Author: Gerd Isenberg
Date: 23:48:09 09/29/05
Go up one level in this thread
On September 29, 2005 at 18:45:15, Dezhi Zhao wrote:
>Here it is:
Thanks,
looks fine. Compact code. Perfect register usage - only the fastcall parameter
registers rcx, rdx and the the "return"-register rax are used. No memory access.
And a nice rearrangement of the three last source lines.
Otoh, there are a lot dependencies - i prefere using one additional register and
some more "parallel" work. In "reality", those leaf-routines are inlined with
others and instruction scheduling may be a bit more independent.
Gerd
>
>; Listing generated by Microsoft (R) Optimizing Compiler Version 14.00.50727.26
>
>include listing.inc
>
>INCLUDELIB OLDNAMES
>
>PUBLIC ?rightUpAttacks@@YA_K_K0@Z ; rightUpAttacks
>; Function compile flags: /Ogtpy
>; File c:\documents and settings\administrator\my documents\visual studio
>2005\projects\x64\x64\x64.cpp
>; COMDAT ?rightUpAttacks@@YA_K_K0@Z
>_TEXT SEGMENT
>deo$ = 8
>pro$ = 16
>?rightUpAttacks@@YA_K_K0@Z PROC ; rightUpAttacks, COMDAT
>
>; 11 : BitBoard notA = 0xfefefefefefefefe;
>; 12 :
>; 13 : pro = pro & notA;
>
> mov rax, -72340172838076674 ; fefefefefefefefeH
> and rdx, rax
>
>; 14 : deo |= pro & (deo << 9);
>
> mov rax, rcx
> shl rax, 9
> and rax, rdx
> or rcx, rax
>
>; 15 : pro = pro & (pro << 9);
>
> mov rax, rdx
> shl rax, 9
> and rdx, rax
>
>; 16 : deo |= pro & (deo << 18);
>
> mov rax, rcx
> shl rax, 18
> and rax, rdx
> or rcx, rax
>
>; 17 : pro = pro & (pro << 18);
>; 18 : deo |= pro & (deo << 36);
>; 19 : return (deo << 9) & notA;
>
> mov rax, rcx
> shl rax, 18
> and rax, rdx
> shl rax, 18
> and rax, rdx
> or rax, rcx
> mov rcx, -141289400074369 ; ffff7f7f7f7f7f7fH
> and rax, rcx
> shl rax, 9
>
>; 20 : }
>
> ret 0
>?rightUpAttacks@@YA_K_K0@Z ENDP ; rightUpAttacks
>_TEXT ENDS
>
>
>On September 29, 2005 at 14:16:06, Gerd Isenberg wrote:
>
>>Dezhi, can you please post some x86-64 assembly of this routine?
>>
>>Thanks,
>>Gerd
>>
>>
>>typedef unsigned __int64 BitBoard;
>>
>>BitBoard notA = 0xfefefefefefefefe;
>>
>>BitBoard rightUpAttacks(BitBoard deo, BitBoard pro) {
>> pro = pro & notA;
>> deo |= pro & (deo << 9);
>> pro = pro & (pro << 9);
>> deo |= pro & (deo << 18);
>> pro = pro & (pro << 18);
>> deo |= pro & (deo << 36);
>> return (deo << 9) & notA;
>>}
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