[fpc-devel] ROL/ROR with Carry

[Sven Barth]

Hello together!

Considering that jamie philbrook has given up on his feature request ( 
https://bugs.freepascal.org/view.php?id=38341 ) rather quickly and that 
it had been my idea for him to open that bug report I'd like to discuss 
this here.

So the idea is to add support for ROL/ROR with Carry support as the 
current Rol*/Ror* functions don't support that. Florian then said that 
he's open to suggestions under some restrictions. Considering that the 
current Rol*/Ror* intrinsics aren't available for all platforms as 
intrinsics either, but as functions then, this could be done to support 
CPUs without suitable Carry support as well. And the code snippet that 
jamie showed would be a nice base:

=== code begin ===

Function ROLByteWithCarry(Const AByte:Byte; Var ACarry:Boolean):Byte;Inline;
var
   LocalIn:Boolean;
  Begin
   LocalIN := Acarry;
   ACarry := ShortInt(Abyte) < 0;
   Result := (AByte shl 1);
   IF LocalIn then Result := Result or 1;
  End;

=== code end ===

Am I missing something?

Regards,
Sven