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| author | Jonathan Peyton <jonathan.l.peyton@intel.com> | 2017-03-20 22:11:31 +0000 |
|---|---|---|
| committer | Jonathan Peyton <jonathan.l.peyton@intel.com> | 2017-03-20 22:11:31 +0000 |
| commit | 35d75aeda29ede36e187d8b6f6fca0e1ed7569a8 (patch) | |
| tree | 5d84edf42f3f39eb116aa628a371e28c03ea0d29 /openmp/runtime/src | |
| parent | 16fd8fec76129351e053ed5bf64a0f972b48dcb3 (diff) | |
| download | bcm5719-llvm-35d75aeda29ede36e187d8b6f6fca0e1ed7569a8.tar.gz bcm5719-llvm-35d75aeda29ede36e187d8b6f6fca0e1ed7569a8.zip | |
Minor improvement of KMP_YIELD_NOW() macro.
This change slightly improves performance of KMP_YIELD_NOW() macro, by using
_rdtsc() intrinsic function if possible.
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D31008
llvm-svn: 298314
Diffstat (limited to 'openmp/runtime/src')
| -rw-r--r-- | openmp/runtime/src/kmp.h | 12 | ||||
| -rw-r--r-- | openmp/runtime/src/z_Linux_util.cpp | 6 |
2 files changed, 11 insertions, 7 deletions
diff --git a/openmp/runtime/src/kmp.h b/openmp/runtime/src/kmp.h index 885495218ea..c89506e9254 100644 --- a/openmp/runtime/src/kmp.h +++ b/openmp/runtime/src/kmp.h @@ -894,10 +894,14 @@ extern int __kmp_place_num_threads_per_core; #else # if KMP_OS_UNIX && (KMP_ARCH_X86 || KMP_ARCH_X86_64) // HW TSC is used to reduce overhead (clock tick instead of nanosecond). - extern double __kmp_ticks_per_nsec; -# define KMP_NOW() __kmp_hardware_timestamp() -# define KMP_NOW_MSEC() ((kmp_uint64)(KMP_NOW()/__kmp_ticks_per_nsec)/KMP_USEC_PER_SEC) -# define KMP_BLOCKTIME_INTERVAL() (__kmp_dflt_blocktime * KMP_USEC_PER_SEC * __kmp_ticks_per_nsec) + extern kmp_uint64 __kmp_ticks_per_msec; +# if KMP_COMPILER_ICC +# define KMP_NOW() _rdtsc() +# else +# define KMP_NOW() __kmp_hardware_timestamp() +# endif +# define KMP_NOW_MSEC() (KMP_NOW()/__kmp_ticks_per_msec) +# define KMP_BLOCKTIME_INTERVAL() (__kmp_dflt_blocktime * __kmp_ticks_per_msec) # define KMP_BLOCKING(goal, count) ((goal) > KMP_NOW()) # else // System time is retrieved sporadically while blocking. diff --git a/openmp/runtime/src/z_Linux_util.cpp b/openmp/runtime/src/z_Linux_util.cpp index 34114bcbb02..2c034f9c560 100644 --- a/openmp/runtime/src/z_Linux_util.cpp +++ b/openmp/runtime/src/z_Linux_util.cpp @@ -90,7 +90,7 @@ static pthread_mutexattr_t __kmp_suspend_mutex_attr; static kmp_cond_align_t __kmp_wait_cv; static kmp_mutex_align_t __kmp_wait_mx; -double __kmp_ticks_per_nsec; +kmp_uint64 __kmp_ticks_per_msec = 1000000; /* ------------------------------------------------------------------------ */ /* ------------------------------------------------------------------------ */ @@ -2157,7 +2157,7 @@ __kmp_now_nsec() } #if KMP_ARCH_X86 || KMP_ARCH_X86_64 -/* Measure clock tick per nanosecond */ +/* Measure clock ticks per millisecond */ void __kmp_initialize_system_tick() { @@ -2166,7 +2166,7 @@ __kmp_initialize_system_tick() kmp_uint64 goal = __kmp_hardware_timestamp() + delay; kmp_uint64 now; while ((now = __kmp_hardware_timestamp()) < goal); - __kmp_ticks_per_nsec = 1.0 * (delay + (now - goal)) / (__kmp_now_nsec() - nsec); + __kmp_ticks_per_msec = (kmp_uint64)(1e6 * (delay + (now - goal)) / (__kmp_now_nsec() - nsec)); } #endif |
