Author: Larry Griffiths
Date: 10:49:50 08/09/00
Go up one level in this thread
On August 09, 2000 at 13:22:27, James Robertson wrote:
>On August 08, 2000 at 23:33:49, Larry Griffiths wrote:
>
>>I use the Read time stamp counter in my program sometimes, it looks like this...
>>
>>
>>#ifdef INCLUDE_TIMERS
>>#define StartTimer(start)\
>> {\
>> asm\
>> {\
>> db 0fh,31h;\
>> mov dword ptr start+4,EDX;\
>> mov dword ptr start,EAX;\
>> }\
>> }
>>#define StopTimer(stop)\
>> {\
>> asm\
>> {\
>> db 0fh,31h;\
>> mov dword ptr stop+4,EDX;\
>> mov dword ptr stop,EAX;\
>> }\
>> }
>>#endif
>>
>>unsigned __int64 rdtscstart;
>>unsigned __int64 rdtscstop;
>>unsigned __int64 rdtscelapsed=0;
>>
>>StartTimer(rdtscstart);
>>... code goes here...
>>StopTimer(rdtscstop);
>>
>>rdtscelapsed=rdtscstop-rdtscstart;
>>
>>// the 550,000,000 is the clock speed of my processor.
>>
>>double dresult=(double)rdtscelapsed/(double)550000000;
>>char result[64];
>>sprintf(result,"%f",dresult);
>>
>>Larry.
>
>Thanks. I'll try this out.... :)
>
>James
One other note:
My experience with the rdtsc instruction on earlir Pentiums is that it can take
40 to 50 cpu cycles to execute. I have not tested it with my Pentium III xeon
machine.
Larry.
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.