diff options
Diffstat (limited to 'abseil-cpp/absl/base/internal/unscaledcycleclock.h')
| -rw-r--r-- | abseil-cpp/absl/base/internal/unscaledcycleclock.h | 52 |
1 files changed, 12 insertions, 40 deletions
diff --git a/abseil-cpp/absl/base/internal/unscaledcycleclock.h b/abseil-cpp/absl/base/internal/unscaledcycleclock.h index 82f2c87..cc1276b 100644 --- a/abseil-cpp/absl/base/internal/unscaledcycleclock.h +++ b/abseil-cpp/absl/base/internal/unscaledcycleclock.h @@ -42,49 +42,11 @@ #include <TargetConditionals.h> #endif -#include "absl/base/port.h" - -// The following platforms have an implementation of a hardware counter. -#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \ - defined(__powerpc__) || defined(__ppc__) || \ - defined(_M_IX86) || defined(_M_X64) -#define ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION 1 -#else -#define ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION 0 -#endif - -// The following platforms often disable access to the hardware -// counter (through a sandbox) even if the underlying hardware has a -// usable counter. The CycleTimer interface also requires a *scaled* -// CycleClock that runs at atleast 1 MHz. We've found some Android -// ARM64 devices where this is not the case, so we disable it by -// default on Android ARM64. -#if defined(__native_client__) || \ - (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) || \ - (defined(__ANDROID__) && defined(__aarch64__)) -#define ABSL_USE_UNSCALED_CYCLECLOCK_DEFAULT 0 -#else -#define ABSL_USE_UNSCALED_CYCLECLOCK_DEFAULT 1 -#endif - -// UnscaledCycleClock is an optional internal feature. -// Use "#if ABSL_USE_UNSCALED_CYCLECLOCK" to test for its presence. -// Can be overridden at compile-time via -DABSL_USE_UNSCALED_CYCLECLOCK=0|1 -#if !defined(ABSL_USE_UNSCALED_CYCLECLOCK) -#define ABSL_USE_UNSCALED_CYCLECLOCK \ - (ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION && \ - ABSL_USE_UNSCALED_CYCLECLOCK_DEFAULT) -#endif +#include "absl/base/config.h" +#include "absl/base/internal/unscaledcycleclock_config.h" #if ABSL_USE_UNSCALED_CYCLECLOCK -// This macro can be used to test if UnscaledCycleClock::Frequency() -// is NominalCPUFrequency() on a particular platform. -#if (defined(__i386__) || defined(__x86_64__) || \ - defined(_M_IX86) || defined(_M_X64)) -#define ABSL_INTERNAL_UNSCALED_CYCLECLOCK_FREQUENCY_IS_CPU_FREQUENCY -#endif - namespace absl { ABSL_NAMESPACE_BEGIN namespace time_internal { @@ -115,6 +77,16 @@ class UnscaledCycleClock { friend class base_internal::UnscaledCycleClockWrapperForInitializeFrequency; }; +#if defined(__x86_64__) + +inline int64_t UnscaledCycleClock::Now() { + uint64_t low, high; + __asm__ volatile("rdtsc" : "=a"(low), "=d"(high)); + return static_cast<int64_t>((high << 32) | low); +} + +#endif + } // namespace base_internal ABSL_NAMESPACE_END } // namespace absl |