raw
ffa_ch3_shifts.kv       1 ------------------------------------------------------------------------------
ffa_ch3_shifts.kv       2 ------------------------------------------------------------------------------
ffa_ch3_shifts.kv       3 -- This file is part of 'Finite Field Arithmetic', aka 'FFA'.               --
ffa_ch3_shifts.kv       4 --                                                                          --
ffa_ch14_barrett.kv     5 -- (C) 2018 Stanislav Datskovskiy ( www.loper-os.org )                      --
ffa_ch3_shifts.kv       6 -- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html     --
ffa_ch3_shifts.kv       7 --                                                                          --
ffa_ch3_shifts.kv       8 -- You do not have, nor can you ever acquire the right to use, copy or      --
ffa_ch3_shifts.kv       9 -- distribute this software ; Should you use this software for any purpose, --
ffa_ch3_shifts.kv      10 -- or copy and distribute it to anyone or in any manner, you are breaking   --
ffa_ch3_shifts.kv      11 -- the laws of whatever soi-disant jurisdiction, and you promise to         --
ffa_ch3_shifts.kv      12 -- continue doing so for the indefinite future. In any case, please         --
ffa_ch3_shifts.kv      13 -- always : read and understand any software ; verify any PGP signatures    --
ffa_ch3_shifts.kv      14 -- that you use - for any purpose.                                          --
ffa_ch3_shifts.kv      15 --                                                                          --
ffa_ch3_shifts.kv      16 -- See also http://trilema.com/2015/a-new-software-licensing-paradigm .     --
ffa_ch3_shifts.kv      17 ------------------------------------------------------------------------------
ffa_ch3_shifts.kv      18 ------------------------------------------------------------------------------
ffa_ch3_shifts.kv      19 
ffa_ch3_shifts.kv      20 with W_Shifts; use W_Shifts;
ffa_ch3_shifts.kv      21 
ffa_ch3_shifts.kv      22 
ffa_ch3_shifts.kv      23 package body FZ_Shift is
ffa_ch3_shifts.kv      24    
ffa_ch3_shifts.kv      25    --------------------------------------------------------------
ffa_ch3_shifts.kv      26    -- Shift Right
ffa_ch3_shifts.kv      27    --------------------------------------------------------------
ffa_ch3_shifts.kv      28    
ffa_ch3_shifts.kv      29    -- ShiftedN := N >> Count (with Overflow Input and Output)
ffa_ch14_barrett.kv    30    -- WARNING: OF_in MUST be of valid bit-width for the shift!
ffa_ch3_shifts.kv      31    procedure FZ_ShiftRight_O_I(N        : in  FZ;
ffa_ch3_shifts.kv      32                                ShiftedN : out FZ;
ffa_ch3_shifts.kv      33                                Count    : in  WBit_Index;
ffa_ch3_shifts.kv      34                                Overflow : out Word;
ffa_ch3_shifts.kv      35                                OF_in    : in  Word) is
ffa_ch3_shifts.kv      36       Ni    : Word;
ffa_ch3_shifts.kv      37       Carry : Word := OF_in;
ffa_ch3_shifts.kv      38    begin
ffa_ch3_shifts.kv      39       for i in reverse N'Range loop
ffa_ch3_shifts.kv      40          Ni := N(i);
ffa_ch3_shifts.kv      41          ShiftedN(i) := Shift_Right(Ni, Count) or Carry;
ffa_ch3_shifts.kv      42          Carry := Shift_Left(Ni, Bitness - Count);
ffa_ch3_shifts.kv      43       end loop;
ffa_ch3_shifts.kv      44       Overflow := Carry;
ffa_ch3_shifts.kv      45    end FZ_ShiftRight_O_I;
ffa_ch3_shifts.kv      46    
ffa_ch3_shifts.kv      47    
ffa_ch3_shifts.kv      48    -- ShiftedN := N >> Count (with Overflow Output only)
ffa_ch3_shifts.kv      49    procedure FZ_ShiftRight_O(N        : in  FZ;
ffa_ch3_shifts.kv      50                              ShiftedN : out FZ;
