_greater_than : BOOLEAN;
|
|
variable is_unordered : BOOLEAN;
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- greater_than
|
|
if (fraction_width = 0 or l'length < 7 or r'length < 7) then
|
|
is_greater_than := false;
|
|
else
|
|
lresize := resize (arg => to_X01(l),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
rresize := resize (arg => to_X01(r),
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => denormalize,
|
|
denormalize => denormalize);
|
|
if to_x01(l(l'high)) = to_x01(r(r'high)) then -- sign bits
|
|
expl := UNSIGNED(lresize(exponent_width-1 downto 0));
|
|
expr := UNSIGNED(rresize(exponent_width-1 downto 0));
|
|
if expl = expr then
|
|
fractl := UNSIGNED (to_slv(lresize(-1 downto -fraction_width)));
|
|
fractr := UNSIGNED (to_slv(rresize(-1 downto -fraction_width)));
|
|
if to_x01(l(l'high)) = '0' then -- positive number
|
|
is_greater_than := fractl > fractr;
|
|
else
|
|
is_greater_than := fractl < fractr; -- negative
|
|
end if;
|
|
else
|
|
if to_x01(l(l'high)) = '0' then -- positive number
|
|
is_greater_than := expl > expr;
|
|
else
|
|
is_greater_than := expl < expr; -- negative
|
|
end if;
|
|
end if;
|
|
else
|
|
lfptype := Classfp (l, check_error);
|
|
rfptype := Classfp (r, check_error);
|
|
if (lfptype = pos_zero and rfptype = neg_zero) then
|
|
is_greater_than := false; -- 0 > -0 returns false.
|
|
else
|
|
is_greater_than := to_x01(l(l'high)) < to_x01(r(r'high));
|
|
end if;
|
|
end if;
|
|
end if;
|
|
if check_error then
|
|
is_unordered := Unordered (x => l,
|
|
y => r);
|
|
else
|
|
is_unordered := false;
|
|
end if;
|
|
return is_greater_than and not is_unordered;
|
|
end function gt;
|
|
|
|
-- purpose: /= function
|
|
function ne ( -- not equal /=
|
|
l, r : UNRESOLVED_float;
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return BOOLEAN
|
|
is
|
|
variable is_equal, is_unordered : BOOLEAN;
|
|
begin
|
|
is_equal := eq (l => l,
|
|
r => r,
|
|
check_error => false,
|
|
denormalize => denormalize);
|
|
if check_error then
|
|
is_unordered := Unordered (x => l,
|
|
y => r);
|
|
else
|
|
is_unordered := false;
|
|
end if;
|
|
return not (is_equal and not is_unordered);
|
|
end function ne;
|
|
|
|
function le ( -- less than or equal to <=
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return BOOLEAN
|
|
is
|
|
variable is_greater_than, is_unordered : BOOLEAN;
|
|
begin
|
|
is_greater_than := gt (l => l,
|
|
r => r,
|
|
check_error => false,
|
|
denormalize => denormalize);
|
|
if check_error then
|
|
is_unordered := Unordered (x => l,
|
|
y => r);
|
|
else
|
|
is_unordered := false;
|
|
end if;
|
|
return not is_greater_than and not is_unordered;
|
|
end function le;
|
|
|
|
function ge ( -- greater than or equal to >=
|
|
l, r : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return BOOLEAN
|
|
is
|
|
variable is_less_than, is_unordered : BOOLEAN;
|
|
begin
|
|
is_less_than := lt (l => l,
|
|
r => r,
|
|
check_error => false,
|
|
denormalize => denormalize);
|
|
if check_error then
|
|
is_unordered := Unordered (x => l,
|
|
y => r);
|
|
else
|
|
is_unordered := false;
|
|
end if;
|
|
return not is_less_than and not is_unordered;
|
|
end function ge;
|
|
|
|
function "?=" (L, R : UNRESOLVED_float) return STD_ULOGIC is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(L'high, R'high); -- length of FP output exponent
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable is_equal, is_unordered : STD_ULOGIC;
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- ?=
|
|
if (fraction_width = 0 or L'length < 7 or R'length < 7) then
|
|
return 'X';
|
|
else
|
|
lfptype := Classfp (L, float_check_error);
|
|
rfptype := Classfp (R, float_check_error);
|
|
end if;
|
|
if (lfptype = neg_zero or lfptype = pos_zero) and
|
|
(rfptype = neg_zero or rfptype = pos_zero) then
|
|
is_equal := '1';
|
|
else
|
|
lresize := resize (arg => L,
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => float_denormalize,
|
|
denormalize => float_denormalize);
|
|
rresize := resize (arg => R,
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => float_denormalize,
|
|
denormalize => float_denormalize);
|
|
is_equal := to_sulv(lresize) ?= to_sulv(rresize);
|
|
end if;
|
|
if (float_check_error) then
|
|
if (lfptype = nan or lfptype = quiet_nan or
|
|
rfptype = nan or rfptype = quiet_nan) then
|
|
is_unordered := '1';
|
|
else
|
|
is_unordered := '0';
|
|
end if;
|
|
else
|
|
is_unordered := '0';
|
|
end if;
|
|
return is_equal and not is_unordered;
|
|
end function "?=";
|
|
|
|
function "?/=" (L, R : UNRESOLVED_float) return STD_ULOGIC is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(L'high, R'high); -- length of FP output exponent
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
variable is_equal, is_unordered : STD_ULOGIC;
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- ?/=
|
|
if (fraction_width = 0 or L'length < 7 or R'length < 7) then
|
|
return 'X';
|
|
else
|
|
lfptype := Classfp (L, float_check_error);
|
|
rfptype := Classfp (R, float_check_error);
|
|
end if;
|
|
if (lfptype = neg_zero or lfptype = pos_zero) and
|
|
(rfptype = neg_zero or rfptype = pos_zero) then
|
|
is_equal := '1';
|
|
else
|
|
lresize := resize (arg => L,
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => float_denormalize,
|
|
denormalize => float_denormalize);
|
|
rresize := resize (arg => R,
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
denormalize_in => float_denormalize,
|
|
denormalize => float_denormalize);
|
|
is_equal := to_sulv(lresize) ?= to_sulv(rresize);
|
|
end if;
|
|
if (float_check_error) then
|
|
if (lfptype = nan or lfptype = quiet_nan or
|
|
rfptype = nan or rfptype = quiet_nan) then
|
|
is_unordered := '1';
|
|
else
|
|
is_unordered := '0';
|
|
end if;
|
|
else
|
|
is_unordered := '0';
|
|
end if;
|
|
return not (is_equal and not is_unordered);
|
|
end function "?/=";
|
|
|
|
function "?>" (L, R : UNRESOLVED_float) return STD_ULOGIC is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low);
|
|
variable founddash : BOOLEAN := false;
|
|
begin
|
|
if (fraction_width = 0 or L'length < 7 or R'length < 7) then
|
|
return 'X';
|
|
else
|
|
for i in L'range loop
|
|
if L(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
for i in R'range loop
|
|
if R(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
if founddash then
|
|
report float_generic_pkg'instance_name
|
|
& " ""?>"": '-' found in compare string"
|
|
severity error;
|
|
return 'X';
|
|
elsif Is_X(L) or Is_X(R) then
|
|
return 'X';
|
|
elsif L > R then
|
|
return '1';
|
|
else
|
|
return '0';
|
|
end if;
|
|
end if;
|
|
end function "?>";
|
|
|
|
function "?>=" (L, R : UNRESOLVED_float) return STD_ULOGIC is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low);
|
|
variable founddash : BOOLEAN := false;
|
|
begin
|
|
if (fraction_width = 0 or L'length < 7 or R'length < 7) then
|
|
return 'X';
|
|
else
|
|
for i in L'range loop
|
|
if L(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
for i in R'range loop
|
|
if R(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
if founddash then
|
|
report float_generic_pkg'instance_name
|
|
& " ""?>="": '-' found in compare string"
|
|
severity error;
|
|
return 'X';
|
|
elsif Is_X(L) or Is_X(R) then
|
|
return 'X';
|
|
elsif L >= R then
|
|
return '1';
|
|
else
|
|
return '0';
|
|
end if;
|
|
end if;
|
|
end function "?>=";
|
|
|
|
function "?<" (L, R : UNRESOLVED_float) return STD_ULOGIC is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low);
|
|
variable founddash : BOOLEAN := false;
|
|
begin
|
|
if (fraction_width = 0 or L'length < 7 or R'length < 7) then
|
|
return 'X';
|
|
else
|
|
for i in L'range loop
|
|
if L(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
for i in R'range loop
|
|
if R(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
if founddash then
|
|
report float_generic_pkg'instance_name
|
|
& " ""?<"": '-' found in compare string"
|
|
severity error;
|
|
return 'X';
|
|
elsif Is_X(L) or Is_X(R) then
|
|
return 'X';
|
|
elsif L < R then
|
|
return '1';
|
|
else
|
|
return '0';
|
|
end if;
|
|
end if;
|
|
end function "?<";
|
|
|
|
function "?<=" (L, R : UNRESOLVED_float) return STD_ULOGIC is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low);
|
|
variable founddash : BOOLEAN := false;
|
|
begin
|
|
if (fraction_width = 0 or L'length < 7 or R'length < 7) then
|
|
return 'X';
|
|
else
|
|
for i in L'range loop
|
|
if L(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
for i in R'range loop
|
|
if R(i) = '-' then
|
|
founddash := true;
|
|
end if;
|
|
end loop;
|
|
if founddash then
|
|
report float_generic_pkg'instance_name
|
|
& " ""?<="": '-' found in compare string"
|
|
severity error;
|
|
return 'X';
|
|
elsif Is_X(L) or Is_X(R) then
|
|
return 'X';
|
|
elsif L <= R then
|
|
return '1';
|
|
else
|
|
return '0';
|
|
end if;
|
|
end if;
|
|
end function "?<=";
|
|
|
|
function std_match (L, R : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
return std_match(to_sulv(L), to_sulv(R));
|
|
else
|
|
report float_generic_pkg'instance_name
|
|
& "STD_MATCH: L'RANGE /= R'RANGE, returning FALSE"
|
|
severity warning;
|
|
return false;
|
|
end if;
|
|
end function std_match;
|
|
|
|
function find_rightmost (arg : UNRESOLVED_float; y : STD_ULOGIC) return INTEGER is
|
|
begin
|
|
for_loop : for i in arg'reverse_range loop
|
|
if arg(i) ?= y then
|
|
return i;
|
|
end if;
|
|
end loop;
|
|
return arg'high+1; -- return out of bounds 'high
|
|
end function find_rightmost;
|
|
|
|
function find_leftmost (arg : UNRESOLVED_float; y : STD_ULOGIC) return INTEGER is
|
|
begin
|
|
for_loop : for i in arg'range loop
|
|
if arg(i) ?= y then
|
|
return i;
|
|
end if;
|
|
end loop;
|
|
return arg'low-1; -- return out of bounds 'low
|
|
end function find_leftmost;
|
|
|
|
-- These override the defaults for the compare operators.
|
|
function "=" (l, r : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
return eq(l, r);
|
|
end function "=";
|
|
|
|
function "/=" (l, r : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
return ne(l, r);
|
|
end function "/=";
|
|
|
|
function ">=" (l, r : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
return ge(l, r);
|
|
end function ">=";
|
|
|
|
function "<=" (l, r : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
return le(l, r);
|
|
end function "<=";
|
|
|
|
function ">" (l, r : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
return gt(l, r);
|
|
end function ">";
|
|
|
|
function "<" (l, r : UNRESOLVED_float) return BOOLEAN is
|
|
begin
|
|
return lt(l, r);
|
|
end function "<";
|
|
|
|
-- purpose: maximum of two numbers (overrides default)
|
|
function maximum (
|
|
L, R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(L'high, R'high); -- length of FP output exponent
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin
|
|
if ((L'length < 1) or (R'length < 1)) then return NAFP;
|
|
end if;
|
|
lresize := resize (L, exponent_width, fraction_width);
|
|
rresize := resize (R, exponent_width, fraction_width);
|
|
if lresize > rresize then return lresize;
|
|
else return rresize;
|
|
end if;
|
|
end function maximum;
|
|
|
|
function minimum (
|
|
L, R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(L'low, R'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := maximum(L'high, R'high); -- length of FP output exponent
|
|
variable lresize, rresize : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin
|
|
if ((L'length < 1) or (R'length < 1)) then return NAFP;
|
|
end if;
|
|
lresize := resize (L, exponent_width, fraction_width);
|
|
rresize := resize (R, exponent_width, fraction_width);
|
|
if lresize > rresize then return rresize;
|
|
else return lresize;
|
|
end if;
|
|
end function minimum;
|
|
|
|
-----------------------------------------------------------------------------
|
|
-- conversion functions
|
|
-----------------------------------------------------------------------------
|
|
|
|
-- Converts a floating point number of one format into another format
|
|
function resize (
|
|
arg : UNRESOLVED_float; -- Floating point input
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- length of FP output fraction
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize_in : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant in_fraction_width : NATURAL := -arg'low; -- length of FP output fraction
|
|
constant in_exponent_width : NATURAL := arg'high; -- length of FP output exponent
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
-- result value
|
|
variable fptype : valid_fpstate;
|
|
variable expon_in : SIGNED (in_exponent_width-1 downto 0);
|
|
variable fract_in : UNSIGNED (in_fraction_width downto 0);
|
|
variable expon_out : SIGNED (exponent_width-1 downto 0); -- output fract
|
|
variable fract_out : UNSIGNED (fraction_width downto 0); -- output fract
|
|
begin
|
|
fptype := Classfp(arg, check_error);
|
|
if ((fptype = pos_denormal or fptype = neg_denormal) and denormalize_in
|
|
and (in_exponent_width < exponent_width
|
|
or in_fraction_width < fraction_width))
|
|
or in_exponent_width > exponent_width
|
|
or in_fraction_width > fraction_width then
|
|
-- size reduction
|
|
classcase : case fptype is
|
|
when isx =>
|
|
result := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
result := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_inf =>
|
|
result := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when neg_inf =>
|
|
result := neg_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when pos_zero | neg_zero =>
|
|
result := zerofp (fraction_width => fraction_width, -- hate -0
|
|
exponent_width => exponent_width);
|
|
when others =>
|
|
break_number (
|
|
arg => arg,
|
|
fptyp => fptype,
|
|
denormalize => denormalize_in,
|
|
fract => fract_in,
|
|
expon => expon_in);
|
|
if fraction_width > in_fraction_width and denormalize_in then
|
|
-- You only get here if you have a denormal input
|
|
fract_out := (others => '0'); -- pad with zeros
|
|
fract_out (fraction_width downto
|
|
fraction_width - in_fraction_width) := fract_in;
|
|
result := normalize (
|
|
fract => fract_out,
|
|
expon => expon_in,
|
|
sign => arg(arg'high),
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => 0);
|
|
else
|
|
result := normalize (
|
|
fract => fract_in,
|
|
expon => expon_in,
|
|
sign => arg(arg'high),
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => in_fraction_width - fraction_width);
|
|
end if;
|
|
end case classcase;
|
|
else -- size increase or the same size
|
|
if exponent_width > in_exponent_width then
|
|
expon_in := SIGNED(arg (in_exponent_width-1 downto 0));
|
|
if fptype = pos_zero or fptype = neg_zero then
|
|
result (exponent_width-1 downto 0) := (others => '0');
|
|
elsif expon_in = -1 then -- inf or nan (shorts out check_error)
|
|
result (exponent_width-1 downto 0) := (others => '1');
|
|
else
|
|
-- invert top BIT
|
|
expon_in(expon_in'high) := not expon_in(expon_in'high);
|
|
expon_out := resize (expon_in, expon_out'length); -- signed expand
|
|
-- Flip it back.
