| //------------------------------------------------------------------------------------------------------------------------------ |
| // Samuel Williams |
| // SWWilliams@lbl.gov |
| // Lawrence Berkeley National Lab |
| //------------------------------------------------------------------------------------------------------------------------------ |
| #include <stdint.h> |
| uint64_t CycleTime(){ |
| #ifndef __has_builtin |
| #define __has_builtin(x) 0 |
| #endif |
| |
| #if !defined(USE_CYCLE_COUNTER) |
| return 0; |
| #elif __has_builtin(__builtin_readcyclecounter) |
| return __builtin_readcyclecounter(); |
| #else |
| uint64_t lo, hi; |
| __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi)); |
| return( (((uint64_t)hi) << 32) | ((uint64_t)lo) ); |
| #endif |
| } |
