Subversion Repositories riscv_vhdl

-----------------------------------------------------------------------------

--! @file

--! @copyright Copyright 2016 GNSS Sensor Ltd. All right reserved.

--! @author    Sergey Khabarov - sergeykhbr@gmail.com

--! @brief     Left/Right shifter arithmetic/logic 32/64 bits.

--! 

--! @details   Vivado synthesizer (2016.2) doesn't support shift

--!            from dynamic value, so implement this mux.

------------------------------------------------------------------------------

library ieee;

use ieee.std_logic_1164.all;

library commonlib;

use commonlib.types_common.all;

--! RIVER CPU specific library.

library riverlib;

--! RIVER CPU configuration constants.

use riverlib.river_cfg.all;

entity Shifter is

  port (

    i_a1 : in std_logic_vector(RISCV_ARCH-1 downto 0);     -- Operand 1

    i_a2 : in std_logic_vector(5 downto 0);                -- Shift bits number

    o_sll : out std_logic_vector(RISCV_ARCH-1 downto 0);   -- Logical shift left 64-bits operand

    o_sllw : out std_logic_vector(RISCV_ARCH-1 downto 0);  -- Logical shift left 32-bits operand

    o_srl : out std_logic_vector(RISCV_ARCH-1 downto 0);   -- Logical shift 64 bits

    o_sra : out std_logic_vector(RISCV_ARCH-1 downto 0);   -- Arith. shift 64 bits

    o_srlw : out std_logic_vector(RISCV_ARCH-1 downto 0);  -- Logical shift 32 bits

    o_sraw : out std_logic_vector(RISCV_ARCH-1 downto 0)   -- Arith. shift 32 bits

  );

end;

architecture arch_Shifter of Shifter is

begin

  comb : process(i_a1, i_a2)

    variable wb_sll : std_logic_vector(63 downto 0);

    variable wb_srl : std_logic_vector(63 downto 0);

    variable wb_sra : std_logic_vector(63 downto 0);

    variable wb_srlw : std_logic_vector(31 downto 0);

    variable wb_sraw : std_logic_vector(63 downto 0);

    variable v64 : std_logic_vector(63 downto 0);

    variable v32 : std_logic_vector(31 downto 0);

    variable msk64 : std_logic_vector(63 downto 0);

    variable msk32 : std_logic_vector(63 downto 0);

    variable shift64 : integer range 0 to 63;

    variable shift32 : integer range 0 to 31;

  begin

    v64 := i_a1;

    v32 := i_a1(31 downto 0);

    msk64 := (others => i_a1(63));

    msk32 := (others => i_a1(31));

    shift64 := conv_integer(i_a2);

    shift32 := conv_integer(i_a2(4 downto 0));

    case shift64 is

    when 0 =>

        wb_sll := v64;

        wb_srl := v64;

        wb_sra := v64;

    when 1 =>

        wb_sll := v64(62 downto 0) & "0";

        wb_srl := "0" & v64(63 downto 1);

        wb_sra := (msk64(63 downto 63) & v64(63 downto 1));

    when 2 =>

        wb_sll := v64(61 downto 0) & "00";

        wb_srl := "00" & v64(63 downto 2);

        wb_sra := (msk64(63 downto 62) & v64(63 downto 2));

    when 3 =>

        wb_sll := v64(60 downto 0) & "000";

        wb_srl := "000" & v64(63 downto 3);

        wb_sra := (msk64(63 downto 61) & v64(63 downto 3));

    when 4 =>

        wb_sll := v64(59 downto 0) & X"0";

        wb_srl := X"0" & v64(63 downto 4);

        wb_sra := (msk64(63 downto 60) & v64(63 downto 4));

    when 5 =>

        wb_sll := v64(58 downto 0) & X"0" & "0";

        wb_srl :=  X"0" & "0" & v64(63 downto 5);

        wb_sra := (msk64(63 downto 59) & v64(63 downto 5));

