danicoin/external/glim/TscTimer.hpp
Thomas Winget 90d6f8bf62 Adding libglim as an external library
libglim is an Apache-licensed C++ wrapper for lmdb, and rather than
rolling our own it seems prudent to use it.

Note: lmdb is not included in it, and unless something happens as did
with libunbound, should be installed via each OS' package manager or
equivalent.
2015-01-04 18:41:44 -08:00

32 lines
837 B
C++

#ifndef _TSC_TIMER_H
#define _TSC_TIMER_H
namespace glim {
extern "C" { // http://en.wikipedia.org/wiki/Rdtsc
#if (defined(__GNUC__) || defined(__ICC)) && defined(__i386__)
static __inline__ unsigned long long rdTsc(void) {
unsigned long long ret;
__asm__ __volatile__("rdtsc": "=A" (ret));
return ret;
}
#elif (defined(__GNUC__) || defined(__ICC) || defined(__SUNPRO_C)) && defined(__x86_64__)
static __inline__ unsigned long long rdTsc(void) {
unsigned a, d;
asm volatile("rdtsc" : "=a" (a), "=d" (d));
return ((unsigned long long)a) | (((unsigned long long)d) << 32);
}
#endif
}
//! CPU cycles timer. Fast, not safe.
//! cf. http://en.wikipedia.org/wiki/Rdtsc
struct TscTimer {
int64_t start;
TscTimer (): start (rdTsc()) {}
int64_t operator()() const {return rdTsc() - start;}
};
}
#endif // _TSC_TIMER_H