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/* $Id$ */
#include "stdafx.h"
#undef RDTSC_AVAILABLE
/* rdtsc for MSC_VER, uses simple inline assembly, or _rdtsc
* from external win64.asm because VS2005 does not support inline assembly */
#if defined(_MSC_VER) && !defined(RDTSC_AVAILABLE)
# if defined (_M_AMD64)
extern uint64 _rdtsc(void);
# else
uint64 _declspec(naked) _rdtsc(void)
{
_asm {
rdtsc
ret
}
}
# endif
# define RDTSC_AVAILABLE
#endif
/* rdtsc for OS/2. Hopefully this works, who knows */
#if defined (__WATCOMC__) && !defined(RDTSC_AVAILABLE)
unsigned __int64 _rdtsc( void);
# pragma aux _rdtsc = 0x0F 0x31 value [edx eax] parm nomemory modify exact [edx eax] nomemory;
# define RDTSC_AVAILABLE
#endif
/* rdtsc for all other *nix-en (hopefully). Use GCC syntax */
#if defined(__i386__) || defined(__x86_64__) && !defined(RDTSC_AVAILABLE)
uint64 _rdtsc(void)
{
uint32 high, low;
__asm__ __volatile__ ("rdtsc" : "=a" (low), "=d" (high));
return ((uint64)high << 32) | low;
}
# define RDTSC_AVAILABLE
#endif
/* rdtsc for PPC which has this not */
#if defined(__POWERPC__) && !defined(RDTSC_AVAILABLE)
uint64 _rdtsc(void)
{
uint32 high = 0, high2 = 0, low;
/* PPC does not have rdtsc, so we cheat by reading the two 32-bit time-counters
* it has, 'Move From Time Base (Upper)'. Since these are two reads, in the
* very unlikely event that the lower part overflows to the upper part while we
* read it; we double-check and reread the registers */
asm volatile (
"mftbu %0\n"
"mftb %1\n"
"mftbu %2\n"
"cmpw %3,%4\n"
"bne- $-16\n"
: "=r" (high), "=r" (low), "=r" (high2)
: "0" (high), "2" (high2)
);
return ((uint64)high << 32) | low;
}
# define RDTSC_AVAILABLE
#endif
/* In all other cases we have no support for rdtsc. No major issue,
* you just won't be able to profile your code with TIC()/TOC() */
#if !defined(RDTSC_AVAILABLE)
#warning "OS has no support for rdtsc()"
uint64 _rdtsc(void) {return 0;}
#endif
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