    when 6 =>

        wb_sll := v64(57 downto 0) & X"0" & "00";

        wb_srl := X"0" & "00" & v64(63 downto 6);

        wb_sra := (msk64(63 downto 58) & v64(63 downto 6));

    when 7 =>

        wb_sll := v64(56 downto 0) & X"0" & "000";

        wb_srl := X"0" & "000" & v64(63 downto 7);

        wb_sra := (msk64(63 downto 57) & v64(63 downto 7));

    when 8 =>

        wb_sll := v64(55 downto 0) & X"00";

        wb_srl := X"00" & v64(63 downto 8);

        wb_sra := (msk64(63 downto 56) & v64(63 downto 8));

    when 9 =>

        wb_sll := v64(54 downto 0) & X"00" & "0";

        wb_srl := X"00" & "0" & v64(63 downto 9);

        wb_sra := (msk64(63 downto 55) & v64(63 downto 9));

    when 10 =>

        wb_sll := v64(53 downto 0) & X"00" & "00";

        wb_srl := X"00" & "00" & v64(63 downto 10);

        wb_sra := (msk64(63 downto 54) & v64(63 downto 10));

    when 11 =>

        wb_sll := v64(52 downto 0) & X"00" & "000";

        wb_srl := X"00" & "000" & v64(63 downto 11);

        wb_sra := (msk64(63 downto 53) & v64(63 downto 11));

    when 12 =>

        wb_sll := v64(51 downto 0) & X"000";

        wb_srl := X"000" & v64(63 downto 12);

        wb_sra := (msk64(63 downto 52) & v64(63 downto 12));

    when 13 =>

        wb_sll := v64(50 downto 0) & X"000" & "0";

        wb_srl := X"000" & "0" & v64(63 downto 13);

        wb_sra := (msk64(63 downto 51) & v64(63 downto 13));

    when 14 =>

        wb_sll := v64(49 downto 0) & X"000" & "00";

        wb_srl := X"000" & "00" & v64(63 downto 14);

        wb_sra := (msk64(63 downto 50) & v64(63 downto 14));

    when 15 =>

        wb_sll := v64(48 downto 0) & X"000" & "000";

        wb_srl := X"000" & "000" & v64(63 downto 15);

        wb_sra := (msk64(63 downto 49) & v64(63 downto 15));

    when 16 =>

        wb_sll := v64(47 downto 0) & X"0000";

        wb_srl := X"0000" & v64(63 downto 16);

        wb_sra := (msk64(63 downto 48) & v64(63 downto 16));

    when 17 =>

        wb_sll := v64(46 downto 0) & X"0000" & "0";

        wb_srl := X"0000" & "0" & v64(63 downto 17);

        wb_sra := (msk64(63 downto 47) & v64(63 downto 17));

    when 18 =>

        wb_sll := v64(45 downto 0) & X"0000" & "00";

        wb_srl := X"0000" & "00" & v64(63 downto 18);

        wb_sra := (msk64(63 downto 46) & v64(63 downto 18));

    when 19 =>

        wb_sll := v64(44 downto 0) & X"0000" & "000";

        wb_srl := X"0000" & "000" & v64(63 downto 19);

        wb_sra := (msk64(63 downto 45) & v64(63 downto 19));

    when 20 =>

        wb_sll := v64(43 downto 0) & X"00000";

        wb_srl := X"00000" & v64(63 downto 20);

        wb_sra := (msk64(63 downto 44) & v64(63 downto 20));

    when 21 =>

        wb_sll := v64(42 downto 0) & X"00000" & "0";

        wb_srl := X"00000" & "0" & v64(63 downto 21);

        wb_sra := (msk64(63 downto 43) & v64(63 downto 21));

    when 22 =>

        wb_sll := v64(41 downto 0) & X"00000" & "00";

        wb_srl := X"00000" & "00" & v64(63 downto 22);

        wb_sra := (msk64(63 downto 42) & v64(63 downto 22));

