1 files changed, 10 insertions, 0 deletions
diff --git a/absl/base/internal/unscaledcycleclock.h b/absl/base/internal/unscaledcycleclock.h
index 681ff8f9..07f867a6 100644
--- a/absl/base/internal/unscaledcycleclock.h
+++ b/absl/base/internal/unscaledcycleclock.h
@@ -115,6 +115,16 @@ 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 (high << 32) | low;
+}
+
+#endif
+
 }  // namespace base_internal
 ABSL_NAMESPACE_END
 }  // namespace absl