Author: Tim Foden
Date: 01:48:03 06/20/02
Go up one level in this thread
On June 18, 2002 at 13:14:28, Gerd Isenberg wrote:
>On June 18, 2002 at 12:15:09, Adriano Bedeschi de Souza wrote:
>
>>Could someone help me with LSB (MSB) and POPCOUNT optimization?
>>
>>thx,
>>Bedeschi
>
>some sample source code for msc6 with sone inline asm:
>
>LSB with reset found bit:
>
>// precondition: bb not null
>__forceinline unsigned int BitSearchAndReset(BitBoard &bb)
>{
>#ifdef _M_IX86
> __asm
> {
> mov edx, [bb]
> bsf eax, [edx+4]
> xor eax, 32
> bsf eax, [edx]
> btr [edx],eax
> }
I'm afriad the above code won't work as intended, as the "btr [edx], eax" line
will always affect the low 32 bits and never the high 32 bits.
Cheers, Tim.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.