    when 23 =>

        wb_sll := v64(40 downto 0) & X"00000" & "000";

        wb_srl := X"00000" & "000" & v64(63 downto 23);

        wb_sra := (msk64(63 downto 41) & v64(63 downto 23));

    when 24 =>

        wb_sll := v64(39 downto 0) & X"000000";

        wb_srl := X"000000" & v64(63 downto 24);

        wb_sra := (msk64(63 downto 40) & v64(63 downto 24));

    when 25 =>

        wb_sll := v64(38 downto 0) & X"000000" & "0";

        wb_srl := X"000000" & "0" & v64(63 downto 25);

        wb_sra := (msk64(63 downto 39) & v64(63 downto 25));

    when 26 =>

        wb_sll := v64(37 downto 0) & X"000000" & "00";

        wb_srl := X"000000" & "00" & v64(63 downto 26);

        wb_sra := (msk64(63 downto 38) & v64(63 downto 26));

    when 27 =>

        wb_sll := v64(36 downto 0) & X"000000" & "000";

        wb_srl := X"000000" & "000" & v64(63 downto 27);

        wb_sra := (msk64(63 downto 37) & v64(63 downto 27));

    when 28 =>

        wb_sll := v64(35 downto 0) & X"0000000";

        wb_srl := X"0000000" & v64(63 downto 28);

        wb_sra := (msk64(63 downto 36) & v64(63 downto 28));

    when 29 =>

        wb_sll := v64(34 downto 0) & X"0000000" & "0";

        wb_srl := X"0000000" & "0" & v64(63 downto 29);

        wb_sra := (msk64(63 downto 35) & v64(63 downto 29));

    when 30 =>

        wb_sll := v64(33 downto 0) & X"0000000" & "00";

        wb_srl := X"0000000" & "00" & v64(63 downto 30);

        wb_sra := (msk64(63 downto 34) & v64(63 downto 30));

    when 31 =>

        wb_sll := v64(32 downto 0) & X"0000000" & "000";

        wb_srl := X"0000000" & "000" & v64(63 downto 31);

        wb_sra := (msk64(63 downto 33) & v64(63 downto 31));

    when 32 =>

        wb_sll := v64(31 downto 0) & X"00000000";

        wb_srl := X"00000000" & v64(63 downto 32);

        wb_sra := (msk64(63 downto 32) & v64(63 downto 32));

    when 33 =>

        wb_sll := v64(30 downto 0) & X"00000000" & "0";

        wb_srl := X"00000000" & "0" & v64(63 downto 33);

        wb_sra := (msk64(63 downto 31) & v64(63 downto 33));

    when 34 =>

        wb_sll := v64(29 downto 0) & X"00000000" & "00";

        wb_srl := X"00000000" & "00" & v64(63 downto 34);

        wb_sra := (msk64(63 downto 30) & v64(63 downto 34));

    when 35 =>

        wb_sll := v64(28 downto 0) & X"00000000" & "000";

        wb_srl := X"00000000" & "000" & v64(63 downto 35);

        wb_sra := (msk64(63 downto 29) & v64(63 downto 35));

    when 36 =>

        wb_sll := v64(27 downto 0) & X"000000000";

        wb_srl := X"000000000" & v64(63 downto 36);

        wb_sra := (msk64(63 downto 28) & v64(63 downto 36));

    when 37 =>

        wb_sll := v64(26 downto 0) & X"000000000" & "0";

        wb_srl := X"000000000" & "0" & v64(63 downto 37);

        wb_sra := (msk64(63 downto 27) & v64(63 downto 37));

    when 38 =>

        wb_sll := v64(25 downto 0) & X"000000000" & "00";

        wb_srl := X"000000000" & "00" & v64(63 downto 38);

        wb_sra := (msk64(63 downto 26) & v64(63 downto 38));

    when 39 =>

        wb_sll := v64(24 downto 0) & X"000000000" & "000";

