[SOLVED] Improvement of procedure TSHA512Base.Update

[lagprogramming]

packages/fcl-hash/src/fpsha512.pp has

Code: Pascal  [Select][+][-]

1. procedure TSHA512Base.Update(PBuf: PByte; Size: UInt32);
2. var
3.   Len: UInt32;
4. begin
5.   Inc(TotalLength, Int64(UInt32(Size)) * 8);
6.   while Size > 0 do
7.   begin
8.     Len:=Sizeof(Buffer)-Index;
9.     if Len <= UInt32(Size) then
10.     begin
11.       Move(PBuf^, Buffer[Index], Len);
12.       Dec(Size, Len);
13.       Inc(PBuf, Len);
14.       Compress;
15.       Self.Index := 0;
16.     end else
17.     begin
18.       Move(PBuf^, Buffer[Index], Size);
19.       Inc(Self.Index, Size);
20.       Size := 0;
21.     end;
22.   end;
23. end;

In order to exit the loop the original code sets a zero value to Size. The attached patch changes the line "Size := 0;" with "Break;". In addition to increased readability, the CPU will avoid a failed prediction of the "Size > 0" condition.

[AlexTP]

Posted to https://gitlab.com/freepascal.org/fpc/source/-/issues/40435

[abouchez]

Sounds like a non-improvement to me.

Performance would be identical for sure, and readability not enhanced to my taste.

[AlexTP]

Anyway, I keep posting suggestions from 'lagprogramming'. He does minor work, but useful.