|
|
expon_out(expon_out'high) := not expon_out(expon_out'high);
|
|
result (exponent_width-1 downto 0) := UNRESOLVED_float(expon_out);
|
|
end if;
|
|
result (exponent_width) := arg (in_exponent_width); -- sign
|
|
else -- exponent_width = in_exponent_width
|
|
result (exponent_width downto 0) := arg (in_exponent_width downto 0);
|
|
end if;
|
|
if fraction_width > in_fraction_width then
|
|
result (-1 downto -fraction_width) := (others => '0'); -- zeros
|
|
result (-1 downto -in_fraction_width) :=
|
|
arg (-1 downto -in_fraction_width);
|
|
else -- fraction_width = in_fraciton_width
|
|
result (-1 downto -fraction_width) :=
|
|
arg (-1 downto -in_fraction_width);
|
|
end if;
|
|
end if;
|
|
return result;
|
|
end function resize;
|
|
|
|
function resize (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize_in : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := resize (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize_in => denormalize_in,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end if;
|
|
end function resize;
|
|
|
|
function to_float32 (
|
|
arg : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize_in : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float32 is
|
|
begin
|
|
return resize (arg => arg,
|
|
exponent_width => float32'high,
|
|
fraction_width => -float32'low,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize_in => denormalize_in,
|
|
denormalize => denormalize);
|
|
end function to_float32;
|
|
|
|
function to_float64 (
|
|
arg : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize_in : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float64 is
|
|
begin
|
|
return resize (arg => arg,
|
|
exponent_width => float64'high,
|
|
fraction_width => -float64'low,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize_in => denormalize_in,
|
|
denormalize => denormalize);
|
|
end function to_float64;
|
|
|
|
function to_float128 (
|
|
arg : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error;
|
|
constant denormalize_in : BOOLEAN := float_denormalize; -- Use IEEE extended FP
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float128 is
|
|
begin
|
|
return resize (arg => arg,
|
|
exponent_width => float128'high,
|
|
fraction_width => -float128'low,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize_in => denormalize_in,
|
|
denormalize => denormalize);
|
|
end function to_float128;
|
|
|
|
-- to_float (Real)
|
|
-- typically not Synthesizable unless the input is a constant.
|
|
function to_float (
|
|
arg : REAL;
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- length of FP output fraction
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable arg_real : REAL; -- Real version of argument
|
|
variable validfp : boundary_type; -- Check for valid results
|
|
variable exp : INTEGER; -- Integer version of exponent
|
|
variable expon : UNSIGNED (exponent_width - 1 downto 0);
|
|
-- Unsigned version of exp.
|
|
constant expon_base : SIGNED (exponent_width-1 downto 0) :=
|
|
gen_expon_base(exponent_width); -- exponent offset
|
|
variable fract : UNSIGNED (fraction_width-1 downto 0);
|
|
variable frac : REAL; -- Real version of fraction
|
|
constant roundfrac : REAL := 2.0 ** (-2 - fract'high); -- used for rounding
|
|
variable round : BOOLEAN; -- to round or not to round
|
|
begin
|
|
result := (others => '0');
|
|
arg_real := arg;
|
|
if arg_real < 0.0 then
|
|
result (exponent_width) := '1';
|
|
arg_real := - arg_real; -- Make it positive.
|
|
else
|
|
result (exponent_width) := '0';
|
|
end if;
|
|
test_boundary (arg => arg_real,
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
denormalize => denormalize,
|
|
btype => validfp,
|
|
log2i => exp);
|
|
if validfp = zero then
|
|
return result; -- Result initialized to "0".
|
|
elsif validfp = infinity then
|
|
result (exponent_width - 1 downto 0) := (others => '1'); -- Exponent all "1"
|
|
-- return infinity.
|
|
return result;
|
|
else
|
|
if validfp = denormal then -- Exponent will default to "0".
|
|
expon := (others => '0');
|
|
frac := arg_real * (2.0 ** (to_integer(expon_base)-1));
|
|
else -- Number less than 1. "normal" number
|
|
expon := UNSIGNED (to_signed (exp-1, exponent_width));
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
frac := (arg_real / 2.0 ** exp) - 1.0; -- Number less than 1.
|
|
end if;
|
|
for i in 0 to fract'high loop
|
|
if frac >= 2.0 ** (-1 - i) then
|
|
fract (fract'high - i) := '1';
|
|
frac := frac - 2.0 ** (-1 - i);
|
|
else
|
|
fract (fract'high - i) := '0';
|
|
end if;
|
|
end loop;
|
|
round := false;
|
|
case round_style is
|
|
when round_nearest =>
|
|
if frac > roundfrac or ((frac = roundfrac) and fract(0) = '1') then
|
|
round := true;
|
|
end if;
|
|
when round_inf =>
|
|
if frac /= 0.0 and result(exponent_width) = '0' then
|
|
round := true;
|
|
end if;
|
|
when round_neginf =>
|
|
if frac /= 0.0 and result(exponent_width) = '1' then
|
|
round := true;
|
|
end if;
|
|
when others =>
|
|
null; -- don't round
|
|
end case;
|
|
if (round) then
|
|
if and(fract) = '1' then -- fraction is all "1"
|
|
expon := expon + 1;
|
|
fract := (others => '0');
|
|
else
|
|
fract := fract + 1;
|
|
end if;
|
|
end if;
|
|
result (exponent_width-1 downto 0) := UNRESOLVED_float(expon);
|
|
result (-1 downto -fraction_width) := UNRESOLVED_float(fract);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- to_float (Integer)
|
|
function to_float (
|
|
arg : INTEGER;
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- length of FP output fraction
|
|
constant round_style : round_type := float_round_style) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable arg_int : NATURAL; -- Natural version of argument
|
|
variable expon : SIGNED (exponent_width-1 downto 0);
|
|
variable exptmp : SIGNED (exponent_width-1 downto 0);
|
|
-- Unsigned version of exp.
|
|
constant expon_base : SIGNED (exponent_width-1 downto 0) :=
|
|
gen_expon_base(exponent_width); -- exponent offset
|
|
variable fract : UNSIGNED (fraction_width-1 downto 0) := (others => '0');
|
|
variable fracttmp : UNSIGNED (fraction_width-1 downto 0);
|
|
variable round : BOOLEAN;
|
|
variable shift : NATURAL;
|
|
variable shiftr : NATURAL;
|
|
variable roundfrac : NATURAL; -- used in rounding
|
|
begin
|
|
if arg < 0 then
|
|
result (exponent_width) := '1';
|
|
arg_int := -arg; -- Make it positive.
|
|
else
|
|
result (exponent_width) := '0';
|
|
arg_int := arg;
|
|
end if;
|
|
if arg_int = 0 then
|
|
result := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
-- If the number is larger than we can represent in this number system
|
|
-- we need to return infinity.
|
|
shift := log2(arg_int);
|
|
if shift > to_integer(expon_base) then
|
|
-- worry about infinity
|
|
if result (exponent_width) = '0' then
|
|
result := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
-- return negative infinity.
|
|
result := neg_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
end if;
|
|
else -- Normal number (can't be denormal)
|
|
-- Compute Exponent
|
|
expon := to_signed (shift-1, expon'length); -- positive fraction.
|
|
-- Compute Fraction
|
|
arg_int := arg_int - 2**shift; -- Subtract off the 1.0
|
|
shiftr := shift;
|
|
for I in fract'high downto maximum (fract'high - shift + 1, 0) loop
|
|
shiftr := shiftr - 1;
|
|
if (arg_int >= 2**shiftr) then
|
|
arg_int := arg_int - 2**shiftr;
|
|
fract(I) := '1';
|
|
else
|
|
fract(I) := '0';
|
|
end if;
|
|
end loop;
|
|
-- Rounding routine
|
|
round := false;
|
|
if arg_int > 0 then
|
|
roundfrac := 2**(shiftr-1);
|
|
case round_style is
|
|
when round_nearest =>
|
|
if arg_int > roundfrac or
|
|
((arg_int = roundfrac) and fract(0) = '1') then
|
|
round := true;
|
|
end if;
|
|
when round_inf =>
|
|
if arg_int /= 0 and result (exponent_width) = '0' then
|
|
round := true;
|
|
end if;
|
|
when round_neginf =>
|
|
if arg_int /= 0 and result (exponent_width) = '1' then
|
|
round := true;
|
|
end if;
|
|
when others =>
|
|
null;
|
|
end case;
|
|
end if;
|
|
if round then
|
|
fp_round(fract_in => fract,
|
|
expon_in => expon,
|
|
fract_out => fracttmp,
|
|
expon_out => exptmp);
|
|
fract := fracttmp;
|
|
expon := exptmp;
|
|
end if;
|
|
-- Put the number together and return
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
result (exponent_width-1 downto 0) := UNRESOLVED_float(expon);
|
|
result (-1 downto -fraction_width) := UNRESOLVED_float(fract);
|
|
end if;
|
|
end if;
|
|
return result;
|
|
end function to_float;
|
|
|
|
-- to_float (unsigned)
|
|
function to_float (
|
|
arg : UNRESOLVED_UNSIGNED;
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- length of FP output fraction
|
|
constant round_style : round_type := float_round_style) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
constant ARG_LEFT : INTEGER := arg'length-1;
|
|
alias XARG : UNRESOLVED_UNSIGNED(ARG_LEFT downto 0) is arg;
|
|
variable sarg : SIGNED (ARG_LEFT+1 downto 0); -- signed version of arg
|
|
begin
|
|
if arg'length < 1 then
|
|
return NAFP;
|
|
end if;
|
|
sarg (XARG'range) := SIGNED (XARG);
|
|
sarg (sarg'high) := '0';
|
|
result := to_float (arg => sarg,
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
round_style => round_style);
|
|
return result;
|
|
end function to_float;
|
|
|
|
-- to_float (signed)
|
|
function to_float (
|
|
arg : UNRESOLVED_SIGNED;
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- length of FP output fraction
|
|
constant round_style : round_type := float_round_style) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
constant ARG_LEFT : INTEGER := arg'length-1;
|
|
alias XARG : UNRESOLVED_SIGNED(ARG_LEFT downto 0) is arg;
|
|
variable arg_int : UNSIGNED(XARG'range); -- Real version of argument
|
|
variable argb2 : UNSIGNED(XARG'high/2 downto 0); -- log2 of input
|
|
variable rexp : SIGNED (exponent_width - 1 downto 0);
|
|
variable exp : SIGNED (exponent_width - 1 downto 0);
|
|
-- signed version of exp.
|
|
variable expon : UNSIGNED (exponent_width - 1 downto 0);
|
|
-- Unsigned version of exp.
|
|
constant expon_base : SIGNED (exponent_width-1 downto 0) :=
|
|
gen_expon_base(exponent_width); -- exponent offset
|
|
variable round : BOOLEAN;
|
|
variable fract : UNSIGNED (fraction_width-1 downto 0);
|
|
variable rfract : UNSIGNED (fraction_width-1 downto 0);
|
|
variable sign : STD_ULOGIC; -- sign bit
|
|
begin
|
|
if arg'length < 1 then
|
|
return NAFP;
|
|
end if;
|
|
if Is_X (XARG) then
|
|
result := (others => 'X');
|
|
elsif (XARG = 0) then
|
|
result := zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else -- Normal number (can't be denormal)
|
|
sign := to_X01(XARG (XARG'high));
|
|
arg_int := UNSIGNED(abs (to_01(XARG)));
|
|
-- Compute Exponent
|
|
argb2 := to_unsigned(find_leftmost(arg_int, '1'), argb2'length); -- Log2
|
|
if argb2 > UNSIGNED(expon_base) then
|
|
result := pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
result (exponent_width) := sign;
|
|
else
|
|
exp := SIGNED(resize(argb2, exp'length));
|
|
arg_int := shift_left (arg_int, arg_int'high-to_integer(exp));
|
|
if (arg_int'high > fraction_width) then
|
|
fract := arg_int (arg_int'high-1 downto (arg_int'high-fraction_width));
|
|
round := check_round (
|
|
fract_in => fract (0),
|
|
sign => sign,
|
|
remainder => arg_int((arg_int'high-fraction_width-1)
|
|
downto 0),
|
|
round_style => round_style);
|
|
if round then
|
|
fp_round(fract_in => fract,
|
|
expon_in => exp,
|
|
fract_out => rfract,
|
|
expon_out => rexp);
|
|
else
|
|
rfract := fract;
|
|
rexp := exp;
|
|
end if;
|
|
else
|
|
rexp := exp;
|
|
rfract := (others => '0');
|
|
rfract (fraction_width-1 downto fraction_width-1-(arg_int'high-1)) :=
|
|
arg_int (arg_int'high-1 downto 0);
|
|
end if;
|
|
result (exponent_width) := sign;
|
|
expon := UNSIGNED (rexp-1);
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
result (exponent_width-1 downto 0) := UNRESOLVED_float(expon);
|
|
result (-1 downto -fraction_width) := UNRESOLVED_float(rfract);
|
|
end if;
|
|
end if;
|
|
return result;
|
|
end function to_float;
|
|
|
|
-- std_logic_vector to float
|
|
function to_float (
|
|
arg : STD_ULOGIC_VECTOR;
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- length of FP output fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
variable fpvar : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin
|
|
if arg'length < 1 then
|
|
return NAFP;
|
|
end if;
|
|
fpvar := UNRESOLVED_float(arg);
|
|
return fpvar;
|
|
end function to_float;
|
|
|
|
-- purpose: converts a ufixed to a floating point
|
|
function to_float (
|
|
arg : UNRESOLVED_ufixed; -- unsigned fixed point input
|
|
constant exponent_width : NATURAL := float_exponent_width; -- width of exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- width of fraction
|
|
constant round_style : round_type := float_round_style; -- rounding
|
|
constant denormalize : BOOLEAN := float_denormalize) -- use ieee extensions
|
|
return UNRESOLVED_float
|
|
is
|
|
variable sarg : sfixed (arg'high+1 downto arg'low); -- Signed version of arg
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
begin -- function to_float
|
|
if (arg'length < 1) then
|
|
return NAFP;
|
|
end if;
|
|
sarg (arg'range) := sfixed (arg);
|
|
sarg (sarg'high) := '0';
|
|
result := to_float (arg => sarg,
|
|
exponent_width => exponent_width,
|
|
fraction_width => fraction_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end function to_float;
|
|
|
|
function to_float (
|
|
arg : UNRESOLVED_sfixed; -- signed fixed point
|
|
constant exponent_width : NATURAL := float_exponent_width; -- length of FP output exponent
|
|
constant fraction_width : NATURAL := float_fraction_width; -- length of FP output fraction
|
|
constant round_style : round_type := float_round_style; -- rounding
|
|
constant denormalize : BOOLEAN := float_denormalize) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
constant integer_width : INTEGER := arg'high;
|
|
constant in_fraction_width : INTEGER := arg'low;
|
|
variable xresult : sfixed (integer_width downto in_fraction_width);
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable arg_int : UNSIGNED(integer_width - in_fraction_width
|
|
downto 0); -- unsigned version of argument
|
|
variable argx : SIGNED (integer_width - in_fraction_width downto 0);
|
|
variable exp, exptmp : SIGNED (exponent_width + 1 downto 0);
|
|
variable expon : UNSIGNED (exponent_width - 1 downto 0);
|
|
-- Unsigned version of exp.