        wb_srl := X"000000000" & "000" & v64(63 downto 39);

        wb_sra := (msk64(63 downto 25) & v64(63 downto 39));

    when 40 =>

        wb_sll := v64(23 downto 0) & X"0000000000";

        wb_srl := X"0000000000" & v64(63 downto 40);

        wb_sra := (msk64(63 downto 24) & v64(63 downto 40));

    when 41 =>

        wb_sll := v64(22 downto 0) & X"0000000000" & "0";

        wb_srl := X"0000000000" & "0" & v64(63 downto 41);

        wb_sra := (msk64(63 downto 23) & v64(63 downto 41));

    when 42 =>

        wb_sll := v64(21 downto 0) & X"0000000000" & "00";

        wb_srl := X"0000000000" & "00" & v64(63 downto 42);

        wb_sra := (msk64(63 downto 22) & v64(63 downto 42));

    when 43 =>

        wb_sll := v64(20 downto 0) & X"0000000000" & "000";

        wb_srl := X"0000000000" & "000" & v64(63 downto 43);

        wb_sra := (msk64(63 downto 21) & v64(63 downto 43));

    when 44 =>

        wb_sll := v64(19 downto 0) & X"00000000000";

        wb_srl := X"00000000000" & v64(63 downto 44);

        wb_sra := (msk64(63 downto 20) & v64(63 downto 44));

    when 45 =>

        wb_sll := v64(18 downto 0) & X"00000000000" & "0";

        wb_srl := X"00000000000" & "0" & v64(63 downto 45);

        wb_sra := (msk64(63 downto 19) & v64(63 downto 45));

    when 46 =>

        wb_sll := v64(17 downto 0) & X"00000000000" & "00";

        wb_srl := X"00000000000" & "00" & v64(63 downto 46);

        wb_sra := (msk64(63 downto 18) & v64(63 downto 46));

    when 47 =>

        wb_sll := v64(16 downto 0) & X"00000000000" & "000";

        wb_srl := X"00000000000" & "000" & v64(63 downto 47);

        wb_sra := (msk64(63 downto 17) & v64(63 downto 47));

    when 48 =>

        wb_sll := v64(15 downto 0) & X"000000000000";

        wb_srl := X"000000000000" & v64(63 downto 48);

        wb_sra := (msk64(63 downto 16) & v64(63 downto 48));

    when 49 =>

        wb_sll := v64(14 downto 0) & X"000000000000" & "0";

        wb_srl := X"000000000000" & "0" & v64(63 downto 49);

        wb_sra := (msk64(63 downto 15) & v64(63 downto 49));

    when 50 =>

        wb_sll := v64(13 downto 0) & X"000000000000" & "00";

        wb_srl := X"000000000000" & "00" & v64(63 downto 50);

        wb_sra := (msk64(63 downto 14) & v64(63 downto 50));

    when 51 =>

        wb_sll := v64(12 downto 0) & X"000000000000" & "000";

        wb_srl := X"000000000000" & "000" & v64(63 downto 51);

        wb_sra := (msk64(63 downto 13) & v64(63 downto 51));

    when 52 =>

        wb_sll := v64(11 downto 0) & X"0000000000000";

        wb_srl := X"0000000000000" & v64(63 downto 52);

        wb_sra := (msk64(63 downto 12) & v64(63 downto 52));

    when 53 =>

        wb_sll := v64(10 downto 0) & X"0000000000000" & "0";

        wb_srl := X"0000000000000" & "0" & v64(63 downto 53);

        wb_sra := (msk64(63 downto 11) & v64(63 downto 53));

    when 54 =>

        wb_sll := v64(9 downto 0) & X"0000000000000" & "00";

        wb_srl := X"0000000000000" & "00" & v64(63 downto 54);

        wb_sra := (msk64(63 downto 10) & v64(63 downto 54));

    when 55 =>

        wb_sll := v64(8 downto 0) & X"0000000000000" & "000";

