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aloy.amber |
library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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aloy.amber |
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aloy.amber |
package fp_generic is
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subtype fp_type is std_logic_vector(31 downto 0);
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subtype fp_sign_type is std_logic;
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subtype fp_exp_type is unsigned(7 downto 0);
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subtype fp_mantissa_type is unsigned(23 downto 0);
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subtype fp_long_mantissa_type is unsigned(47 downto 0);
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subtype fp_error_type is std_logic_vector(5 downto 0);
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constant FP_ERR_INVALID:fp_error_type:="000001";
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constant FP_ERR_DIVBYZERO:fp_error_type:="000100";
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constant FP_ERR_OVERFLOW:fp_error_type:="001000";
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constant FP_ERR_UNDERFLOW:fp_error_type:="010000";
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constant FP_ERR_INEXACT:fp_error_type:="100000";
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function fp_sign(fp:fp_type) return fp_sign_type;
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function fp_exp(fp:fp_type) return fp_exp_type;
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function fp_mantissa(fp:fp_type) return fp_mantissa_type;
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function fp_is_normal(fp:fp_type) return boolean;
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function fp_is_zero(fp:fp_type) return boolean;
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function fp_is_subnormal(fp:fp_type) return boolean;
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function fp_is_infinite(fp:fp_type) return boolean;
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function fp_is_nan(fp:fp_type) return boolean;
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function fp_is_signalling(fp:fp_type) return boolean;
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function fp_is_quiet(fp:fp_type) return boolean;
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end package;
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package body fp_generic is
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function fp_sign(fp:fp_type) return fp_sign_type is
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begin
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return fp(31);
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end function fp_sign;
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function fp_exp(fp:fp_type) return fp_exp_type is
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begin
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return(resize((unsigned(fp) srl 23),8));
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end function fp_exp;
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function fp_mantissa(fp:fp_type) return fp_mantissa_type is
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begin
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return(fp_mantissa_type("1"&fp(22 downto 0))); -- Prepend implied '1' bit of IEEE-754 mantissa in order to return a 24 bit entity
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end function fp_mantissa;
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function fp_exp_is_min(exp:fp_exp_type) return boolean is
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begin
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return (exp=0);
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end function fp_exp_is_min;
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function fp_exp_is_max(exp:fp_exp_type) return boolean is
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begin
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return (exp=255);
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end function fp_exp_is_max;
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function fp_is_normal(fp:fp_type) return boolean is
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variable exp:fp_exp_type;
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begin
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exp:=fp_exp(fp);
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return not fp_exp_is_min(exp) and not fp_exp_is_max(exp);
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end function fp_is_normal;
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function fp_is_zero(fp:fp_type) return boolean is
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begin
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return (fp_exp(fp)=0) and (fp_mantissa(fp)=0);
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end function fp_is_zero;
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function fp_is_subnormal(fp:fp_type) return boolean is
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begin
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return (fp_exp(fp)=0) and (fp_mantissa(fp)/=0);
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end function fp_is_subnormal;
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function fp_is_infinite(fp:fp_type) return boolean is
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begin
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return (fp_exp_is_max(fp_exp(fp))) and (fp_mantissa(fp)=0);
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end function fp_is_infinite;
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function fp_is_nan(fp:fp_type) return boolean is
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begin
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return (fp_exp_is_max(fp_exp(fp))) and (fp_mantissa(fp)/=0);
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end function fp_is_nan;
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function fp_is_signalling(fp:fp_type) return boolean is
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begin
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return fp_is_nan(fp) and fp_mantissa(fp)(22)='0';
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end function fp_is_signalling;
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function fp_is_quiet(fp:fp_type) return boolean is
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begin
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return fp_is_nan(fp) and fp_mantissa(fp)(22)='1';
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end function fp_is_quiet;
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end package body fp_generic;
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