|
|
constant expon_base : SIGNED (exponent_width-1 downto 0) :=
|
|
gen_expon_base(exponent_width); -- exponent offset
|
|
variable fract, fracttmp : UNSIGNED (fraction_width-1 downto 0) :=
|
|
(others => '0');
|
|
variable round : BOOLEAN := false;
|
|
begin
|
|
if (arg'length < 1) then
|
|
return NAFP;
|
|
end if;
|
|
xresult := to_01(arg, 'X');
|
|
argx := SIGNED(to_slv(xresult));
|
|
if (Is_X (arg)) then
|
|
result := (others => 'X');
|
|
elsif (argx = 0) then
|
|
result := (others => '0');
|
|
else
|
|
result := (others => '0'); -- zero out the result
|
|
if argx(argx'left) = '1' then -- toss the sign bit
|
|
result (exponent_width) := '1'; -- Negative number
|
|
arg_int := UNSIGNED(to_x01(not STD_LOGIC_VECTOR (argx))) + 1; -- Make it positive with two's complement
|
|
else
|
|
result (exponent_width) := '0';
|
|
arg_int := UNSIGNED(to_x01(STD_LOGIC_VECTOR (argx))); -- new line: direct conversion to unsigned
|
|
end if;
|
|
-- Compute Exponent
|
|
exp := to_signed(find_leftmost(arg_int, '1'), exp'length); -- Log2
|
|
if exp + in_fraction_width > expon_base then -- return infinity
|
|
result (-1 downto -fraction_width) := (others => '0');
|
|
result (exponent_width -1 downto 0) := (others => '1');
|
|
return result;
|
|
elsif (denormalize and
|
|
(exp + in_fraction_width <= -resize(expon_base, exp'length))) then
|
|
exp := -resize(expon_base, exp'length);
|
|
-- shift by a constant
|
|
arg_int := shift_left (arg_int,
|
|
(arg_int'high + to_integer(expon_base)
|
|
+ in_fraction_width - 1));
|
|
if (arg_int'high > fraction_width) then
|
|
fract := arg_int (arg_int'high-1 downto (arg_int'high-fraction_width));
|
|
round := check_round (
|
|
fract_in => arg_int(arg_int'high-fraction_width),
|
|
sign => result(result'high),
|
|
remainder => arg_int((arg_int'high-fraction_width-1)
|
|
downto 0),
|
|
round_style => round_style);
|
|
if (round) then
|
|
fp_round (fract_in => arg_int (arg_int'high-1 downto
|
|
(arg_int'high-fraction_width)),
|
|
expon_in => exp,
|
|
fract_out => fract,
|
|
expon_out => exptmp);
|
|
exp := exptmp;
|
|
end if;
|
|
else
|
|
fract (fraction_width-1 downto fraction_width-1-(arg_int'high-1)) :=
|
|
arg_int (arg_int'high-1 downto 0);
|
|
end if;
|
|
else
|
|
arg_int := shift_left (arg_int, arg_int'high-to_integer(exp));
|
|
exp := exp + in_fraction_width;
|
|
if (arg_int'high > fraction_width) then
|
|
fract := arg_int (arg_int'high-1 downto (arg_int'high-fraction_width));
|
|
round := check_round (
|
|
fract_in => fract(0),
|
|
sign => result(result'high),
|
|
remainder => arg_int((arg_int'high-fraction_width-1)
|
|
downto 0),
|
|
round_style => round_style);
|
|
if (round) then
|
|
fp_round (fract_in => fract,
|
|
expon_in => exp,
|
|
fract_out => fracttmp,
|
|
expon_out => exptmp);
|
|
fract := fracttmp;
|
|
exp := exptmp;
|
|
end if;
|
|
else
|
|
fract (fraction_width-1 downto fraction_width-1-(arg_int'high-1)) :=
|
|
arg_int (arg_int'high-1 downto 0);
|
|
end if;
|
|
end if;
|
|
expon := UNSIGNED (resize(exp-1, exponent_width));
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
result (exponent_width-1 downto 0) := UNRESOLVED_float(expon);
|
|
result (-1 downto -fraction_width) := UNRESOLVED_float(fract);
|
|
end if;
|
|
return result;
|
|
end function to_float;
|
|
|
|
-- size_res functions
|
|
-- Integer to float
|
|
function to_float (
|
|
arg : INTEGER;
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- real to float
|
|
function to_float (
|
|
arg : REAL;
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- unsigned to float
|
|
function to_float (
|
|
arg : UNRESOLVED_UNSIGNED;
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- signed to float
|
|
function to_float (
|
|
arg : UNRESOLVED_SIGNED;
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style) -- rounding
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- std_ulogic_vector to float
|
|
function to_float (
|
|
arg : STD_ULOGIC_VECTOR;
|
|
size_res : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- unsigned fixed point to float
|
|
function to_float (
|
|
arg : UNRESOLVED_ufixed; -- unsigned fixed point input
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding
|
|
constant denormalize : BOOLEAN := float_denormalize) -- use ieee extensions
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- signed fixed point to float
|
|
function to_float (
|
|
arg : UNRESOLVED_sfixed;
|
|
size_res : UNRESOLVED_float;
|
|
constant round_style : round_type := float_round_style; -- rounding
|
|
constant denormalize : BOOLEAN := float_denormalize) -- rounding option
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_float (arg => arg,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low,
|
|
round_style => round_style,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end if;
|
|
end function to_float;
|
|
|
|
-- to_integer (float)
|
|
function to_integer (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error) -- check for errors
|
|
return INTEGER
|
|
is
|
|
variable validfp : valid_fpstate; -- Valid FP state
|
|
variable frac : UNSIGNED (-arg'low downto 0); -- Fraction
|
|
variable fract : UNSIGNED (1-arg'low downto 0); -- Fraction
|
|
variable expon : SIGNED (arg'high-1 downto 0);
|
|
variable isign : STD_ULOGIC; -- internal version of sign
|
|
variable round : STD_ULOGIC; -- is rounding needed?
|
|
variable result : INTEGER;
|
|
variable base : INTEGER; -- Integer exponent
|
|
begin
|
|
validfp := Classfp (arg, check_error);
|
|
classcase : case validfp is
|
|
when isx | nan | quiet_nan | pos_zero | neg_zero | pos_denormal | neg_denormal =>
|
|
result := 0; -- return 0
|
|
when pos_inf =>
|
|
result := INTEGER'high;
|
|
when neg_inf =>
|
|
result := INTEGER'low;
|
|
when others =>
|
|
break_number (
|
|
arg => arg,
|
|
fptyp => validfp,
|
|
denormalize => false,
|
|
fract => frac,
|
|
expon => expon);
|
|
fract (fract'high) := '0'; -- Add extra bit for 0.6 case
|
|
fract (fract'high-1 downto 0) := frac;
|
|
isign := to_x01 (arg (arg'high));
|
|
base := to_integer (expon) + 1;
|
|
if base < -1 then
|
|
result := 0;
|
|
elsif base >= frac'high then
|
|
result := to_integer (fract) * 2**(base - frac'high);
|
|
else -- We need to round
|
|
if base = -1 then -- trap for 0.6 case.
|
|
result := 0;
|
|
else
|
|
result := to_integer (fract (frac'high downto frac'high-base));
|
|
end if;
|
|
-- rounding routine
|
|
case round_style is
|
|
when round_nearest =>
|
|
if frac'high - base > 1 then
|
|
round := fract (frac'high - base - 1) and
|
|
(fract (frac'high - base)
|
|
or (or (fract (frac'high - base - 2 downto 0))));
|
|
else
|
|
round := fract (frac'high - base - 1) and
|
|
fract (frac'high - base);
|
|
end if;
|
|
when round_inf =>
|
|
round := fract(frac'high - base - 1) and not isign;
|
|
when round_neginf =>
|
|
round := fract(frac'high - base - 1) and isign;
|
|
when others =>
|
|
round := '0';
|
|
end case;
|
|
if round = '1' then
|
|
result := result + 1;
|
|
end if;
|
|
end if;
|
|
if isign = '1' then
|
|
result := - result;
|
|
end if;
|
|
end case classcase;
|
|
return result;
|
|
end function to_integer;
|
|
|
|
-- to_unsigned (float)
|
|
function to_unsigned (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
constant size : NATURAL; -- length of output
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error) -- check for errors
|
|
return UNRESOLVED_UNSIGNED
|
|
is
|
|
variable validfp : valid_fpstate; -- Valid FP state
|
|
variable frac : UNRESOLVED_UNSIGNED (size-1 downto 0); -- Fraction
|
|
variable sign : STD_ULOGIC; -- not used
|
|
begin
|
|
validfp := Classfp (arg, check_error);
|
|
classcase : case validfp is
|
|
when isx | nan | quiet_nan =>
|
|
frac := (others => 'X');
|
|
when pos_zero | neg_inf | neg_zero | neg_normal | pos_denormal | neg_denormal =>
|
|
frac := (others => '0'); -- return 0
|
|
when pos_inf =>
|
|
frac := (others => '1');
|
|
when others =>
|
|
float_to_unsigned (
|
|
arg => arg,
|
|
frac => frac,
|
|
sign => sign,
|
|
denormalize => false,
|
|
bias => 0,
|
|
round_style => round_style);
|
|
end case classcase;
|
|
return (frac);
|
|
end function to_unsigned;
|
|
|
|
-- to_signed (float)
|
|
function to_signed (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
constant size : NATURAL; -- length of output
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error) -- check for errors
|
|
return UNRESOLVED_SIGNED
|
|
is
|
|
variable sign : STD_ULOGIC; -- true if negative
|
|
variable validfp : valid_fpstate; -- Valid FP state
|
|
variable frac : UNRESOLVED_UNSIGNED (size-1 downto 0); -- Fraction
|
|
variable result : UNRESOLVED_SIGNED (size-1 downto 0);
|
|
begin
|
|
validfp := Classfp (arg, check_error);
|
|
classcase : case validfp is
|
|
when isx | nan | quiet_nan =>
|
|
result := (others => 'X');
|
|
when pos_zero | neg_zero | pos_denormal | neg_denormal =>
|
|
result := (others => '0'); -- return 0
|
|
when pos_inf =>
|
|
result := (others => '1');
|
|
result (result'high) := '0';
|
|
when neg_inf =>
|
|
result := (others => '0');
|
|
result (result'high) := '1';
|
|
when others =>
|
|
float_to_unsigned (
|
|
arg => arg,
|
|
sign => sign,
|
|
frac => frac,
|
|
denormalize => false,
|
|
bias => 0,
|
|
round_style => round_style);
|
|
result (size-1) := '0';
|
|
result (size-2 downto 0) := UNRESOLVED_SIGNED(frac (size-2 downto 0));
|
|
if sign = '1' then
|
|
-- Because the most negative signed number is 1 less than the most
|
|
-- positive signed number, we need this code.
|
|
if frac(frac'high) = '1' then -- return most negative number
|
|
result := (others => '0');
|
|
result (result'high) := '1';
|
|
else
|
|
result := -result;
|
|
end if;
|
|
else
|
|
if frac(frac'high) = '1' then -- return most positive number
|
|
result := (others => '1');
|
|
result (result'high) := '0';
|
|
end if;
|
|
end if;
|
|
end case classcase;
|
|
return result;
|
|
end function to_signed;
|
|
|
|
-- purpose: Converts a float to ufixed
|
|
function to_ufixed (
|
|
arg : UNRESOLVED_float; -- fp input
|
|
constant left_index : INTEGER; -- integer part
|
|
constant right_index : INTEGER; -- fraction part
|
|
constant overflow_style : fixed_overflow_style_type := fixed_overflow_style; -- saturate
|
|
constant round_style : fixed_round_style_type := fixed_round_style; -- rounding
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return UNRESOLVED_ufixed
|
|
is
|
|
constant fraction_width : INTEGER := -mine(arg'low, arg'low); -- length of FP output fraction
|
|
constant exponent_width : INTEGER := arg'high; -- length of FP output exponent
|
|
constant size : INTEGER := left_index - right_index + 4; -- unsigned size
|
|
variable expon_base : INTEGER; -- exponent offset
|
|
variable validfp : valid_fpstate; -- Valid FP state
|
|
variable exp : INTEGER; -- Exponent
|
|
variable expon : UNSIGNED (exponent_width-1 downto 0); -- Vectorized exponent
|
|
-- Base to divide fraction by
|
|
variable frac : UNSIGNED (size-1 downto 0) := (others => '0'); -- Fraction
|
|
variable frac_shift : UNSIGNED (size-1 downto 0); -- Fraction shifted
|
|
variable shift : INTEGER;
|
|
variable result_big : UNRESOLVED_ufixed (left_index downto right_index-3);
|
|
variable result : UNRESOLVED_ufixed (left_index downto right_index); -- result
|
|
begin -- function to_ufixed
|
|
validfp := Classfp (arg, check_error);
|
|
classcase : case validfp is
|
|
when isx | nan | quiet_nan =>
|
|
frac := (others => 'X');
|
|
when pos_zero | neg_inf | neg_zero | neg_normal | neg_denormal =>
|
|
frac := (others => '0'); -- return 0
|
|
when pos_inf =>
|
|
frac := (others => '1'); -- always saturate
|
|
when others =>
|
|
expon_base := 2**(exponent_width-1) -1; -- exponent offset
|
|
-- Figure out the fraction
|
|
if (validfp = pos_denormal) and denormalize then
|
|
exp := -expon_base +1;
|
|
frac (frac'high) := '0'; -- Remove the "1.0".