        wb_srl := X"0000000000000" & "000" & v64(63 downto 55);

        wb_sra := (msk64(63 downto 9) & v64(63 downto 55));

    when 56 =>

        wb_sll := v64(7 downto 0) & X"00000000000000";

        wb_srl := X"00000000000000" & v64(63 downto 56);

        wb_sra := (msk64(63 downto 8) & v64(63 downto 56));

    when 57 =>

        wb_sll := v64(6 downto 0) & X"00000000000000" & "0";

        wb_srl := X"00000000000000" & "0" & v64(63 downto 57);

        wb_sra := (msk64(63 downto 7) & v64(63 downto 57));

    when 58 =>

        wb_sll := v64(5 downto 0) & X"00000000000000" & "00";

        wb_srl := X"00000000000000" & "00" & v64(63 downto 58);

        wb_sra := (msk64(63 downto 6) & v64(63 downto 58));

    when 59 =>

        wb_sll := v64(4 downto 0) & X"00000000000000" & "000";

        wb_srl := X"00000000000000" & "000" & v64(63 downto 59);

        wb_sra := (msk64(63 downto 5) & v64(63 downto 59));

    when 60 =>

        wb_sll := v64(3 downto 0) & X"000000000000000";

        wb_srl := X"000000000000000" & v64(63 downto 60);

        wb_sra := (msk64(63 downto 4) & v64(63 downto 60));

    when 61 =>

        wb_sll := v64(2 downto 0) & X"000000000000000" & "0";

        wb_srl := X"000000000000000" & "0" & v64(63 downto 61);

        wb_sra := (msk64(63 downto 3) & v64(63 downto 61));

    when 62 =>

        wb_sll := v64(1 downto 0) & X"000000000000000" & "00";

        wb_srl := X"000000000000000" & "00" & v64(63 downto 62);

        wb_sra := (msk64(63 downto 2) & v64(63 downto 62));

    when 63 =>

        wb_sll := v64(0) & X"000000000000000" & "000";

        wb_srl := X"000000000000000" & "000" & v64(63);

        wb_sra := (msk64(63 downto 1) & v64(63));

    end case;

    case shift32 is

    when 0 =>

        wb_srlw := v32;

        wb_sraw := (msk32(63 downto 32) & v32);

    when 1 =>

        wb_srlw := "0" & v32(31 downto 1);

        wb_sraw := (msk32(63 downto 31) & v32(31 downto 1));

    when 2 =>

        wb_srlw := "00" & v32(31 downto 2);

        wb_sraw := (msk32(63 downto 30) & v32(31 downto 2));

    when 3 =>

        wb_srlw := "000" & v32(31 downto 3);

        wb_sraw := (msk32(63 downto 29) & v32(31 downto 3));

    when 4 =>

        wb_srlw := X"0" & v32(31 downto 4);

        wb_sraw := (msk32(63 downto 28) & v32(31 downto 4));

    when 5 =>

        wb_srlw := X"0" & "0" & v32(31 downto 5);

        wb_sraw := (msk32(63 downto 27) & v32(31 downto 5));

    when 6 =>

        wb_srlw := X"0" & "00" & v32(31 downto 6);

        wb_sraw := (msk32(63 downto 26) & v32(31 downto 6));

    when 7 =>

        wb_srlw := X"0" & "000" & v32(31 downto 7);

        wb_sraw := (msk32(63 downto 25) & v32(31 downto 7));

    when 8 =>

        wb_srlw := X"00" & v32(31 downto 8);

        wb_sraw := (msk32(63 downto 24) & v32(31 downto 8));

    when 9 =>

        wb_srlw := X"00" & "0" & v32(31 downto 9);

        wb_sraw := (msk32(63 downto 23) & v32(31 downto 9));

    when 10 =>

        wb_srlw := X"00" & "00" & v32(31 downto 10);

        wb_sraw := (msk32(63 downto 22) & v32(31 downto 10));

    when 11 =>

        wb_srlw := X"00" & "000" & v32(31 downto 11);

