1 ------------------------------------------------------------------------------
   2 ------------------------------------------------------------------------------
   3 -- This file is part of 'Finite Field Arithmetic', aka 'FFA'.               --
   4 --                                                                          --
   5 -- (C) 2019 Stanislav Datskovskiy ( www.loper-os.org )                      --
   6 -- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html     --
   7 --                                                                          --
   8 -- You do not have, nor can you ever acquire the right to use, copy or      --
   9 -- distribute this software ; Should you use this software for any purpose, --
  10 -- or copy and distribute it to anyone or in any manner, you are breaking   --
  11 -- the laws of whatever soi-disant jurisdiction, and you promise to         --
  12 -- continue doing so for the indefinite future. In any case, please         --
  13 -- always : read and understand any software ; verify any PGP signatures    --
  14 -- that you use - for any purpose.                                          --
  15 --                                                                          --
  16 -- See also http://trilema.com/2015/a-new-software-licensing-paradigm .     --
  17 ------------------------------------------------------------------------------
  18 ------------------------------------------------------------------------------
  19 
  20 with FZ_Type; use FZ_Type;
  21 
  22 
  23 package FZ_Mul is
  24    
  25    pragma Pure;
  26    
  27    -- Karatsuba Threshhold - at or below this many Words, we use Comba mult.
  28    Karatsuba_Thresh : constant Indices := 8;
  29    
  30    -- Multiply. (CAUTION: UNBUFFERED)
  31    procedure FZ_Multiply_Unbuffered(X     : in  FZ;
  32                                     Y     : in  FZ;
  33                                     XY    : out FZ);
  34    pragma Inline_Always(FZ_Multiply_Unbuffered);
  35    
  36    -- Comba's multiplier. (CAUTION: UNBUFFERED)
  37    procedure FZ_Mul_Comba(X     : in  FZ;
  38                           Y     : in  FZ;
  39                           XY    : out FZ);
  40    pragma Inline_Always(FZ_Mul_Comba);
  41    
  42    -- Karatsuba's Multiplier. (CAUTION: UNBUFFERED)
  43    procedure Mul_Karatsuba(X  : in  FZ;
  44                            Y  : in  FZ;
  45                            XY : out FZ)
  46      with Pre => X'Length = Y'Length and
  47      XY'Length = (X'Length + Y'Length) and
  48      X'Length mod 2 = 0;
  49    -- CAUTION: Inlining prohibited for Mul_Karatsuba !
  50    
  51    -- Multiplier. Preserves the inputs.
  52    procedure FZ_Multiply_Buffered(X     : in  FZ;
  53                                   Y     : in  FZ;
  54                                   XY_Lo : out FZ;
  55                                   XY_Hi : out FZ);
  56    pragma Inline_Always(FZ_Multiply_Buffered);
  57    
  58 end FZ_Mul;