---

---

 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 Words; use Words;
 21 with FZ_Type; use FZ_Type;
 22 
 23 
 24 package FZ_Basic is
 25  
 26  pragma Pure;
 27  
 28  -- Determine the Bitness of N
 29  function FZ_Bitness(N : in FZ) return Bit_Count;
 30  pragma Inline_Always(FZ_Bitness);
 31  
 32  -- Determine the Bitness of the given FZ's Length
 33  function FZ_Bitness_Log2(N : in FZ) return Positive;
 34  pragma Inline_Always(FZ_Bitness_Log2);
 35  
 36  -- N := 0
 37  procedure FZ_Clear(N : out FZ);
 38  pragma Inline_Always(FZ_Clear);
 39  
 40  -- Set given FZ to a given truth value
 41  procedure WBool_To_FZ(V : in WBool; N : out FZ);
 42  pragma Inline_Always(WBool_To_FZ);
 43  
 44  -- First word of N := Source
 45  procedure FZ_Set_Head(N : out FZ; Source : in Word);
 46  pragma Inline_Always(FZ_Set_Head);
 47  
 48  -- First word of N
 49  function FZ_Get_Head(N : in FZ) return Word;
 50  pragma Inline_Always(FZ_Get_Head);
 51  
 52  -- Exchange X and Y
 53  procedure FZ_Swap(X : in out FZ; Y : in out FZ);
 54  pragma Inline_Always(FZ_Swap);
 55  
 56  -- Constant-time MUX: Sel = 0: Result := X; Sel = 1: Result := Y
 57  procedure FZ_Mux(X : in FZ; Y : in FZ; Result : out FZ; Sel : in WBool);
 58  pragma Inline_Always(FZ_Mux);
 59  
 60 end FZ_Basic;