        wb_sraw := (msk32(63 downto 21) & v32(31 downto 11));

    when 12 =>

        wb_srlw := X"000" & v32(31 downto 12);

        wb_sraw := (msk32(63 downto 20) & v32(31 downto 12));

    when 13 =>

        wb_srlw := X"000" & "0" & v32(31 downto 13);

        wb_sraw := (msk32(63 downto 19) & v32(31 downto 13));

    when 14 =>

        wb_srlw := X"000" & "00" & v32(31 downto 14);

        wb_sraw := (msk32(63 downto 18) & v32(31 downto 14));

    when 15 =>

        wb_srlw := X"000" & "000" & v32(31 downto 15);

        wb_sraw := (msk32(63 downto 17) & v32(31 downto 15));

    when 16 =>

        wb_srlw := X"0000" & v32(31 downto 16);

        wb_sraw := (msk32(63 downto 16) & v32(31 downto 16));

    when 17 =>

        wb_srlw := X"0000" & "0" & v32(31 downto 17);

        wb_sraw := (msk32(63 downto 15) & v32(31 downto 17));

    when 18 =>

        wb_srlw := X"0000" & "00" & v32(31 downto 18);

        wb_sraw := (msk32(63 downto 14) & v32(31 downto 18));

    when 19 =>

        wb_srlw := X"0000" & "000" & v32(31 downto 19);

        wb_sraw := (msk32(63 downto 13) & v32(31 downto 19));

    when 20 =>

        wb_srlw := X"00000" & v32(31 downto 20);

        wb_sraw := (msk32(63 downto 12) & v32(31 downto 20));

    when 21 =>

        wb_srlw := X"00000" & "0" & v32(31 downto 21);

        wb_sraw := (msk32(63 downto 11) & v32(31 downto 21));

    when 22 =>

        wb_srlw := X"00000" & "00" & v32(31 downto 22);

        wb_sraw := (msk32(63 downto 10) & v32(31 downto 22));

    when 23 =>

        wb_srlw := X"00000" & "000" & v32(31 downto 23);

        wb_sraw := (msk32(63 downto 9) & v32(31 downto 23));

    when 24 =>

        wb_srlw := X"000000" & v32(31 downto 24);

        wb_sraw := (msk32(63 downto 8) & v32(31 downto 24));

    when 25 =>

        wb_srlw := X"000000" & "0" & v32(31 downto 25);

        wb_sraw := (msk32(63 downto 7) & v32(31 downto 25));

    when 26 =>

        wb_srlw := X"000000" & "00" & v32(31 downto 26);

        wb_sraw := (msk32(63 downto 6) & v32(31 downto 26));

    when 27 =>

        wb_srlw := X"000000" & "000" & v32(31 downto 27);

        wb_sraw := (msk32(63 downto 5) & v32(31 downto 27));

    when 28 =>

        wb_srlw := X"0000000" & v32(31 downto 28);

        wb_sraw := (msk32(63 downto 4) & v32(31 downto 28));

    when 29 =>

        wb_srlw := X"0000000" & "0" & v32(31 downto 29);

        wb_sraw := (msk32(63 downto 3) & v32(31 downto 29));

    when 30 =>

        wb_srlw := X"0000000" & "00" & v32(31 downto 30);

        wb_sraw := (msk32(63 downto 2) & v32(31 downto 30));

    when 31 =>

        wb_srlw := X"0000000" & "000" & v32(31 downto 31);

        wb_sraw := (msk32(63 downto 1) & v32(31 downto 31));

    end case;

    o_sll <= wb_sll;

    o_sllw(31 downto 0) <= wb_sll(31 downto 0);

    o_sllw(63 downto 32) <= (others => wb_sll(31));

    o_srl <= wb_srl;

    o_sra <= wb_sra;

    o_srlw <= X"00000000" & wb_srlw;

    o_sraw <= wb_sraw;

  end process;

end;