|
|
else
|
|
-- exponent /= '0', normal floating point
|
|
expon := UNSIGNED(arg (exponent_width-1 downto 0));
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
exp := to_integer (SIGNED(expon)) +1;
|
|
frac (frac'high) := '1'; -- Add the "1.0".
|
|
end if;
|
|
shift := (frac'high - 3 + right_index) - exp;
|
|
if fraction_width > frac'high then -- Can only use size-2 bits
|
|
frac (frac'high-1 downto 0) := UNSIGNED (to_slv (arg(-1 downto
|
|
-frac'high)));
|
|
else -- can use all bits
|
|
frac (frac'high-1 downto frac'high-fraction_width) :=
|
|
UNSIGNED (to_slv (arg(-1 downto -fraction_width)));
|
|
end if;
|
|
frac_shift := frac srl shift;
|
|
if shift < 0 then -- Overflow
|
|
frac := (others => '1');
|
|
else
|
|
frac := frac_shift;
|
|
end if;
|
|
end case classcase;
|
|
result_big := to_ufixed (
|
|
arg => STD_ULOGIC_VECTOR(frac),
|
|
left_index => left_index,
|
|
right_index => (right_index-3));
|
|
result := resize (arg => result_big,
|
|
left_index => left_index,
|
|
right_index => right_index,
|
|
round_style => round_style,
|
|
overflow_style => overflow_style);
|
|
return result;
|
|
end function to_ufixed;
|
|
|
|
-- purpose: Converts a float to sfixed
|
|
function to_sfixed (
|
|
arg : UNRESOLVED_float; -- fp input
|
|
constant left_index : INTEGER; -- integer part
|
|
constant right_index : INTEGER; -- fraction part
|
|
constant overflow_style : fixed_overflow_style_type := fixed_overflow_style; -- saturate
|
|
constant round_style : fixed_round_style_type := fixed_round_style; -- rounding
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return UNRESOLVED_sfixed
|
|
is
|
|
constant fraction_width : INTEGER := -mine(arg'low, arg'low); -- length of FP output fraction
|
|
constant exponent_width : INTEGER := arg'high; -- length of FP output exponent
|
|
constant size : INTEGER := left_index - right_index + 4; -- unsigned size
|
|
variable expon_base : INTEGER; -- exponent offset
|
|
variable validfp : valid_fpstate; -- Valid FP state
|
|
variable exp : INTEGER; -- Exponent
|
|
variable sign : BOOLEAN; -- true if negative
|
|
variable expon : UNSIGNED (exponent_width-1 downto 0); -- Vectorized exponent
|
|
-- Base to divide fraction by
|
|
variable frac : UNSIGNED (size-2 downto 0) := (others => '0'); -- Fraction
|
|
variable frac_shift : UNSIGNED (size-2 downto 0); -- Fraction shifted
|
|
variable shift : INTEGER;
|
|
variable rsigned : SIGNED (size-1 downto 0); -- signed version of result
|
|
variable result_big : UNRESOLVED_sfixed (left_index downto right_index-3);
|
|
variable result : UNRESOLVED_sfixed (left_index downto right_index)
|
|
:= (others => '0'); -- result
|
|
begin -- function to_sfixed
|
|
validfp := Classfp (arg, check_error);
|
|
classcase : case validfp is
|
|
when isx | nan | quiet_nan =>
|
|
result := (others => 'X');
|
|
when pos_zero | neg_zero =>
|
|
result := (others => '0'); -- return 0
|
|
when neg_inf =>
|
|
result (left_index) := '1'; -- return smallest negative number
|
|
when pos_inf =>
|
|
result := (others => '1'); -- return largest number
|
|
result (left_index) := '0';
|
|
when others =>
|
|
expon_base := 2**(exponent_width-1) -1; -- exponent offset
|
|
if arg(exponent_width) = '0' then
|
|
sign := false;
|
|
else
|
|
sign := true;
|
|
end if;
|
|
-- Figure out the fraction
|
|
if (validfp = pos_denormal or validfp = neg_denormal)
|
|
and denormalize then
|
|
exp := -expon_base +1;
|
|
frac (frac'high) := '0'; -- Add the "1.0".
|
|
else
|
|
-- exponent /= '0', normal floating point
|
|
expon := UNSIGNED(arg (exponent_width-1 downto 0));
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
exp := to_integer (SIGNED(expon)) +1;
|
|
frac (frac'high) := '1'; -- Add the "1.0".
|
|
end if;
|
|
shift := (frac'high - 3 + right_index) - exp;
|
|
if fraction_width > frac'high then -- Can only use size-2 bits
|
|
frac (frac'high-1 downto 0) := UNSIGNED (to_slv (arg(-1 downto
|
|
-frac'high)));
|
|
else -- can use all bits
|
|
frac (frac'high-1 downto frac'high-fraction_width) :=
|
|
UNSIGNED (to_slv (arg(-1 downto -fraction_width)));
|
|
end if;
|
|
frac_shift := frac srl shift;
|
|
if shift < 0 then -- Overflow
|
|
frac := (others => '1');
|
|
else
|
|
frac := frac_shift;
|
|
end if;
|
|
if not sign then
|
|
rsigned := SIGNED("0" & frac);
|
|
else
|
|
rsigned := -(SIGNED("0" & frac));
|
|
end if;
|
|
result_big := to_sfixed (
|
|
arg => STD_LOGIC_VECTOR(rsigned),
|
|
left_index => left_index,
|
|
right_index => (right_index-3));
|
|
result := resize (arg => result_big,
|
|
left_index => left_index,
|
|
right_index => right_index,
|
|
round_style => round_style,
|
|
overflow_style => overflow_style);
|
|
end case classcase;
|
|
return result;
|
|
end function to_sfixed;
|
|
|
|
-- size_res versions
|
|
-- float to unsigned
|
|
function to_unsigned (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
size_res : UNRESOLVED_UNSIGNED;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error) -- check for errors
|
|
return UNRESOLVED_UNSIGNED
|
|
is
|
|
variable result : UNRESOLVED_UNSIGNED (size_res'range);
|
|
begin
|
|
if (size_res'length = 0) then
|
|
return result;
|
|
else
|
|
result := to_unsigned (
|
|
arg => arg,
|
|
size => size_res'length,
|
|
round_style => round_style,
|
|
check_error => check_error);
|
|
return result;
|
|
end if;
|
|
end function to_unsigned;
|
|
|
|
-- float to signed
|
|
function to_signed (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
size_res : UNRESOLVED_SIGNED;
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error) -- check for errors
|
|
return UNRESOLVED_SIGNED
|
|
is
|
|
variable result : UNRESOLVED_SIGNED (size_res'range);
|
|
begin
|
|
if (size_res'length = 0) then
|
|
return result;
|
|
else
|
|
result := to_signed (
|
|
arg => arg,
|
|
size => size_res'length,
|
|
round_style => round_style,
|
|
check_error => check_error);
|
|
return result;
|
|
end if;
|
|
end function to_signed;
|
|
|
|
-- purpose: Converts a float to unsigned fixed point
|
|
function to_ufixed (
|
|
arg : UNRESOLVED_float; -- fp input
|
|
size_res : UNRESOLVED_ufixed;
|
|
constant overflow_style : fixed_overflow_style_type := fixed_overflow_style; -- saturate
|
|
constant round_style : fixed_round_style_type := fixed_round_style; -- rounding
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return UNRESOLVED_ufixed
|
|
is
|
|
variable result : UNRESOLVED_ufixed (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_ufixed (
|
|
arg => arg,
|
|
left_index => size_res'high,
|
|
right_index => size_res'low,
|
|
overflow_style => overflow_style,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end if;
|
|
end function to_ufixed;
|
|
|
|
-- float to signed fixed point
|
|
function to_sfixed (
|
|
arg : UNRESOLVED_float; -- fp input
|
|
size_res : UNRESOLVED_sfixed;
|
|
constant overflow_style : fixed_overflow_style_type := fixed_overflow_style; -- saturate
|
|
constant round_style : fixed_round_style_type := fixed_round_style; -- rounding
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return UNRESOLVED_sfixed
|
|
is
|
|
variable result : UNRESOLVED_sfixed (size_res'left downto size_res'right);
|
|
begin
|
|
if (result'length < 1) then
|
|
return result;
|
|
else
|
|
result := to_sfixed (
|
|
arg => arg,
|
|
left_index => size_res'high,
|
|
right_index => size_res'low,
|
|
overflow_style => overflow_style,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize => denormalize);
|
|
return result;
|
|
end if;
|
|
end function to_sfixed;
|
|
|
|
-- to_real (float)
|
|
-- typically not Synthesizable unless the input is a constant.
|
|
function to_real (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return REAL
|
|
is
|
|
constant fraction_width : INTEGER := -mine(arg'low, arg'low); -- length of FP output fraction
|
|
constant exponent_width : INTEGER := arg'high; -- length of FP output exponent
|
|
variable sign : REAL; -- Sign, + or - 1
|
|
variable exp : INTEGER; -- Exponent
|
|
variable expon_base : INTEGER; -- exponent offset
|
|
variable frac : REAL := 0.0; -- Fraction
|
|
variable validfp : valid_fpstate; -- Valid FP state
|
|
variable expon : UNSIGNED (exponent_width - 1 downto 0)
|
|
:= (others => '1'); -- Vectorized exponent
|
|
begin
|
|
validfp := Classfp (arg, check_error);
|
|
classcase : case validfp is
|
|
when isx | pos_zero | neg_zero | nan | quiet_nan =>
|
|
return 0.0;
|
|
when neg_inf =>
|
|
return REAL'low; -- Negative infinity.
|
|
when pos_inf =>
|
|
return REAL'high; -- Positive infinity
|
|
when others =>
|
|
expon_base := 2**(exponent_width-1) -1;
|
|
if to_X01(arg(exponent_width)) = '0' then
|
|
sign := 1.0;
|
|
else
|
|
sign := -1.0;
|
|
end if;
|
|
-- Figure out the fraction
|
|
for i in 0 to fraction_width-1 loop
|
|
if to_X01(arg (-1 - i)) = '1' then
|
|
frac := frac + (2.0 **(-1 - i));
|
|
end if;
|
|
end loop; -- i
|
|
if validfp = pos_normal or validfp = neg_normal or not denormalize then
|
|
-- exponent /= '0', normal floating point
|
|
expon := UNSIGNED(arg (exponent_width-1 downto 0));
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
exp := to_integer (SIGNED(expon)) +1;
|
|
sign := sign * (2.0 ** exp) * (1.0 + frac);
|
|
else -- exponent = '0', IEEE extended floating point
|
|
exp := 1 - expon_base;
|
|
sign := sign * (2.0 ** exp) * frac;
|
|
end if;
|
|
return sign;
|
|
end case classcase;
|
|
end function to_real;
|
|
|
|
-- For Verilog compatability
|
|
function realtobits (arg : REAL) return STD_ULOGIC_VECTOR is
|
|
variable result : float64; -- 64 bit floating point
|
|
begin
|
|
result := to_float (arg => arg,
|
|
exponent_width => float64'high,
|
|
fraction_width => -float64'low);
|
|
return to_sulv (result);
|
|
end function realtobits;
|
|
|
|
function bitstoreal (arg : STD_ULOGIC_VECTOR) return REAL is
|
|
variable arg64 : float64; -- arg converted to float
|
|
begin
|
|
arg64 := to_float (arg => arg,
|
|
exponent_width => float64'high,
|
|
fraction_width => -float64'low);
|
|
return to_real (arg64);
|
|
end function bitstoreal;
|
|
|
|
-- purpose: Removes meta-logical values from FP string
|
|
function to_01 (
|
|
arg : UNRESOLVED_float; -- floating point input
|
|
XMAP : STD_LOGIC := '0')
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (arg'range);
|
|
begin -- function to_01
|
|
if (arg'length < 1) then
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& "TO_01: null detected, returning NULL"
|
|
severity warning;
|
|
return NAFP;
|
|
end if;
|
|
result := UNRESOLVED_float (STD_LOGIC_VECTOR(to_01(UNSIGNED(to_slv(arg)), XMAP)));
|
|
return result;
|
|
end function to_01;
|
|
|
|
function Is_X
|
|
(arg : UNRESOLVED_float)
|
|
return BOOLEAN is
|
|
begin
|
|
return Is_X (to_slv(arg));
|
|
end function Is_X;
|
|
|
|
function to_X01 (arg : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable result : UNRESOLVED_float (arg'range);
|
|
begin
|
|
if (arg'length < 1) then
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& "TO_X01: null detected, returning NULL"
|
|
severity warning;
|
|
return NAFP;
|
|
else
|
|
result := UNRESOLVED_float (to_X01(to_slv(arg)));
|
|
return result;
|
|
end if;
|
|
end function to_X01;
|
|
|
|
function to_X01Z (arg : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable result : UNRESOLVED_float (arg'range);
|
|
begin
|
|
if (arg'length < 1) then
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& "TO_X01Z: null detected, returning NULL"
|
|
severity warning;
|
|
return NAFP;
|
|
else
|
|
result := UNRESOLVED_float (to_X01Z(to_slv(arg)));
|
|
return result;
|
|
end if;
|
|
end function to_X01Z;
|
|
|
|
function to_UX01 (arg : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable result : UNRESOLVED_float (arg'range);
|
|
begin
|
|
if (arg'length < 1) then
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& "TO_UX01: null detected, returning NULL"
|
|
severity warning;
|
|
return NAFP;
|
|
else
|
|
result := UNRESOLVED_float (to_UX01(to_slv(arg)));
|
|
return result;
|
|
end if;
|
|
end function to_UX01;
|
|
|
|
-- These allows the base math functions to use the default values
|
|
-- of their parameters. Thus they do full IEEE floating point.
