Index: third_party/tcmalloc/chromium/src/base/cycleclock.h |
=================================================================== |
--- third_party/tcmalloc/chromium/src/base/cycleclock.h (revision 87277) |
+++ third_party/tcmalloc/chromium/src/base/cycleclock.h (working copy) |
@@ -46,33 +46,45 @@ |
#define GOOGLE_BASE_CYCLECLOCK_H_ |
#include "base/basictypes.h" // make sure we get the def for int64 |
+#include "base/arm_instruction_set_select.h" |
#if defined(__MACH__) && defined(__APPLE__) |
-#include <mach/mach_time.h> |
+# include <mach/mach_time.h> |
#endif |
+// For MSVC, we want the __rdtsc intrinsic, declared in <intrin.h>. |
+// Unfortunately, in some environments, <windows.h> and <intrin.h> have |
+// conflicting declarations of some other intrinsics, breaking compilation. |
+// Therefore, we simply declare __rdtsc ourselves. See also |
+// http://connect.microsoft.com/VisualStudio/feedback/details/262047 |
+#if defined(_MSC_VER) |
+extern "C" uint64 __rdtsc(); |
+#pragma intrinsic(__rdtsc) |
+#endif |
+#ifdef HAVE_SYS_TIME_H |
+#include <sys/time.h> |
+#endif |
// NOTE: only i386 and x86_64 have been well tested. |
// PPC, sparc, alpha, and ia64 are based on |
// http://peter.kuscsik.com/wordpress/?p=14 |
-// with modifications by m3b. cf |
+// with modifications by m3b. See also |
// https://setisvn.ssl.berkeley.edu/svn/lib/fftw-3.0.1/kernel/cycle.h |
struct CycleClock { |
// This should return the number of cycles since power-on. Thread-safe. |
static inline int64 Now() { |
#if defined(__MACH__) && defined(__APPLE__) |
- // this goes at the top because we need ALL Macs, regardless |
- // of architecture, to return the number of "mach time units" |
- // that have passes since startup. See sysinfo.cc where |
- // InitializeSystemInfo() sets the supposed cpu clock frequency of macs |
- // to the number of mach time units per second, not actual |
+ // this goes at the top because we need ALL Macs, regardless of |
+ // architecture, to return the number of "mach time units" that |
+ // have passed since startup. See sysinfo.cc where |
+ // InitializeSystemInfo() sets the supposed cpu clock frequency of |
+ // macs to the number of mach time units per second, not actual |
// CPU clock frequency (which can change in the face of CPU |
- // frequency scaling). also note that when the Mac sleeps, |
- // this counter pauses; it does not continue counting, nor resets |
- // to zero. |
+ // frequency scaling). Also note that when the Mac sleeps, this |
+ // counter pauses; it does not continue counting, nor does it |
+ // reset to zero. |
return mach_absolute_time(); |
#elif defined(__i386__) |
int64 ret; |
- __asm__ volatile ("rdtsc" |
- : "=A" (ret) ); |
+ __asm__ volatile ("rdtsc" : "=A" (ret) ); |
return ret; |
#elif defined(__x86_64__) || defined(__amd64__) |
uint64 low, high; |
@@ -82,7 +94,7 @@ |
// This returns a time-base, which is not always precisely a cycle-count. |
int64 tbl, tbu0, tbu1; |
asm("mftbu %0" : "=r" (tbu0)); |
- asm("mftb %0" : "=r" (tbl )); |
+ asm("mftb %0" : "=r" (tbl)); |
asm("mftbu %0" : "=r" (tbu1)); |
tbl &= -static_cast<int64>(tbu0 == tbu1); |
// high 32 bits in tbu1; low 32 bits in tbl (tbu0 is garbage) |
@@ -96,11 +108,31 @@ |
int64 itc; |
asm("mov %0 = ar.itc" : "=r" (itc)); |
return itc; |
-#elif defined(_MSC_VER) && defined(_M_IX86) |
- _asm rdtsc |
+#elif defined(_MSC_VER) |
+ return __rdtsc(); |
+#elif defined(ARMV3) |
+#if defined(ARMV6) // V6 is the earliest arch that has a standard cyclecount |
+ uint32 pmccntr; |
+ uint32 pmuseren; |
+ uint32 pmcntenset; |
+ // Read the user mode perf monitor counter access permissions. |
+ asm("mrc p15, 0, %0, c9, c14, 0" : "=r" (pmuseren)); |
+ if (pmuseren & 1) { // Allows reading perfmon counters for user mode code. |
+ asm("mrc p15, 0, %0, c9, c12, 1" : "=r" (pmcntenset)); |
+ if (pmcntenset & 0x80000000ul) { // Is it counting? |
+ asm("mrc p15, 0, %0, c9, c13, 0" : "=r" (pmccntr)); |
+ // The counter is set up to count every 64th cycle |
+ return static_cast<int64>(pmccntr) * 64; // Should optimize to << 6 |
+ } |
+ } |
+#endif |
+ struct timeval tv; |
+ gettimeofday(&tv, NULL); |
+ return static_cast<int64>(tv.tv_sec) * 1000000 + tv.tv_usec; |
#else |
- // We could define __alpha here as well, but it only has a 32-bit |
- // timer (good for like 4 seconds), which isn't very useful. |
+// The soft failover to a generic implementation is automatic only for ARM. |
+// For other platforms the developer is expected to make an attempt to create |
+// a fast implementation and use generic version if nothing better is available. |
#error You need to define CycleTimer for your O/S and CPU |
#endif |
} |