diff options
Diffstat (limited to 'sysdeps/x86')
| -rw-r--r-- | sysdeps/x86/hp-timing.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/sysdeps/x86/hp-timing.h b/sysdeps/x86/hp-timing.h index 77a1360748..0aa6f5e3f8 100644 --- a/sysdeps/x86/hp-timing.h +++ b/sysdeps/x86/hp-timing.h @@ -40,7 +40,19 @@ typedef unsigned long long int hp_timing_t; NB: Use __builtin_ia32_rdtsc directly since including <x86intrin.h> makes building glibc very slow. */ -# define HP_TIMING_NOW(Var) ((Var) = __builtin_ia32_rdtsc ()) +# ifdef USE_RDTSCP +/* RDTSCP waits until all previous instructions have executed and all + previous loads are globally visible before reading the counter. + RDTSC doesn't wait until all previous instructions have been executed + before reading the counter. */ +# define HP_TIMING_NOW(Var) \ + (__extension__ ({ \ + unsigned int __aux; \ + (Var) = __builtin_ia32_rdtscp (&__aux); \ + })) +# else +# define HP_TIMING_NOW(Var) ((Var) = __builtin_ia32_rdtsc ()) +# endif # include <hp-timing-common.h> #else |