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------------------------------------------------ --! @file fadd32.vhd --! @brief RayTrac Floating Point Adder --! @author Julián Andrés Guarín Reyes -------------------------------------------------- -- RAYTRAC (FP BRANCH) -- Author Julian Andres Guarin -- fadd32.vhd -- This file is part of raytrac. -- -- raytrac is free software: you can redistribute it and/or modify -- it under the terms of the GNU General Public License as published by -- the Free Software Foundation, either version 3 of the License, or -- (at your option) any later version. -- -- raytrac is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License -- along with raytrac. If not, see <http://www.gnu.org/licenses/> library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_unsigned.all; library lpm; use lpm.all; --! Esta entidad recibe dos números en formato punto flotante IEEE 754, de precision simple y devuelve las mantissas signadas y corridas, y el exponente correspondiente al resultado antes de normalizarlo al formato float. --!\nLas 2 mantissas y el exponente entran despues a la entidad add2 que suma las mantissas y entrega el resultado en formato IEEE 754. entity fadd32 is port ( clk,dpc,ena : in std_logic; a32,b32 : in std_logic_vector (31 downto 0); c32 : out std_logic_vector(31 downto 0) ); end fadd32; architecture fadd32_arch of fadd32 is component lpm_mult generic ( lpm_hint : string; lpm_representation : string; lpm_type : string; lpm_widtha : natural; lpm_widthb : natural; lpm_widthp : natural ); port ( dataa : in std_logic_vector ( lpm_widtha-1 downto 0 ); datab : in std_logic_vector ( lpm_widthb-1 downto 0 ); result : out std_logic_vector( lpm_widthp-1 downto 0 ) ); end component; signal s1zero,s5tokena,s5tokenb,s5tokenc,s7sign : std_logic; signal s5token : std_logic_vector(2 downto 0); signal s1delta : std_logic_vector(5 downto 0); signal s0delta,s1exp,s2exp,s3exp,s4exp,s5exp,s6exp,s5factor,s6factor,s7exp,s7factor : std_logic_vector(7 downto 0); signal s1shifter,s5factorhot9,s6factorhot9 : std_logic_vector(8 downto 0); signal s1pl,s6pl : std_logic_vector(17 downto 0); signal s6postshift,s7postshift : std_logic_vector(22 downto 0); signal s1umantshift,s1umantfixed,s1postshift,s1xorslab,s2xorslab : std_logic_vector(23 downto 0); signal s5factorhot24 : std_logic_vector(23 downto 0); signal s2umantshift,s2mantfixed,s3mantfixed,s3mantshift,s4xorslab : std_logic_vector(24 downto 0); signal s4sresult,s5result,s6result : std_logic_vector(25 downto 0); -- Signed mantissa result signal s1ph,s6ph : std_logic_vector(26 downto 0); signal s0a,s0b : std_logic_vector(31 downto 0); -- Float 32 bit begin process (clk,ena) begin if clk'event and clk='1' and ena='1' then --!Registro de entrada s0a <= a32; s0b(31) <= dpc xor b32(31); --! Importante: Integrar el signo en el operando B s0b(30 downto 0) <= b32(30 downto 0); --!Etapa 0,Escoger el mayor exponente que sera el resultado desnormalizado, calcula cuanto debe ser el corrimiento de la mantissa con menor exponente y reorganiza los operandos, si el mayor es b, intercambia las posición si el mayor es a las posiciones la mantiene. Zero check. --!signo,exponente,mantissa if (s0b(30 downto 