------------------------------------------------------------------------------ ------------------------------------------------------------------------------ -- This file is part of 'Finite Field Arithmetic', aka 'FFA'. -- -- -- -- (C) 2017 Stanislav Datskovskiy ( www.loper-os.org ) -- -- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html -- -- -- -- You do not have, nor can you ever acquire the right to use, copy or -- -- distribute this software ; Should you use this software for any purpose, -- -- or copy and distribute it to anyone or in any manner, you are breaking -- -- the laws of whatever soi-disant jurisdiction, and you promise to -- -- continue doing so for the indefinite future. In any case, please -- -- always : read and understand any software ; verify any PGP signatures -- -- that you use - for any purpose. -- -- -- -- See also http://trilema.com/2015/a-new-software-licensing-paradigm . -- ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ with FZ_Type; use FZ_Type; package FZ_Mul is pragma Pure; -- Karatsuba Threshhold - at or below this many words, we use Comba mult. Karatsuba_Thresh : constant Indices := 8; -- Multiply. (CAUTION: UNBUFFERED) procedure FZ_Multiply(X : in FZ; Y : in FZ; XY : out FZ); pragma Precondition(X'Length = Y'Length and XY'Length = (X'Length + Y'Length)); -- Comba's multiplier. (CAUTION: UNBUFFERED) procedure FZ_Mul_Comba(X : in FZ; Y : in FZ; XY : out FZ); pragma Precondition(X'Length = Y'Length and XY'Length = (X'Length + Y'Length)); -- Karatsuba's Multiplier. (CAUTION: UNBUFFERED) procedure Mul_Karatsuba(X : in FZ; Y : in FZ; XY : out FZ); pragma Precondition(X'Length = Y'Length and XY'Length = (X'Length + Y'Length) and X'Length mod 2 = 0); -- CAUTION: Inlining prohibited for Mul_Karatsuba ! -- Multiplier. Preserves the inputs. procedure FZ_Mult(X : in FZ; Y : in FZ; XY_Lo : out FZ; XY_Hi : out FZ); pragma Precondition(X'Length = Y'Length and XY_Lo'Length = XY_Hi'Length and XY_Lo'Length = ((X'Length + Y'Length) / 2)); end FZ_Mul;