nanobench on Windows: try compiler barriers around timer instead.
BUG=skia:
Review URL: https://codereview.chromium.org/391193003
diff --git a/gyp/bench.gyp b/gyp/bench.gyp
index 86fb1df..6618403 100644
--- a/gyp/bench.gyp
+++ b/gyp/bench.gyp
@@ -48,9 +48,6 @@
'tools.gyp:crash_handler',
'tools.gyp:timer',
],
-
- # Experiment to see if LTCG is the key difference leading to Windows infinite loops.
- 'msvs_settings': { 'VCLinkerTool': { 'LinkTimeCodeGeneration': '0' } },
},
],
}
diff --git a/tools/timer/SysTimer_windows.cpp b/tools/timer/SysTimer_windows.cpp
index 2f9d0a5..d24a6aa 100644
--- a/tools/timer/SysTimer_windows.cpp
+++ b/tools/timer/SysTimer_windows.cpp
@@ -6,6 +6,8 @@
*/
#include "SysTimer_windows.h"
+#include <intrin.h>
+
static ULONGLONG win_cpu_time() {
FILETIME createTime;
FILETIME exitTime;
@@ -23,11 +25,6 @@
return start_cpu_sys.QuadPart + start_cpu_usr.QuadPart;
}
-void SysTimer::startWall() {
- if (0 == ::QueryPerformanceCounter(&fStartWall)) {
- fStartWall.QuadPart = 0;
- }
-}
void SysTimer::startCpu() {
fStartCpu = win_cpu_time();
}
@@ -36,11 +33,22 @@
ULONGLONG end_cpu = win_cpu_time();
return static_cast<double>(end_cpu - fStartCpu) / 10000.0L;
}
+
+static void wall_timestamp(LARGE_INTEGER* now) {
+ _ReadWriteBarrier();
+ if (0 == ::QueryPerformanceCounter(now)) {
+ now->QuadPart = 0;
+ }
+ _ReadWriteBarrier();
+}
+
+void SysTimer::startWall() {
+ wall_timestamp(&fStartWall);
+}
+
double SysTimer::endWall() {
LARGE_INTEGER end_wall;
- if (0 == ::QueryPerformanceCounter(&end_wall)) {
- end_wall.QuadPart = 0;
- }
+ wall_timestamp(&end_wall);
LARGE_INTEGER ticks_elapsed;
ticks_elapsed.QuadPart = end_wall.QuadPart - fStartWall.QuadPart;