|
|
function "+" (l, r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
begin
|
|
return add (l, r);
|
|
end function "+";
|
|
|
|
function "-" (l, r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
begin
|
|
return subtract (l, r);
|
|
end function "-";
|
|
|
|
function "*" (l, r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
begin
|
|
return multiply (l, r);
|
|
end function "*";
|
|
|
|
function "/" (l, r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
begin
|
|
return divide (l, r);
|
|
end function "/";
|
|
|
|
function "rem" (l, r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
begin
|
|
return remainder (l, r);
|
|
end function "rem";
|
|
|
|
function "mod" (l, r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
begin
|
|
return modulo (l, r);
|
|
end function "mod";
|
|
|
|
-- overloaded versions
|
|
function "+" (l : UNRESOLVED_float; r : REAL) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return add (l, r_float);
|
|
end function "+";
|
|
|
|
function "+" (l : REAL; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return add (l_float, r);
|
|
end function "+";
|
|
|
|
function "+" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return add (l, r_float);
|
|
end function "+";
|
|
|
|
function "+" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return add (l_float, r);
|
|
end function "+";
|
|
|
|
function "-" (l : UNRESOLVED_float; r : REAL) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return subtract (l, r_float);
|
|
end function "-";
|
|
|
|
function "-" (l : REAL; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return subtract (l_float, r);
|
|
end function "-";
|
|
|
|
function "-" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return subtract (l, r_float);
|
|
end function "-";
|
|
|
|
function "-" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return subtract (l_float, r);
|
|
end function "-";
|
|
|
|
function "*" (l : UNRESOLVED_float; r : REAL) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return multiply (l, r_float);
|
|
end function "*";
|
|
|
|
function "*" (l : REAL; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return multiply (l_float, r);
|
|
end function "*";
|
|
|
|
function "*" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return multiply (l, r_float);
|
|
end function "*";
|
|
|
|
function "*" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return multiply (l_float, r);
|
|
end function "*";
|
|
|
|
function "/" (l : UNRESOLVED_float; r : REAL) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return divide (l, r_float);
|
|
end function "/";
|
|
|
|
function "/" (l : REAL; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return divide (l_float, r);
|
|
end function "/";
|
|
|
|
function "/" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return divide (l, r_float);
|
|
end function "/";
|
|
|
|
function "/" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return divide (l_float, r);
|
|
end function "/";
|
|
|
|
function "rem" (l : UNRESOLVED_float; r : REAL) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return remainder (l, r_float);
|
|
end function "rem";
|
|
|
|
function "rem" (l : REAL; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return remainder (l_float, r);
|
|
end function "rem";
|
|
|
|
function "rem" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return remainder (l, r_float);
|
|
end function "rem";
|
|
|
|
function "rem" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return remainder (l_float, r);
|
|
end function "rem";
|
|
|
|
function "mod" (l : UNRESOLVED_float; r : REAL) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return modulo (l, r_float);
|
|
end function "mod";
|
|
|
|
function "mod" (l : REAL; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return modulo (l_float, r);
|
|
end function "mod";
|
|
|
|
function "mod" (l : UNRESOLVED_float; r : INTEGER) return UNRESOLVED_float is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return modulo (l, r_float);
|
|
end function "mod";
|
|
|
|
function "mod" (l : INTEGER; r : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return modulo (l_float, r);
|
|
end function "mod";
|
|
|
|
function "=" (l : UNRESOLVED_float; r : REAL) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return eq (l, r_float);
|
|
end function "=";
|
|
|
|
function "/=" (l : UNRESOLVED_float; r : REAL) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return ne (l, r_float);
|
|
end function "/=";
|
|
|
|
function ">=" (l : UNRESOLVED_float; r : REAL) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return ge (l, r_float);
|
|
end function ">=";
|
|
|
|
function "<=" (l : UNRESOLVED_float; r : REAL) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return le (l, r_float);
|
|
end function "<=";
|
|
|
|
function ">" (l : UNRESOLVED_float; r : REAL) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return gt (l, r_float);
|
|
end function ">";
|
|
|
|
function "<" (l : UNRESOLVED_float; r : REAL) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return lt (l, r_float);
|
|
end function "<";
|
|
|
|
function "=" (l : REAL; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return eq (l_float, r);
|
|
end function "=";
|
|
|
|
function "/=" (l : REAL; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return ne (l_float, r);
|
|
end function "/=";
|
|
|
|
function ">=" (l : REAL; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return ge (l_float, r);
|
|
end function ">=";
|
|
|
|
function "<=" (l : REAL; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return le (l_float, r);
|
|
end function "<=";
|
|
|
|
function ">" (l : REAL; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return gt (l_float, r);
|
|
end function ">";
|
|
|
|
function "<" (l : REAL; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return lt (l_float, r);
|
|
end function "<";
|
|
|
|
function "=" (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return eq (l, r_float);
|
|
end function "=";
|
|
|
|
function "/=" (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return ne (l, r_float);
|
|
end function "/=";
|
|
|
|
function ">=" (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return ge (l, r_float);
|
|
end function ">=";
|
|
|
|
function "<=" (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return le (l, r_float);
|
|
end function "<=";
|
|
|
|
function ">" (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return gt (l, r_float);
|
|
end function ">";
|
|
|
|
function "<" (l : UNRESOLVED_float; r : INTEGER) return BOOLEAN is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return lt (l, r_float);
|
|
end function "<";
|
|
|
|
function "=" (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return eq (l_float, r);
|
|
end function "=";
|
|
|
|
function "/=" (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return ne (l_float, r);
|
|
end function "/=";
|
|
|
|
function ">=" (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return ge (l_float, r);
|
|
end function ">=";
|
|
|
|
function "<=" (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return le (l_float, r);
|
|
end function "<=";
|
|
|
|
function ">" (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return gt (l_float, r);
|
|
end function ">";
|
|
|
|
function "<" (l : INTEGER; r : UNRESOLVED_float) return BOOLEAN is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float(l, r'high, -r'low);
|
|
return lt (l_float, r);
|
|
end function "<";
|
|
|
|
-- ?= overloads
|
|
function "?=" (l : UNRESOLVED_float; r : REAL) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?= r_float;
|
|
end function "?=";
|
|
|
|
function "?/=" (l : UNRESOLVED_float; r : REAL) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?/= r_float;
|
|
end function "?/=";
|
|
|
|
function "?>" (l : UNRESOLVED_float; r : REAL) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?> r_float;
|
|
end function "?>";
|
|
|
|
function "?>=" (l : UNRESOLVED_float; r : REAL) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?>= r_float;
|
|
end function "?>=";
|
|
|
|
function "?<" (l : UNRESOLVED_float; r : REAL) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?< r_float;
|
|
end function "?<";
|
|
|
|
function "?<=" (l : UNRESOLVED_float; r : REAL) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?<= r_float;
|
|
end function "?<=";
|
|
|
|
-- real and float
|
|
function "?=" (l : REAL; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?= r;
|
|
end function "?=";
|
|
|
|
function "?/=" (l : REAL; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?/= r;
|
|
end function "?/=";
|
|
|
|
function "?>" (l : REAL; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?> r;
|
|
end function "?>";
|
|
|
|
function "?>=" (l : REAL; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?>= r;
|
|
end function "?>=";
|
|
|
|
function "?<" (l : REAL; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?< r;
|
|
end function "?<";
|
|
|
|
function "?<=" (l : REAL; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?<= r;
|
|
end function "?<=";
|
|
|
|
-- ?= overloads
|
|
function "?=" (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?= r_float;
|
|
end function "?=";
|
|
|
|
function "?/=" (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?/= r_float;
|
|
end function "?/=";
|
|
|
|
function "?>" (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?> r_float;
|
|
end function "?>";
|
|
|
|
function "?>=" (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?>= r_float;
|
|
end function "?>=";
|
|
|
|
function "?<" (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?< r_float;
|
|
end function "?<";
|
|
|
|
function "?<=" (l : UNRESOLVED_float; r : INTEGER) return STD_ULOGIC is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return l ?<= r_float;
|
|
end function "?<=";
|
|
|
|
-- integer and float
|
|
function "?=" (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?= r;
|
|
end function "?=";
|
|
|
|
function "?/=" (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?/= r;
|
|
end function "?/=";
|
|
|
|
function "?>" (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?> r;
|
|
end function "?>";
|
|
|
|
function "?>=" (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?>= r;
|
|
end function "?>=";
|
|
|
|
function "?<" (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?< r;
|
|
end function "?<";
|
|
|
|
function "?<=" (l : INTEGER; r : UNRESOLVED_float) return STD_ULOGIC is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return l_float ?<= r;
|
|
end function "?<=";
|
|
|
|
-- minimum and maximum overloads
|
|
function minimum (l : UNRESOLVED_float; r : REAL)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return minimum (l, r_float);
|
|
end function minimum;
|
|
|
|
function maximum (l : UNRESOLVED_float; r : REAL)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return maximum (l, r_float);
|
|
end function maximum;
|
|
|
|
function minimum (l : REAL; r : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return minimum (l_float, r);
|
|
end function minimum;
|
|
|
|
function maximum (l : REAL; r : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return maximum (l_float, r);
|
|
end function maximum;
|
|
|
|
function minimum (l : UNRESOLVED_float; r : INTEGER)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return minimum (l, r_float);
|
|
end function minimum;
|
|
|
|
function maximum (l : UNRESOLVED_float; r : INTEGER)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable r_float : UNRESOLVED_float (l'range);
|
|
begin
|
|
r_float := to_float (r, l'high, -l'low);
|
|
return maximum (l, r_float);
|
|
end function maximum;
|
|
|
|
function minimum (l : INTEGER; r : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return minimum (l_float, r);
|
|
end function minimum;
|
|
|
|
function maximum (l : INTEGER; r : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable l_float : UNRESOLVED_float (r'range);
|
|
begin
|
|
l_float := to_float (l, r'high, -r'low);
|
|
return maximum (l_float, r);
|
|
end function maximum;
|
|
|
|
----------------------------------------------------------------------------
|
|
-- logical functions
|
|
----------------------------------------------------------------------------
|
|
function "not" (L : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
RESULT := not to_sulv(L);
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "not";
|
|
|
|
function "and" (L, R : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
RESULT := to_sulv(L) and to_sulv(R);
|
|
else
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& """and"": Range error L'RANGE /= R'RANGE"
|
|
severity warning;
|
|
RESULT := (others => 'X');
|
|
end if;
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "and";
|
|
|
|
function "or" (L, R : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
RESULT := to_sulv(L) or to_sulv(R);
|
|
else
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& """or"": Range error L'RANGE /= R'RANGE"
|
|
severity warning;
|
|
RESULT := (others => 'X');
|
|
end if;
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "or";
|
|
|
|
function "nand" (L, R : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
RESULT := to_sulv(L) nand to_sulv(R);
|
|
else
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& """nand"": Range error L'RANGE /= R'RANGE"
|
|
severity warning;
|
|
RESULT := (others => 'X');
|
|
end if;
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "nand";
|
|
|
|
function "nor" (L, R : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
RESULT := to_sulv(L) nor to_sulv(R);
|
|
else
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& """nor"": Range error L'RANGE /= R'RANGE"
|
|
severity warning;
|
|
RESULT := (others => 'X');
|
|
end if;
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "nor";
|
|
|
|
function "xor" (L, R : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
RESULT := to_sulv(L) xor to_sulv(R);
|
|
else
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& """xor"": Range error L'RANGE /= R'RANGE"
|
|
severity warning;
|
|
RESULT := (others => 'X');
|
|
end if;
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "xor";
|
|
|
|
function "xnor" (L, R : UNRESOLVED_float) return UNRESOLVED_float is
|
|
variable RESULT : STD_ULOGIC_VECTOR(L'length-1 downto 0); -- force downto
|
|
begin
|
|
if (L'high = R'high and L'low = R'low) then
|
|
RESULT := to_sulv(L) xnor to_sulv(R);
|
|
else
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& """xnor"": Range error L'RANGE /= R'RANGE"
|
|
severity warning;
|
|
RESULT := (others => 'X');
|
|
end if;
|
|
return to_float (RESULT, L'high, -L'low);
|
|
end function "xnor";
|
|
|
|
-- Vector and std_ulogic functions, same as functions in numeric_std
|
|
function "and" (L : STD_ULOGIC; R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (R'range);
|
|
begin
|
|
result := UNRESOLVED_float (L and to_sulv(R));
|
|
return result;
|
|
end function "and";
|
|
|
|
function "and" (L : UNRESOLVED_float; R : STD_ULOGIC)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (L'range);
|
|
begin
|
|
result := UNRESOLVED_float (to_sulv(L) and R);
|
|
return result;
|
|
end function "and";
|
|
|
|
function "or" (L : STD_ULOGIC; R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (R'range);
|
|
begin
|
|
result := UNRESOLVED_float (L or to_sulv(R));
|
|
return result;
|
|
end function "or";
|
|
|
|
function "or" (L : UNRESOLVED_float; R : STD_ULOGIC)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (L'range);
|
|
begin
|
|
result := UNRESOLVED_float (to_sulv(L) or R);
|
|
return result;
|
|
end function "or";
|
|
|
|
function "nand" (L : STD_ULOGIC; R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (R'range);
|
|
begin
|
|
result := UNRESOLVED_float (L nand to_sulv(R));
|
|
return result;
|
|
end function "nand";
|
|
|
|
function "nand" (L : UNRESOLVED_float; R : STD_ULOGIC)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (L'range);
|
|
begin
|
|
result := UNRESOLVED_float (to_sulv(L) nand R);
|
|
return result;
|
|
end function "nand";
|
|
|
|
function "nor" (L : STD_ULOGIC; R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (R'range);
|
|
begin
|
|
result := UNRESOLVED_float (L nor to_sulv(R));
|
|
return result;
|
|
end function "nor";
|
|
|
|
function "nor" (L : UNRESOLVED_float; R : STD_ULOGIC)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (L'range);
|
|
begin
|
|
result := UNRESOLVED_float (to_sulv(L) nor R);
|
|
return result;
|
|
end function "nor";
|
|
|
|
function "xor" (L : STD_ULOGIC; R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (R'range);
|
|
begin
|
|
result := UNRESOLVED_float (L xor to_sulv(R));
|
|
return result;
|
|
end function "xor";
|
|
|
|
function "xor" (L : UNRESOLVED_float; R : STD_ULOGIC)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (L'range);
|
|
begin
|
|
result := UNRESOLVED_float (to_sulv(L) xor R);
|
|
return result;
|
|
end function "xor";
|
|
|
|
function "xnor" (L : STD_ULOGIC; R : UNRESOLVED_float)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (R'range);
|
|
begin
|
|
result := UNRESOLVED_float (L xnor to_sulv(R));
|
|
return result;
|
|
end function "xnor";
|
|
|
|
function "xnor" (L : UNRESOLVED_float; R : STD_ULOGIC)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (L'range);
|
|
begin
|
|
result := UNRESOLVED_float (to_sulv(L) xnor R);
|
|
return result;
|
|
end function "xnor";
|
|
|
|
-- Reduction operators, same as numeric_std functions
|
|
|
|
function "and" (l : UNRESOLVED_float) return STD_ULOGIC is
|
|
begin
|
|
return and to_sulv(l);
|
|
end function "and";
|
|
|
|
function "nand" (l : UNRESOLVED_float) return STD_ULOGIC is
|
|
begin
|
|
return nand to_sulv(l);
|
|
end function "nand";
|
|
|
|
function "or" (l : UNRESOLVED_float) return STD_ULOGIC is
|
|
begin
|
|
return or to_sulv(l);
|
|
end function "or";
|
|
|
|
function "nor" (l : UNRESOLVED_float) return STD_ULOGIC is
|
|
begin
|
|
return nor to_sulv(l);
|
|
end function "nor";
|
|
|
|
function "xor" (l : UNRESOLVED_float) return STD_ULOGIC is
|
|
begin
|
|
return xor to_sulv(l);
|
|
end function "xor";
|
|
|
|
function "xnor" (l : UNRESOLVED_float) return STD_ULOGIC is
|
|
begin
|
|
return xnor to_sulv(l);
|
|
end function "xnor";
|
|
|
|
-----------------------------------------------------------------------------
|
|
-- Recommended Functions from the IEEE 754 Appendix
|
|
-----------------------------------------------------------------------------
|
|
-- returns x with the sign of y.