ffa_ch3_shifts.kv      51                              Count    : in  WBit_Index;
ffa_ch3_shifts.kv      52                              Overflow : out Word) is
ffa_ch3_shifts.kv      53    begin
ffa_ch3_shifts.kv      54       FZ_ShiftRight_O_I(N, ShiftedN, Count, Overflow, 0);
ffa_ch3_shifts.kv      55    end FZ_ShiftRight_O;
ffa_ch3_shifts.kv      56    
ffa_ch3_shifts.kv      57    
ffa_ch3_shifts.kv      58    -- ShiftedN := N >> Count (no Overflow output or input)
ffa_ch3_shifts.kv      59    procedure FZ_ShiftRight(N        : in  FZ;
ffa_ch3_shifts.kv      60                            ShiftedN : out FZ;
ffa_ch3_shifts.kv      61                            Count    : in  WBit_Index) is
ffa_ch3_shifts.kv      62       Overflow : Word;
ffa_ch3_shifts.kv      63       pragma Unreferenced(Overflow);
ffa_ch3_shifts.kv      64    begin
ffa_ch3_shifts.kv      65       FZ_ShiftRight_O_I(N, ShiftedN, Count, Overflow, 0);
ffa_ch3_shifts.kv      66    end FZ_ShiftRight;
ffa_ch3_shifts.kv      67    
ffa_ch3_shifts.kv      68    --------------------------------------------------------------
ffa_ch3_shifts.kv      69    -- Shift Left
ffa_ch3_shifts.kv      70    --------------------------------------------------------------
ffa_ch3_shifts.kv      71    
ffa_ch3_shifts.kv      72    -- ShiftedN := N << Count (with Overflow Input and Output)
ffa_ch14_barrett.kv    73    -- WARNING: OF_in MUST be of valid bit-width for the shift!
ffa_ch3_shifts.kv      74    procedure FZ_ShiftLeft_O_I(N        : in  FZ;
ffa_ch3_shifts.kv      75                               ShiftedN : out FZ;
ffa_ch3_shifts.kv      76                               Count    : in  WBit_Index;
ffa_ch3_shifts.kv      77                               Overflow : out Word;
ffa_ch3_shifts.kv      78                               OF_in    : in  Word) is
ffa_ch3_shifts.kv      79       Ni    : Word;
ffa_ch3_shifts.kv      80       Carry : Word := OF_in;
ffa_ch3_shifts.kv      81    begin
ffa_ch3_shifts.kv      82       for i in N'Range loop
ffa_ch3_shifts.kv      83          Ni := N(i);
ffa_ch3_shifts.kv      84          ShiftedN(i) := Shift_Left(Ni, Count) or Carry;
ffa_ch3_shifts.kv      85          Carry := Shift_Right(Ni, Bitness - Count);
ffa_ch3_shifts.kv      86       end loop;
ffa_ch3_shifts.kv      87       Overflow := Carry;
ffa_ch3_shifts.kv      88    end FZ_ShiftLeft_O_I;
ffa_ch3_shifts.kv      89    
ffa_ch3_shifts.kv      90    
ffa_ch3_shifts.kv      91    -- ShiftedN := N << Count (with Overflow Output only)
ffa_ch3_shifts.kv      92    procedure FZ_ShiftLeft_O(N        : in  FZ;
ffa_ch3_shifts.kv      93                             ShiftedN : out FZ;
ffa_ch3_shifts.kv      94                             Count    : in  WBit_Index;
ffa_ch3_shifts.kv      95                             Overflow : out Word) is
ffa_ch3_shifts.kv      96    begin
ffa_ch3_shifts.kv      97       FZ_ShiftLeft_O_I(N, ShiftedN, Count, Overflow, 0);
ffa_ch3_shifts.kv      98    end FZ_ShiftLeft_O;
ffa_ch3_shifts.kv      99    
ffa_ch3_shifts.kv     100    
ffa_ch3_shifts.kv     101    -- ShiftedN := N << Count (no Overflow output or input)
ffa_ch3_shifts.kv     102    procedure FZ_ShiftLeft(N        : in  FZ;
ffa_ch3_shifts.kv     103                           ShiftedN : out FZ;
ffa_ch3_shifts.kv     104                           Count    : in  WBit_Index) is
ffa_ch3_shifts.kv     105       Overflow : Word;
ffa_ch3_shifts.kv     106       pragma Unreferenced(Overflow);
ffa_ch3_shifts.kv     107    begin
ffa_ch3_shifts.kv     108       FZ_ShiftLeft_O_I(N, ShiftedN, Count, Overflow, 0);
ffa_ch3_shifts.kv     109    end FZ_ShiftLeft;
ffa_ch3_shifts.kv     110    
ffa_ch3_shifts.kv     111 end FZ_Shift;