Subversion Repositories rv01_riscv_core

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

--                                                             --

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

--                                                             --

-- Copyright (C) 2015 Stefano Tonello                          --

--                                                             --

-- This source file may be used and distributed without        --

-- restriction provided that this copyright statement is not   --

-- removed from the file and that any derivative work contains --

-- the original copyright notice and the associated disclaimer.--

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-- THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY         --

-- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   --

-- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   --

-- FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      --

-- OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         --

-- INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    --

-- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   --

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

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

-- Divider shifting functions

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

library IEEE;

use IEEE.std_logic_1164.all;

use IEEE.numeric_std.all;

package RV01_DIV_FUNCS_PKG is

  function div_shift_left32(SI : unsigned;SHFT : integer range 0 to 32) return unsigned;

  function div_shift_right32(SI : unsigned;SHFT : integer range 0 to 32) return unsigned;

end package;

package body RV01_DIV_FUNCS_PKG is

  function div_shift_left32(SI : unsigned;SHFT : integer range 0 to 32) return unsigned is

    variable SO : unsigned(SI'HIGH downto SI'LOW);

  begin

    case SHFT is

      when 0  => SO := SI sll 0;

      when 1  => SO := SI sll 1;

      when 2  => SO := SI sll 2;

      when 3  => SO := SI sll 3;

      when 4  => SO := SI sll 4;

      when 5  => SO := SI sll 5;

      when 6  => SO := SI sll 6;

      when 7  => SO := SI sll 7;

      when 8  => SO := SI sll 8;

      when 9  => SO := SI sll 9;

      when 10 => SO := SI sll 10;

      when 11 => SO := SI sll 11;

      when 12 => SO := SI sll 12;

      when 13 => SO := SI sll 13;

      when 14 => SO := SI sll 14;

      when 15 => SO := SI sll 15;

      when 16 => SO := SI sll 16;

      when 17 => SO := SI sll 17;

      when 18 => SO := SI sll 18;

      when 19 => SO := SI sll 19;

      when 20 => SO := SI sll 20;

      when 21 => SO := SI sll 21;

      when 22 => SO := SI sll 22;

      when 23 => SO := SI sll 23;

      when 24 => SO := SI sll 24;

      when 25 => SO := SI sll 25;

      when 26 => SO := SI sll 26;

      when 27 => SO := SI sll 27;

      when 28 => SO := SI sll 28;

      when 29 => SO := SI sll 29;

      when 30 => SO := SI sll 30;

      when 31 => SO := SI sll 31;

      when others => SO := SI sll 32;

    end case;

    return(SO);

  end function;

  function div_shift_right32(SI : unsigned;SHFT : integer range 0 to 32) return unsigned is

    variable SO : unsigned(SI'HIGH downto SI'LOW);

  begin

    case SHFT is

      when 0  => SO := SI srl 0;

      when 1  => SO := SI srl 1;

      when 2  => SO := SI srl 2;

      when 3  => SO := SI srl 3;

      when 4  => SO := SI srl 4;

      when 5  => SO := SI srl 5;

      when 6  => SO := SI srl 6;

      when 7  => SO := SI srl 7;

      when 8  => SO := SI srl 8;

      when 9  => SO := SI srl 9;

      when 10 => SO := SI srl 10;

      when 11 => SO := SI srl 11;

      when 12 => SO := SI srl 12;

      when 13 => SO := SI srl 13;

      when 14 => SO := SI srl 14;

      when 15 => SO := SI srl 15;

      when 16 => SO := SI srl 16;

      when 17 => SO := SI srl 17;

      when 18 => SO := SI srl 18;

      when 19 => SO := SI srl 19;

      when 20 => SO := SI srl 20;

      when 21 => SO := SI srl 21;

      when 22 => SO := SI srl 22;

      when 23 => SO := SI srl 23;

      when 24 => SO := SI srl 24;

      when 25 => SO := SI srl 25;

      when 26 => SO := SI srl 26;

      when 27 => SO := SI srl 27;

      when 28 => SO := SI srl 28;

      when 29 => SO := SI srl 29;

      when 30 => SO := SI srl 30;

      when 31 => SO := SI srl 31;

      when others => SO := SI srl 32;

    end case;

    return(SO);

  end function;

end package body;