|
|
function Copysign (
|
|
x, y : UNRESOLVED_float) -- floating point input
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return y(y'high) & x (x'high-1 downto x'low);
|
|
end function Copysign;
|
|
|
|
-- Returns y * 2**n for integral values of N without computing 2**n
|
|
function Scalb (
|
|
y : UNRESOLVED_float; -- floating point input
|
|
N : INTEGER; -- exponent to add
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(y'low, y'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := y'high; -- length of FP output exponent
|
|
variable arg, result : UNRESOLVED_float (exponent_width downto -fraction_width); -- internal argument
|
|
variable expon : SIGNED (exponent_width-1 downto 0); -- Vectorized exp
|
|
variable exp : SIGNED (exponent_width downto 0);
|
|
variable ufract : UNSIGNED (fraction_width downto 0);
|
|
variable fptype : valid_fpstate;
|
|
begin
|
|
-- This can be done by simply adding N to the exponent.
|
|
arg := to_01 (y, 'X');
|
|
fptype := Classfp(arg, check_error);
|
|
classcase : case fptype is
|
|
when isx =>
|
|
result := (others => 'X');
|
|
when nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
result := qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
when others =>
|
|
break_number (
|
|
arg => arg,
|
|
fptyp => fptype,
|
|
denormalize => denormalize,
|
|
fract => ufract,
|
|
expon => expon);
|
|
exp := resize (expon, exp'length) + N;
|
|
result := normalize (
|
|
fract => ufract,
|
|
expon => exp,
|
|
sign => to_x01 (arg (arg'high)),
|
|
fraction_width => fraction_width,
|
|
exponent_width => exponent_width,
|
|
round_style => round_style,
|
|
denormalize => denormalize,
|
|
nguard => 0);
|
|
end case classcase;
|
|
return result;
|
|
end function Scalb;
|
|
|
|
-- Returns y * 2**n for integral values of N without computing 2**n
|
|
function Scalb (
|
|
y : UNRESOLVED_float; -- floating point input
|
|
N : UNRESOLVED_SIGNED; -- exponent to add
|
|
constant round_style : round_type := float_round_style; -- rounding option
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize) -- Use IEEE extended FP
|
|
return UNRESOLVED_float
|
|
is
|
|
variable n_int : INTEGER;
|
|
begin
|
|
n_int := to_integer(N);
|
|
return Scalb (y => y,
|
|
N => n_int,
|
|
round_style => round_style,
|
|
check_error => check_error,
|
|
denormalize => denormalize);
|
|
end function Scalb;
|
|
|
|
-- returns the unbiased exponent of x
|
|
function Logb (
|
|
x : UNRESOLVED_float) -- floating point input
|
|
return INTEGER
|
|
is
|
|
constant fraction_width : NATURAL := -mine (x'low, x'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := x'high; -- length of FP output exponent
|
|
variable result : INTEGER; -- result
|
|
variable arg : UNRESOLVED_float (exponent_width downto -fraction_width); -- internal argument
|
|
variable expon : SIGNED (exponent_width - 1 downto 0);
|
|
variable fract : UNSIGNED (fraction_width downto 0);
|
|
constant expon_base : INTEGER := 2**(exponent_width-1) -1; -- exponent
|
|
-- offset +1
|
|
variable fptype : valid_fpstate;
|
|
begin
|
|
-- Just return the exponent.
|
|
arg := to_01 (x, 'X');
|
|
fptype := Classfp(arg);
|
|
classcase : case fptype is
|
|
when isx | nan | quiet_nan =>
|
|
-- Return quiet NAN, IEEE754-1985-7.1,1
|
|
result := 0;
|
|
when pos_denormal | neg_denormal =>
|
|
fract (fraction_width) := '0';
|
|
fract (fraction_width-1 downto 0) :=
|
|
UNSIGNED (to_slv(arg(-1 downto -fraction_width)));
|
|
result := find_leftmost (fract, '1') -- Find the first "1"
|
|
- fraction_width; -- subtract the length we want
|
|
result := -expon_base + 1 + result;
|
|
when others =>
|
|
expon := SIGNED(arg (exponent_width - 1 downto 0));
|
|
expon(exponent_width-1) := not expon(exponent_width-1);
|
|
expon := expon + 1;
|
|
result := to_integer (expon);
|
|
end case classcase;
|
|
return result;
|
|
end function Logb;
|
|
|
|
-- returns the unbiased exponent of x
|
|
function Logb (
|
|
x : UNRESOLVED_float) -- floating point input
|
|
return UNRESOLVED_SIGNED
|
|
is
|
|
constant exponent_width : NATURAL := x'high; -- length of FP output exponent
|
|
variable result : SIGNED (exponent_width - 1 downto 0); -- result
|
|
begin
|
|
-- Just return the exponent.
|
|
result := to_signed (Logb (x), exponent_width);
|
|
return result;
|
|
end function Logb;
|
|
|
|
-- returns the next representable neighbor of x in the direction toward y
|
|
function Nextafter (
|
|
x, y : UNRESOLVED_float; -- floating point input
|
|
constant check_error : BOOLEAN := float_check_error; -- check for errors
|
|
constant denormalize : BOOLEAN := float_denormalize)
|
|
return UNRESOLVED_float
|
|
is
|
|
constant fraction_width : NATURAL := -mine(x'low, x'low); -- length of FP output fraction
|
|
constant exponent_width : NATURAL := x'high; -- length of FP output exponent
|
|
function "=" (
|
|
l, r : UNRESOLVED_float) -- inputs
|
|
return BOOLEAN is
|
|
begin -- function "="
|
|
return eq (l => l,
|
|
r => r,
|
|
check_error => false);
|
|
end function "=";
|
|
function ">" (
|
|
l, r : UNRESOLVED_float) -- inputs
|
|
return BOOLEAN is
|
|
begin -- function ">"
|
|
return gt (l => l,
|
|
r => r,
|
|
check_error => false);
|
|
end function ">";
|
|
variable fract : UNSIGNED (fraction_width-1 downto 0);
|
|
variable expon : UNSIGNED (exponent_width-1 downto 0);
|
|
variable sign : STD_ULOGIC;
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable validfpx, validfpy : valid_fpstate; -- Valid FP state
|
|
begin -- fp_Nextafter
|
|
-- If Y > X, add one to the fraction, otherwise subtract.
|
|
validfpx := Classfp (x, check_error);
|
|
validfpy := Classfp (y, check_error);
|
|
if validfpx = isx or validfpy = isx then
|
|
result := (others => 'X');
|
|
return result;
|
|
elsif (validfpx = nan or validfpy = nan) then
|
|
return nanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif (validfpx = quiet_nan or validfpy = quiet_nan) then
|
|
return qnanfp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
elsif x = y then -- Return X
|
|
return x;
|
|
else
|
|
fract := UNSIGNED (to_slv (x (-1 downto -fraction_width))); -- Fraction
|
|
expon := UNSIGNED (x (exponent_width - 1 downto 0)); -- exponent
|
|
sign := x(exponent_width); -- sign bit
|
|
if (y > x) then
|
|
-- Increase the number given
|
|
if validfpx = neg_inf then
|
|
-- return most negative number
|
|
expon := (others => '1');
|
|
expon (0) := '0';
|
|
fract := (others => '1');
|
|
elsif validfpx = pos_zero or validfpx = neg_zero then
|
|
-- return smallest denormal number
|
|
sign := '0';
|
|
expon := (others => '0');
|
|
fract := (others => '0');
|
|
fract(0) := '1';
|
|
elsif validfpx = pos_normal then
|
|
if and (fract) = '1' then -- fraction is all "1".
|
|
if and (expon (exponent_width-1 downto 1)) = '1'
|
|
and expon (0) = '0' then
|
|
-- Exponent is one away from infinity.
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& "FP_NEXTAFTER: NextAfter overflow"
|
|
severity warning;
|
|
return pos_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
expon := expon + 1;
|
|
fract := (others => '0');
|
|
end if;
|
|
else
|
|
fract := fract + 1;
|
|
end if;
|
|
elsif validfpx = pos_denormal then
|
|
if and (fract) = '1' then -- fraction is all "1".
|
|
-- return smallest possible normal number
|
|
expon := (others => '0');
|
|
expon(0) := '1';
|
|
fract := (others => '0');
|
|
else
|
|
fract := fract + 1;
|
|
end if;
|
|
elsif validfpx = neg_normal then
|
|
if or (fract) = '0' then -- fraction is all "0".
|
|
if or (expon (exponent_width-1 downto 1)) = '0' and
|
|
expon (0) = '1' then -- Smallest exponent
|
|
-- return the largest negative denormal number
|
|
expon := (others => '0');
|
|
fract := (others => '1');
|
|
else
|
|
expon := expon - 1;
|
|
fract := (others => '1');
|
|
end if;
|
|
else
|
|
fract := fract - 1;
|
|
end if;
|
|
elsif validfpx = neg_denormal then
|
|
if or (fract(fract'high downto 1)) = '0'
|
|
and fract (0) = '1' then -- Smallest possible fraction
|
|
return zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
fract := fract - 1;
|
|
end if;
|
|
end if;
|
|
else
|
|
-- Decrease the number
|
|
if validfpx = pos_inf then
|
|
-- return most positive number
|
|
expon := (others => '1');
|
|
expon (0) := '0';
|
|
fract := (others => '1');
|
|
elsif validfpx = pos_zero
|
|
or Classfp (x) = neg_zero then
|
|
-- return smallest negative denormal number
|
|
sign := '1';
|
|
expon := (others => '0');
|
|
fract := (others => '0');
|
|
fract(0) := '1';
|
|
elsif validfpx = neg_normal then
|
|
if and (fract) = '1' then -- fraction is all "1".
|
|
if and (expon (exponent_width-1 downto 1)) = '1'
|
|
and expon (0) = '0' then
|
|
-- Exponent is one away from infinity.
|
|
assert no_warning
|
|
report float_generic_pkg'instance_name
|
|
& "FP_NEXTAFTER: NextAfter overflow"
|
|
severity warning;
|
|
return neg_inffp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
expon := expon + 1; -- Fraction overflow
|
|
fract := (others => '0');
|
|
end if;
|
|
else
|
|
fract := fract + 1;
|
|
end if;
|
|
elsif validfpx = neg_denormal then
|
|
if and (fract) = '1' then -- fraction is all "1".
|
|
-- return smallest possible normal number
|
|
expon := (others => '0');
|
|
expon(0) := '1';
|
|
fract := (others => '0');
|
|
else
|
|
fract := fract + 1;
|
|
end if;
|
|
elsif validfpx = pos_normal then
|
|
if or (fract) = '0' then -- fraction is all "0".
|
|
if or (expon (exponent_width-1 downto 1)) = '0' and
|
|
expon (0) = '1' then -- Smallest exponent
|
|
-- return the largest positive denormal number
|
|
expon := (others => '0');
|
|
fract := (others => '1');
|
|
else
|
|
expon := expon - 1;
|
|
fract := (others => '1');
|
|
end if;
|
|
else
|
|
fract := fract - 1;
|
|
end if;
|
|
elsif validfpx = pos_denormal then
|
|
if or (fract(fract'high downto 1)) = '0'
|
|
and fract (0) = '1' then -- Smallest possible fraction
|
|
return zerofp (fraction_width => fraction_width,
|
|
exponent_width => exponent_width);
|
|
else
|
|
fract := fract - 1;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
result (-1 downto -fraction_width) := UNRESOLVED_float(fract);
|
|
result (exponent_width -1 downto 0) := UNRESOLVED_float(expon);
|
|
result (exponent_width) := sign;
|
|
return result;
|
|
end if;
|
|
end function Nextafter;
|
|
|
|
-- Returns True if X is unordered with Y.
|
|
function Unordered (
|
|
x, y : UNRESOLVED_float) -- floating point input
|
|
return BOOLEAN
|
|
is
|
|
variable lfptype, rfptype : valid_fpstate;
|
|
begin
|
|
lfptype := Classfp (x);
|
|
rfptype := Classfp (y);
|
|
if (lfptype = nan or lfptype = quiet_nan or
|
|
rfptype = nan or rfptype = quiet_nan or
|
|
lfptype = isx or rfptype = isx) then
|
|
return true;
|
|
else
|
|
return false;
|
|
end if;
|
|
end function Unordered;
|
|
|
|
function Finite (
|
|
x : UNRESOLVED_float)
|
|
return BOOLEAN
|
|
is
|
|
variable fp_state : valid_fpstate; -- fp state
|
|
begin
|
|
fp_state := Classfp (x);
|
|
if (fp_state = pos_inf) or (fp_state = neg_inf) then
|
|
return true;
|
|
else
|
|
return false;
|
|
end if;
|
|
end function Finite;
|
|
|
|
function Isnan (
|
|
x : UNRESOLVED_float)
|
|
return BOOLEAN
|
|
is
|
|
variable fp_state : valid_fpstate; -- fp state
|
|
begin
|
|
fp_state := Classfp (x);
|
|
if (fp_state = nan) or (fp_state = quiet_nan) then
|
|
return true;
|
|
else
|
|
return false;
|
|
end if;
|
|
end function Isnan;
|
|
|
|
-- Function to return constants.
