diff options
Diffstat (limited to 'third_party/tcmalloc/chromium/src/base/cycleclock.h')
| -rw-r--r-- | third_party/tcmalloc/chromium/src/base/cycleclock.h | 66 |
1 files changed, 49 insertions, 17 deletions
diff --git a/third_party/tcmalloc/chromium/src/base/cycleclock.h b/third_party/tcmalloc/chromium/src/base/cycleclock.h index 8af664ed..6d6822a 100644 --- a/third_party/tcmalloc/chromium/src/base/cycleclock.h +++ b/third_party/tcmalloc/chromium/src/base/cycleclock.h @@ -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 @@ struct CycleClock { // 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 @@ struct CycleClock { 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 } |