23)&s0a(30 downto 23))=x"0000" then s1zero <= '0'; else s1zero <= '1'; end if; s1delta <= s0delta(7) & (s0delta(7) xor s0delta(4))&(s0delta(7) xor s0delta(3)) & s0delta(2 downto 0); case s0delta(7) is when '1' => s1exp <= s0b(30 downto 23); s1umantshift <= s0a(31)&s0a(22 downto 0); s1umantfixed <= s0b(31)&s0b(22 downto 0); when others => s1exp <= s0a(30 downto 23); s1umantshift <= s0b(31)&s0b(22 downto 0); s1umantfixed <= s0a(31)&s0a(22 downto 0); end case; --! Etapa 1: Denormalización de la mantissas. case s1delta(4 downto 3) is when "00" => s2umantshift <= s1umantshift(23)&s1postshift(23 downto 0); when "01" => s2umantshift <= s1umantshift(23)&x"00"&s1postshift(23 downto 8); when "10" => s2umantshift <= s1umantshift(23)&x"0000"&s1postshift(23 downto 16); when others => s2umantshift <= (others => '0'); end case; s2mantfixed <= s1umantfixed(23) & ( ( ('1'&s1umantfixed(22 downto 0)) xor s1xorslab) + ( x"00000"&"000"&s1umantfixed(23) ) ); s2exp <= s1exp; --! Etapa2: Signar la mantissa denormalizada. s3mantfixed <= s2mantfixed; s3mantshift <= s2umantshift(24)& ( ( s2umantshift(23 downto 0) xor s2xorslab) + ( x"00000"&"000"&s2umantshift(24) ) ); s3exp <= s2exp; --! Etapa 3: Etapa 3 Realizar la suma, entre la mantissa corrida y la fija. s4sresult <= (s3mantshift(24)&s3mantshift)+(s3mantfixed(24)&s3mantfixed); s4exp <= s3exp; --! Etapa 4: Quitar el signo a la mantissa resultante. s5result <= s4sresult(25)&((s4sresult(24 downto 0) xor s4xorslab) +(x"000000"&s4sresult(25))); s5exp <= s4exp; --! Etapa 5: Codificar el corrimiento para la normalizacion de la mantissa resultante. s6result <= s5result; s6exp <= s5exp; s6factor <= s5factor; s6factorhot9 <= s5factorhot9; --! Etapa 6: Ejecutar el corrimiento de la mantissa. s7sign <= s6result(25); s7exp <= s6exp; s7factor <= s6factor; s7postshift <= s6postshift; end if; end process; --! Etapa 7: Entregar el resultado. c32(31) <= s7sign; process(s7exp,s7postshift,s7factor) begin c32(30 downto 23) <= s7exp+s7factor; case s7factor(4 downto 3) is when "01" => c32(22 downto 0) <= s7postshift(14 downto 00)&x"00"; when "10" => c32(22 downto 0) <= s7postshift(06 downto 00)&x"0000"; when others => c32(22 downto 0) <= s7postshift; end case; end process; --! Combinatorial gremlin, Etapa 0 el corrimiento de la mantissa con menor exponente y reorganiza los operandos,\n --! si el mayor es b, intercambia las posición si el mayor es a las posiciones la mantiene. s0delta <= s0a(30 downto 23)-s0b(30 downto 23); --! Combinatorial Gremlin, Etapa 1 Codificar el factor de corrimiento de denormalizacion y denormalizar la mantissa no fija. Signar la mantissa que se queda fija. decodeshiftfactor: process (s1delta(2 downto 0)) begin case s1delta(2 downto 0) is when "111" => s1shifter(8 downto 0) <= '0'&s1delta(5)&"00000"¬(s1delta(5))&'0'; when "110" => s1shifter(8 downto 0) <= "00"&s1delta(5)&"000"¬(s1delta(5))&"00"; when "101" => s1shifter(8 downto 0) <= "000"&s1delta(5)&'0'¬(s1delta(5))&"000"; when "100" => s1shifter(8 downto 0) <= '0'&x"10"; when "011" => s1shifter(8 downto 0) <= "000"¬(s1delta(5))&'0'&s1delta(5)&"000"; when "010" => s1shifter(8 downto 0) <= "00"¬(s1delta(5))&"000"&s1delta(5)&"00"; when "001" => s1shifter(8 downto 