|
|
function zerofp (
|
|
constant exponent_width : NATURAL := float_exponent_width; -- exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
constant result : UNRESOLVED_float (exponent_width downto -fraction_width) :=
|
|
(others => '0'); -- zero
|
|
begin
|
|
return result;
|
|
end function zerofp;
|
|
|
|
function nanfp (
|
|
constant exponent_width : NATURAL := float_exponent_width; -- exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width) :=
|
|
(others => '0'); -- zero
|
|
begin
|
|
result (exponent_width-1 downto 0) := (others => '1');
|
|
-- Exponent all "1"
|
|
result (-1) := '1'; -- MSB of Fraction "1"
|
|
-- Note: From W. Khan "IEEE Standard 754 for Binary Floating Point"
|
|
-- The difference between a signaling NAN and a quiet NAN is that
|
|
-- the MSB of the Fraction is a "1" in a Signaling NAN, and is a
|
|
-- "0" in a quiet NAN.
|
|
return result;
|
|
end function nanfp;
|
|
|
|
function qnanfp (
|
|
constant exponent_width : NATURAL := float_exponent_width; -- exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width) :=
|
|
(others => '0'); -- zero
|
|
begin
|
|
result (exponent_width-1 downto 0) := (others => '1');
|
|
-- Exponent all "1"
|
|
result (-fraction_width) := '1'; -- LSB of Fraction "1"
|
|
-- (Could have been any bit)
|
|
return result;
|
|
end function qnanfp;
|
|
|
|
function pos_inffp (
|
|
constant exponent_width : NATURAL := float_exponent_width; -- exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width) :=
|
|
(others => '0'); -- zero
|
|
begin
|
|
result (exponent_width-1 downto 0) := (others => '1'); -- Exponent all "1"
|
|
return result;
|
|
end function pos_inffp;
|
|
|
|
function neg_inffp (
|
|
constant exponent_width : NATURAL := float_exponent_width; -- exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width) :=
|
|
(others => '0'); -- zero
|
|
begin
|
|
result (exponent_width downto 0) := (others => '1'); -- top bits all "1"
|
|
return result;
|
|
end function neg_inffp;
|
|
|
|
function neg_zerofp (
|
|
constant exponent_width : NATURAL := float_exponent_width; -- exponent
|
|
constant fraction_width : NATURAL := float_fraction_width) -- fraction
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width) :=
|
|
(others => '0'); -- zero
|
|
begin
|
|
result (exponent_width) := '1';
|
|
return result;
|
|
end function neg_zerofp;
|
|
|
|
-- size_res versions
|
|
function zerofp (
|
|
size_res : UNRESOLVED_float) -- variable is only use for sizing
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return zerofp (
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function zerofp;
|
|
|
|
function nanfp (
|
|
size_res : UNRESOLVED_float) -- variable is only use for sizing
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return nanfp (
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function nanfp;
|
|
|
|
function qnanfp (
|
|
size_res : UNRESOLVED_float) -- variable is only use for sizing
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return qnanfp (
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function qnanfp;
|
|
|
|
function pos_inffp (
|
|
size_res : UNRESOLVED_float) -- variable is only use for sizing
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return pos_inffp (
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function pos_inffp;
|
|
|
|
function neg_inffp (
|
|
size_res : UNRESOLVED_float) -- variable is only use for sizing
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return neg_inffp (
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function neg_inffp;
|
|
|
|
function neg_zerofp (
|
|
size_res : UNRESOLVED_float) -- variable is only use for sizing
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return neg_zerofp (
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function neg_zerofp;
|
|
|
|
-- Textio functions
|
|
-- purpose: writes float into a line (NOTE changed basetype)
|
|
type MVL9plus is ('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-', error);
|
|
type char_indexed_by_MVL9 is array (STD_ULOGIC) of CHARACTER;
|
|
type MVL9_indexed_by_char is array (CHARACTER) of STD_ULOGIC;
|
|
type MVL9plus_indexed_by_char is array (CHARACTER) of MVL9plus;
|
|
|
|
constant NBSP : CHARACTER := CHARACTER'val(160); -- space character
|
|
constant MVL9_to_char : char_indexed_by_MVL9 := "UX01ZWLH-";
|
|
constant char_to_MVL9 : MVL9_indexed_by_char :=
|
|
('U' => 'U', 'X' => 'X', '0' => '0', '1' => '1', 'Z' => 'Z',
|
|
'W' => 'W', 'L' => 'L', 'H' => 'H', '-' => '-', others => 'U');
|
|
constant char_to_MVL9plus : MVL9plus_indexed_by_char :=
|
|
('U' => 'U', 'X' => 'X', '0' => '0', '1' => '1', 'Z' => 'Z',
|
|
'W' => 'W', 'L' => 'L', 'H' => 'H', '-' => '-', others => error);
|
|
|
|
-- purpose: Skips white space
|
|
procedure skip_whitespace (
|
|
L : inout LINE) is
|
|
variable c : CHARACTER;
|
|
variable left : positive;
|
|
begin
|
|
while L /= null and L.all'length /= 0 loop
|
|
left := L.all'left;
|
|
c := L.all(left);
|
|
if (c = ' ' or c = NBSP or c = HT) then
|
|
read (L, c);
|
|
else
|
|
exit;
|
|
end if;
|
|
end loop;
|
|
end procedure skip_whitespace;
|
|
|
|
-- purpose: Checks the punctuation in a line
|
|
procedure check_punctuation (
|
|
arg : in STRING;
|
|
colon : out BOOLEAN; -- There was a colon in the line
|
|
dot : out BOOLEAN; -- There was a dot in the line
|
|
good : out BOOLEAN; -- True if enough characters found
|
|
chars : in INTEGER) is
|
|
-- Examples. Legal inputs are "0000000", "0000.000", "0:000:000"
|
|
alias xarg : STRING (1 to arg'length) is arg; -- make it downto range
|
|
variable icolon, idot : BOOLEAN; -- internal
|
|
variable j : INTEGER := 0; -- charters read
|
|
begin
|
|
good := false;
|
|
icolon := false;
|
|
idot := false;
|
|
for i in 1 to arg'length loop
|
|
if xarg(i) = ' ' or xarg(i) = NBSP or xarg(i) = HT or j = chars then
|
|
exit;
|
|
elsif xarg(i) = ':' then
|
|
icolon := true;
|
|
elsif xarg(i) = '.' then
|
|
idot := true;
|
|
elsif xarg (i) /= '_' then
|
|
j := j + 1;
|
|
end if;
|
|
end loop;
|
|
if j = chars then
|
|
good := true; -- There are enough charactes to read
|
|
end if;
|
|
colon := icolon;
|
|
if idot and icolon then
|
|
dot := false;
|
|
else
|
|
dot := idot;
|
|
end if;
|
|
end procedure check_punctuation;
|
|
|
|
-- purpose: Searches a line for a ":" and replaces it with a ".".
|
|
procedure fix_colon (
|
|
arg : inout STRING;
|
|
chars : in integer) is
|
|
alias xarg : STRING (1 to arg'length) is arg; -- make it downto range
|
|
variable j : INTEGER := 0; -- charters read
|
|
begin
|
|
for i in 1 to arg'length loop
|
|
if xarg(i) = ' ' or xarg(i) = NBSP or xarg(i) = HT or j > chars then
|
|
exit;
|
|
elsif xarg(i) = ':' then
|
|
xarg (i) := '.';
|
|
elsif xarg (i) /= '_' then
|
|
j := j + 1;
|
|
end if;
|
|
end loop;
|
|
end procedure fix_colon;
|
|
|
|
procedure WRITE (
|
|
L : inout LINE; -- input line
|
|
VALUE : in UNRESOLVED_float; -- floating point input
|
|
JUSTIFIED : in SIDE := right;
|
|
FIELD : in WIDTH := 0) is
|
|
variable s : STRING(1 to VALUE'high - VALUE'low +3);
|
|
variable sindx : INTEGER;
|
|
begin -- function write
|
|
s(1) := MVL9_to_char(STD_ULOGIC(VALUE(VALUE'high)));
|
|
s(2) := ':';
|
|
sindx := 3;
|
|
for i in VALUE'high-1 downto 0 loop
|
|
s(sindx) := MVL9_to_char(STD_ULOGIC(VALUE(i)));
|
|
sindx := sindx + 1;
|
|
end loop;
|
|
s(sindx) := ':';
|
|
sindx := sindx + 1;
|
|
for i in -1 downto VALUE'low loop
|
|
s(sindx) := MVL9_to_char(STD_ULOGIC(VALUE(i)));
|
|
sindx := sindx + 1;
|
|
end loop;
|
|
WRITE (L, s, JUSTIFIED, FIELD);
|
|
end procedure WRITE;
|
|
|
|
procedure READ (L : inout LINE; VALUE : out UNRESOLVED_float) is
|
|
-- Possible data: 0:0000:0000000
|
|
-- 000000000000
|
|
variable c : CHARACTER;
|
|
variable mv : UNRESOLVED_float (VALUE'range);
|
|
variable readOk : BOOLEAN;
|
|
variable lastu : BOOLEAN := false; -- last character was an "_"
|
|
variable i : INTEGER; -- index variable
|
|
begin -- READ
|
|
VALUE := (VALUE'range => 'U'); -- initialize to a "U"
|
|
skip_whitespace (L);
|
|
READ (L, c, readOk);
|
|
if VALUE'length > 0 then
|
|
i := VALUE'high;
|
|
readloop : loop
|
|
if readOk = false then -- Bail out if there was a bad read
|
|
report float_generic_pkg'instance_name
|
|
& "READ(float): "
|
|
& "Error end of file encountered."
|
|
severity error;
|
|
return;
|
|
elsif c = ' ' or c = CR or c = HT then -- reading done.
|
|
if (i /= VALUE'low) then
|
|
report float_generic_pkg'instance_name
|
|
& "READ(float): "
|
|
& "Warning: Value truncated."
|
|
severity warning;
|
|
return;
|
|
end if;
|
|
elsif c = '_' then
|
|
if i = VALUE'high then -- Begins with an "_"
|
|
report float_generic_pkg'instance_name
|
|
& "READ(float): "
|
|
& "String begins with an ""_""" severity error;
|
|
return;
|
|
elsif lastu then -- "__" detected
|
|
report float_generic_pkg'instance_name
|
|
& "READ(float): "
|
|
& "Two underscores detected in input string ""__"""
|
|
severity error;
|
|
return;
|
|
else
|
|
lastu := true;
|
|
end if;
|
|
elsif c = ':' or c = '.' then -- separator, ignore
|
|
if not (i = -1 or i = VALUE'high-1) then
|
|
report float_generic_pkg'instance_name
|
|
& "READ(float): "
|
|
& "Warning: Separator point does not match number format: '"
|
|
& c & "' encountered at location " & INTEGER'image(i) & "."
|
|
severity warning;
|
|
end if;
|
|
lastu := false;
|
|
elsif (char_to_MVL9plus(c) = error) then
|
|
report float_generic_pkg'instance_name
|
|
& "READ(float): "
|
|
& "Error: Character '" & c & "' read, expected STD_ULOGIC literal."
|
|
severity error;
|
|
return;
|
|
else
|
|
mv (i) := char_to_MVL9(c);
|
|
i := i - 1;
|
|
if i < VALUE'low then
|
|
VALUE := mv;
|
|
return;
|
|
end if;
|
|
lastu := false;
|
|
end if;
|
|
READ (L, c, readOk);
|
|
end loop readloop;
|
|
end if;
|
|
end procedure READ;
|
|
|
|
procedure READ (L : inout LINE; VALUE : out UNRESOLVED_float; GOOD : out BOOLEAN) is
|
|
-- Possible data: 0:0000:0000000
|
|
-- 000000000000
|
|
variable c : CHARACTER;
|
|
variable mv : UNRESOLVED_float (VALUE'range);
|
|
variable lastu : BOOLEAN := false; -- last character was an "_"
|
|
variable i : INTEGER; -- index variable
|
|
variable readOk : BOOLEAN;
|
|
begin -- READ
|
|
VALUE := (VALUE'range => 'U'); -- initialize to a "U"
|
|
skip_whitespace (L);
|
|
READ (L, c, readOk);
|
|
if VALUE'length > 0 then
|
|
i := VALUE'high;
|
|
GOOD := false;
|
|
readloop : loop
|
|
if readOk = false then -- Bail out if there was a bad read
|
|
return;
|
|
elsif c = ' ' or c = CR or c = HT then -- reading done
|
|
return;
|
|
elsif c = '_' then
|
|
if i = 0 then -- Begins with an "_"
|
|
return;
|
|
elsif lastu then -- "__" detected
|
|
return;
|
|
else
|
|
lastu := true;
|
|
end if;
|
|
elsif c = ':' or c = '.' then -- separator, ignore
|
|
-- good := (i = -1 or i = value'high-1);
|
|
lastu := false;
|
|
elsif (char_to_MVL9plus(c) = error) then
|
|
return;
|
|
else
|
|
mv (i) := char_to_MVL9(c);
|
|
i := i - 1;
|
|
if i < VALUE'low then
|
|
GOOD := true;
|
|
VALUE := mv;
|
|
return;
|
|
end if;
|
|
lastu := false;
|
|
end if;
|
|
READ (L, c, readOk);
|
|
end loop readloop;
|
|
else
|
|
GOOD := true; -- read into a null array
|
|
end if;
|
|
end procedure READ;
|
|
|
|
procedure OWRITE (
|
|
L : inout LINE; -- access type (pointer)
|
|
VALUE : in UNRESOLVED_float; -- value to write
|
|
JUSTIFIED : in SIDE := right; -- which side to justify text
|
|
FIELD : in WIDTH := 0) is -- width of field
|
|
begin
|
|
WRITE (L => L,
|
|
VALUE => to_ostring(VALUE),
|
|
JUSTIFIED => JUSTIFIED,
|
|
FIELD => FIELD);
|
|
end procedure OWRITE;
|
|
|
|
procedure OREAD (L : inout LINE; VALUE : out UNRESOLVED_float) is
|
|
constant ne : INTEGER := ((VALUE'length+2)/3) * 3; -- pad
|
|
variable slv : STD_LOGIC_VECTOR (ne-1 downto 0); -- slv
|
|
variable slvu : ufixed (VALUE'range); -- Unsigned fixed point
|
|
variable c : CHARACTER;
|
|
variable ok : BOOLEAN;
|
|
variable nybble : STD_LOGIC_VECTOR (2 downto 0); -- 3 bits
|
|
variable colon, dot : BOOLEAN;
|
|
begin
|
|
VALUE := (VALUE'range => 'U'); -- initialize to a "U"
|
|
skip_whitespace (L);
|
|
if VALUE'length > 0 then
|
|
check_punctuation (arg => L.all,
|
|
colon => colon,
|
|
dot => dot,
|
|
good => ok,
|
|
chars => ne/3);
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "short string encounted: " & L.all
|
|
& " needs to have " & integer'image (ne/3)
|
|
& " valid octal characters."
