44 lines
975 B
C
44 lines
975 B
C
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/*
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** Cycle count overhead. This is a number of cycles required to actually
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** calculate the cycle count. To get the actual number of net cycles between
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** two calls to GetCycleCount, subtract CCNT_OVERHEAD.
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**
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** For example:
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**
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** __int64 start, finish, actual_cycle_count;
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**
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** start = GetCycleCount ();
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**
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** ... do some stuff ...
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**
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** finish = GetCycleCount ();
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**
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** actual_cycle_count = finish - start - CCNT_OVERHEAD;
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**
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**
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*/
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#define CCNT_OVERHEAD 8
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#pragma warning( disable: 4035 ) /* Don't complain about lack of return value */
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__inline __int64 GetCycleCount ()
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{
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__asm _emit 0x0F
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__asm _emit 0x31 /* rdtsc */
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// return EDX:EAX causes annoying warning
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};
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__inline unsigned GetCycleCount32 () // enough for about 40 seconds
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{
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__asm push EDX
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__asm _emit 0x0F
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__asm _emit 0x31 /* rdtsc */
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__asm pop EDX
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// return EAX causes annoying warning
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};
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#pragma warning( default: 4035 )
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