0) <= '0'¬(s1delta(5))&"00000"&s1delta(5)&'0'; when others => s1shifter(8 downto 0) <= not(s1delta(5))&"0000000"&s1delta(5); end case; end process; denormhighshiftermult:lpm_mult generic map ("DEDICATED_MULTIPLIER_CIRCUITRY=YES,MAXIMIZE_SPEED=9","UNSIGNED","LPM_MULT",9,18,27) port map (s1shifter,s1zero&s1umantshift(22 downto 06),s1ph); denormlowshiftermult:lpm_mult generic map ("DEDICATED_MULTIPLIER_CIRCUITRY=YES,MAXIMIZE_SPEED=9","UNSIGNED","LPM_MULT",9,9,18) port map (s1shifter,s1umantshift(5 downto 0)&"000",s1pl); s1postshift(23 downto 7) <= s1ph(25 downto 9); s1postshift(06 downto 0) <= s1ph(08 downto 2) or s1pl(17 downto 11); s1xorslab(23 downto 0) <= (others => s1umantfixed(23)); --! Combinatorial Gremlin, Etapa 2: Signar la mantissa denormalizada. s2xorslab <= (others => s2umantshift(24)); --! Combinatorial Gremlin, Etapa 4: Quitar el signo de la mantissa resultante. s4xorslab <= (others => s4sresult(25)); --! Combinatorial Gremlin, Etapa 5: Codificar el factor de normalizacion de la mantissa resultante. normalizerdecodeshift: process (s5result,s5factorhot24,s5token,s5tokena,s5tokenb,s5tokenc,s5factorhot9) begin s5tokena <= not(s5result(24)); s5tokenb <= not(s5result(24)); s5tokenc <= not(s5result(24)); s5factor(7 downto 5) <= (others => s5result(24)); s5factorhot24 <= x"000000"; for i in 23 downto 16 loop if s5result(i)='1' then s5factorhot24(23-i) <= s5tokena; s5tokenb <= '0'; s5tokenc <= '0'; exit; end if; end loop; for i in 15 downto 8 loop if s5result(i)='1' then s5factorhot24(23-i) <= s5tokenb; s5tokenc <= '0'; exit; end if; end loop; for i in 7 downto 0 loop if s5result(i)='1' then s5factorhot24(23-i) <= s5tokenc; exit; end if; end loop; s5token <=s5tokena&s5tokenb&s5tokenc; case (s5token) is when "100" => s5factor(4 downto 3) <= "10"; when "110" => s5factor(4 downto 3) <= "01"; when "111" => s5factor(4 downto 3) <= "00"; when others => s5factor(4 downto 3) <= (others => s5result(24)); end case; s5factorhot9 <= (s5factorhot24(7 downto 0)or s5factorhot24(15 downto 8)or s5factorhot24(23 downto 16)) & s5result(24); case s5factorhot9 is when "100000000" => s5factor(2 downto 0) <= "111"; when "010000000" => s5factor(2 downto 0) <= "110"; when "001000000" => s5factor(2 downto 0) <= "101"; when "000100000" => s5factor(2 downto 0) <= "100"; when "000010000" => s5factor(2 downto 0) <= "011"; when "000001000" => s5factor(2 downto 0) <= "010"; when "000000100" => s5factor(2 downto 0) <= "001"; when "000000010" => s5factor(2 downto 0) <= "000"; when others => s5factor (2 downto 0) <= (others => s5result(24)); end case; end process; --! Etapa 6: Ejecutar el corrimiento para normalizar la mantissa. normhighshiftermult:lpm_mult generic map ("DEDICATED_MULTIPLIER_CIRCUITRY=YES,MAXIMIZE_SPEED=9","UNSIGNED","LPM_MULT",9,18,27) port map (s6factorhot9,s6result(24 downto 7),s6ph); normlowshiftermult:lpm_mult generic map ("DEDICATED_MULTIPLIER_CIRCUITRY=YES,MAXIMIZE_SPEED=9","UNSIGNED","LPM_MULT",9,9,18) port map (s6factorhot9,s6result(06 downto 0)&"00",s6pl); s6postshift(22 downto 15) <= s6ph(16 downto 09); s6postshift(14 downto 06) <= s6ph(08 downto 00) + s6pl(17 downto 09); s6postshift(05 downto 00) <= s6pl(08 downto 03); end fadd32_arch;
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