|
|
severity error;
|
|
return;
|
|
elsif dot then
|
|
OREAD (L, slvu, ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "error encounted reading STRING " & L.all
|
|
severity error;
|
|
return;
|
|
else
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
elsif colon then
|
|
OREAD (L, nybble, ok); -- read the sign bit
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "End of string encountered"
|
|
severity error;
|
|
return;
|
|
elsif nybble (2 downto 1) /= "00" then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "Illegal sign bit STRING encounted "
|
|
severity error;
|
|
return;
|
|
end if;
|
|
read (L, c, ok); -- read the colon
|
|
fix_colon (L.all, ne/3); -- replaces the colon with a ".".
|
|
OREAD (L, slvu (slvu'high-1 downto slvu'low), ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "error encounted reading STRING " & L.all
|
|
severity error;
|
|
return;
|
|
else
|
|
slvu (slvu'high) := nybble (0);
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
else
|
|
OREAD (L, slv, ok);
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "Error encounted during read"
|
|
severity error;
|
|
return;
|
|
end if;
|
|
if (or (slv(ne-1 downto VALUE'high-VALUE'low+1)) = '1') then
|
|
report float_generic_pkg'instance_name & "OREAD: "
|
|
& "Vector truncated."
|
|
severity error;
|
|
return;
|
|
end if;
|
|
VALUE := to_float (slv(VALUE'high-VALUE'low downto 0),
|
|
VALUE'high, -VALUE'low);
|
|
end if;
|
|
end if;
|
|
end procedure OREAD;
|
|
|
|
procedure OREAD(L : inout LINE; VALUE : out UNRESOLVED_float; GOOD : out BOOLEAN) is
|
|
constant ne : INTEGER := ((VALUE'length+2)/3) * 3; -- pad
|
|
variable slv : STD_LOGIC_VECTOR (ne-1 downto 0); -- slv
|
|
variable slvu : ufixed (VALUE'range); -- Unsigned fixed point
|
|
variable c : CHARACTER;
|
|
variable ok : BOOLEAN;
|
|
variable nybble : STD_LOGIC_VECTOR (2 downto 0); -- 3 bits
|
|
variable colon, dot : BOOLEAN;
|
|
begin
|
|
VALUE := (VALUE'range => 'U'); -- initialize to a "U"
|
|
GOOD := false;
|
|
skip_whitespace (L);
|
|
if VALUE'length > 0 then
|
|
check_punctuation (arg => L.all,
|
|
colon => colon,
|
|
dot => dot,
|
|
good => ok,
|
|
chars => ne/3);
|
|
if not ok then
|
|
return;
|
|
elsif dot then
|
|
OREAD (L, slvu, ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
return;
|
|
else
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
elsif colon then
|
|
OREAD (L, nybble, ok); -- read the sign bit
|
|
if not ok then
|
|
return;
|
|
elsif nybble (2 downto 1) /= "00" then
|
|
return;
|
|
end if;
|
|
read (L, c, ok); -- read the colon
|
|
fix_colon (L.all, ne/3); -- replaces the colon with a ".".
|
|
OREAD (L, slvu (slvu'high-1 downto slvu'low), ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
return;
|
|
else
|
|
slvu (slvu'high) := nybble (0);
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
else
|
|
OREAD (L, slv, ok);
|
|
if not ok then
|
|
return;
|
|
end if;
|
|
if (or (slv(ne-1 downto VALUE'high-VALUE'low+1)) = '1') then
|
|
return;
|
|
end if;
|
|
VALUE := to_float (slv(VALUE'high-VALUE'low downto 0),
|
|
VALUE'high, -VALUE'low);
|
|
end if;
|
|
GOOD := true;
|
|
end if;
|
|
end procedure OREAD;
|
|
|
|
procedure HWRITE (
|
|
L : inout LINE; -- access type (pointer)
|
|
VALUE : in UNRESOLVED_float; -- value to write
|
|
JUSTIFIED : in SIDE := right; -- which side to justify text
|
|
FIELD : in WIDTH := 0) is -- width of field
|
|
begin
|
|
WRITE (L => L,
|
|
VALUE => to_hstring(VALUE),
|
|
JUSTIFIED => JUSTIFIED,
|
|
FIELD => FIELD);
|
|
end procedure HWRITE;
|
|
|
|
procedure HREAD (L : inout LINE; VALUE : out UNRESOLVED_float) is
|
|
constant ne : INTEGER := ((VALUE'length+3)/4) * 4; -- pad
|
|
variable slv : STD_LOGIC_VECTOR (ne-1 downto 0); -- slv
|
|
variable slvu : ufixed (VALUE'range); -- Unsigned fixed point
|
|
variable c : CHARACTER;
|
|
variable ok : BOOLEAN;
|
|
variable nybble : STD_LOGIC_VECTOR (3 downto 0); -- 4 bits
|
|
variable colon, dot : BOOLEAN;
|
|
begin
|
|
VALUE := (VALUE'range => 'U'); -- initialize to a "U"
|
|
skip_whitespace (L);
|
|
if VALUE'length > 0 then
|
|
check_punctuation (arg => L.all,
|
|
colon => colon,
|
|
dot => dot,
|
|
good => ok,
|
|
chars => ne/4);
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "short string encounted: " & L.all
|
|
& " needs to have " & integer'image (ne/4)
|
|
& " valid hex characters."
|
|
severity error;
|
|
return;
|
|
elsif dot then
|
|
HREAD (L, slvu, ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "error encounted reading STRING " & L.all
|
|
severity error;
|
|
return;
|
|
else
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
elsif colon then
|
|
HREAD (L, nybble, ok); -- read the sign bit
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "End of string encountered"
|
|
severity error;
|
|
return;
|
|
elsif nybble (3 downto 1) /= "000" then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "Illegal sign bit STRING encounted "
|
|
severity error;
|
|
return;
|
|
end if;
|
|
read (L, c, ok); -- read the colon
|
|
fix_colon (L.all, ne/4); -- replaces the colon with a ".".
|
|
HREAD (L, slvu (slvu'high-1 downto slvu'low), ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "error encounted reading STRING " & L.all
|
|
severity error;
|
|
return;
|
|
else
|
|
slvu (slvu'high) := nybble (0);
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
else
|
|
HREAD (L, slv, ok);
|
|
if not ok then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "Error encounted during read"
|
|
severity error;
|
|
return;
|
|
end if;
|
|
if (or (slv(ne-1 downto VALUE'high-VALUE'low+1)) = '1') then
|
|
report float_generic_pkg'instance_name & "HREAD: "
|
|
& "Vector truncated."
|
|
severity error;
|
|
return;
|
|
end if;
|
|
VALUE := to_float (slv(VALUE'high-VALUE'low downto 0),
|
|
VALUE'high, -VALUE'low);
|
|
end if;
|
|
end if;
|
|
end procedure HREAD;
|
|
|
|
procedure HREAD (L : inout LINE; VALUE : out UNRESOLVED_float; GOOD : out BOOLEAN) is
|
|
constant ne : INTEGER := ((VALUE'length+3)/4) * 4; -- pad
|
|
variable slv : STD_LOGIC_VECTOR (ne-1 downto 0); -- slv
|
|
variable slvu : ufixed (VALUE'range); -- Unsigned fixed point
|
|
variable c : CHARACTER;
|
|
variable ok : BOOLEAN;
|
|
variable nybble : STD_LOGIC_VECTOR (3 downto 0); -- 4 bits
|
|
variable colon, dot : BOOLEAN;
|
|
begin
|
|
VALUE := (VALUE'range => 'U'); -- initialize to a "U"
|
|
GOOD := false;
|
|
skip_whitespace (L);
|
|
if VALUE'length > 0 then
|
|
check_punctuation (arg => L.all,
|
|
colon => colon,
|
|
dot => dot,
|
|
good => ok,
|
|
chars => ne/4);
|
|
if not ok then
|
|
return;
|
|
elsif dot then
|
|
HREAD (L, slvu, ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
return;
|
|
else
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
elsif colon then
|
|
HREAD (L, nybble, ok); -- read the sign bit
|
|
if not ok then
|
|
return;
|
|
elsif nybble (3 downto 1) /= "000" then
|
|
return;
|
|
end if;
|
|
read (L, c, ok); -- read the colon
|
|
fix_colon (L.all, ne/4); -- replaces the colon with a ".".
|
|
HREAD (L, slvu (slvu'high-1 downto slvu'low), ok); -- read it like a UFIXED number
|
|
if not ok then
|
|
return;
|
|
else
|
|
slvu (slvu'high) := nybble (0);
|
|
VALUE := UNRESOLVED_float (slvu);
|
|
end if;
|
|
else
|
|
HREAD (L, slv, ok);
|
|
if not ok then
|
|
return;
|
|
end if;
|
|
if (or (slv(ne-1 downto VALUE'high-VALUE'low+1)) = '1') then
|
|
return;
|
|
end if;
|
|
VALUE := to_float (slv(VALUE'high-VALUE'low downto 0),
|
|
VALUE'high, -VALUE'low);
|
|
end if;
|
|
GOOD := true;
|
|
end if;
|
|
end procedure HREAD;
|
|
|
|
function to_string (value : UNRESOLVED_float) return STRING is
|
|
variable s : STRING(1 to value'high - value'low +3);
|
|
variable sindx : INTEGER;
|
|
begin -- function write
|
|
s(1) := MVL9_to_char(STD_ULOGIC(value(value'high)));
|
|
s(2) := ':';
|
|
sindx := 3;
|
|
for i in value'high-1 downto 0 loop
|
|
s(sindx) := MVL9_to_char(STD_ULOGIC(value(i)));
|
|
sindx := sindx + 1;
|
|
end loop;
|
|
s(sindx) := ':';
|
|
sindx := sindx + 1;
|
|
for i in -1 downto value'low loop
|
|
s(sindx) := MVL9_to_char(STD_ULOGIC(value(i)));
|
|
sindx := sindx + 1;
|
|
end loop;
|
|
return s;
|
|
end function to_string;
|
|
|
|
function to_hstring (value : UNRESOLVED_float) return STRING is
|
|
variable slv : STD_LOGIC_VECTOR (value'length-1 downto 0);
|
|
begin
|
|
floop : for i in slv'range loop
|
|
slv(i) := to_X01Z (value(i + value'low));
|
|
end loop floop;
|
|
return to_hstring (slv);
|
|
end function to_hstring;
|
|
|
|
function to_ostring (value : UNRESOLVED_float) return STRING is
|
|
variable slv : STD_LOGIC_VECTOR (value'length-1 downto 0);
|
|
begin
|
|
floop : for i in slv'range loop
|
|
slv(i) := to_X01Z (value(i + value'low));
|
|
end loop floop;
|
|
return to_ostring (slv);
|
|
end function to_ostring;
|
|
|
|
function from_string (
|
|
bstring : STRING; -- binary string
|
|
constant exponent_width : NATURAL := float_exponent_width;
|
|
constant fraction_width : NATURAL := float_fraction_width)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable L : LINE;
|
|
variable good : BOOLEAN;
|
|
begin
|
|
L := new STRING'(bstring);
|
|
READ (L, result, good);
|
|
deallocate (L);
|
|
assert (good)
|
|
report float_generic_pkg'instance_name
|
|
& "from_string: Bad string " & bstring
|
|
severity error;
|
|
return result;
|
|
end function from_string;
|
|
|
|
function from_ostring (
|
|
ostring : STRING; -- Octal string
|
|
constant exponent_width : NATURAL := float_exponent_width;
|
|
constant fraction_width : NATURAL := float_fraction_width)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable L : LINE;
|
|
variable good : BOOLEAN;
|
|
begin
|
|
L := new STRING'(ostring);
|
|
OREAD (L, result, good);
|
|
deallocate (L);
|
|
assert (good)
|
|
report float_generic_pkg'instance_name
|
|
& "from_ostring: Bad string " & ostring
|
|
severity error;
|
|
return result;
|
|
end function from_ostring;
|
|
|
|
function from_hstring (
|
|
hstring : STRING; -- hex string
|
|
constant exponent_width : NATURAL := float_exponent_width;
|
|
constant fraction_width : NATURAL := float_fraction_width)
|
|
return UNRESOLVED_float
|
|
is
|
|
variable result : UNRESOLVED_float (exponent_width downto -fraction_width);
|
|
variable L : LINE;
|
|
variable good : BOOLEAN;
|
|
begin
|
|
L := new STRING'(hstring);
|
|
HREAD (L, result, good);
|
|
deallocate (L);
|
|
assert (good)
|
|
report float_generic_pkg'instance_name
|
|
& "from_hstring: Bad string " & hstring
|
|
severity error;
|
|
return result;
|
|
end function from_hstring;
|
|
|
|
function from_string (
|
|
bstring : STRING; -- binary string
|
|
size_res : UNRESOLVED_float) -- used for sizing only
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return from_string (bstring => bstring,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function from_string;
|
|
|
|
function from_ostring (
|
|
ostring : STRING; -- Octal string
|
|
size_res : UNRESOLVED_float) -- used for sizing only
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return from_ostring (ostring => ostring,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function from_ostring;
|
|
|
|
function from_hstring (
|
|
hstring : STRING; -- hex string
|
|
size_res : UNRESOLVED_float) -- used for sizing only
|
|
return UNRESOLVED_float is
|
|
begin
|
|
return from_hstring (hstring => hstring,
|
|
exponent_width => size_res'high,
|
|
fraction_width => -size_res'low);
|
|
end function from_hstring;
|
|
|
|
end package body float_generic_pkg;
|