File : fz_cmp.adb

   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 W_Pred;   use W_Pred;
  21 with FZ_Arith; use FZ_Arith;
  22 
  23 
  24 package body FZ_Cmp is
  25    
  26    ---------------------------------------------
  27    -- Arithmetical Predicate Operations on FZ --
  28    ---------------------------------------------
  29    
  30    -- 1 iff X == Y (branch-free); else 0
  31    function FZ_EqP(X : in FZ; Y : in FZ) return WBool is
  32       A : WBool := 1;
  33    begin
  34       for i in X'Range loop
  35          A := A and W_EqP(X(i), Y(i));
  36       end loop;
  37       return A;
  38    end FZ_EqP;
  39    
  40    
  41    -- 1 iff X < Y (branch-free); else 0
  42    function FZ_LessThanP(X : in FZ; Y : in FZ) return WBool is
  43       Scratch : FZ(X'Range);
  44       Borrow  : WBool := 0;
  45    begin
  46       FZ_Sub(X, Y, Scratch, Borrow);
  47       return Borrow;
  48    end FZ_LessThanP;
  49    
  50    
  51    -- 1 iff X > Y (branch-free); else 0
  52    function FZ_GreaterThanP(X : in FZ; Y: in FZ) return WBool is
  53       Scratch : FZ(X'Range);
  54       Borrow  : WBool := 0;
  55    begin
  56       FZ_Sub(Y, X, Scratch, Borrow);
  57       return Borrow;
  58    end FZ_GreaterThanP;
  59    
  60 end FZ_Cmp;