Intermediate changes

2 files changed, 17 insertions, 2 deletions

diff --git a/library/cpp/yt/cpu_clock/clock-inl.h b/library/cpp/yt/cpu_clock/clock-inl.h
index a69163a428..6402279294 100644
--- a/library/cpp/yt/cpu_clock/clock-inl.h
+++ b/library/cpp/yt/cpu_clock/clock-inl.h
@@ -11,11 +11,23 @@ namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-inline TCpuInstant GetCpuInstant()
+Y_FORCE_INLINE TCpuInstant GetCpuInstant()
 {
     return static_cast<TCpuInstant>(GetCycleCount());
 }
 
+Y_FORCE_INLINE TCpuInstant GetApproximateCpuInstant()
+{
+#if defined(_x86_64_)
+    ui32 hi, lo;
+    __asm__ __volatile__("rdtsc"
+                        : "=a"(lo), "=d"(hi));
+    return static_cast<TCpuInstant>(lo) | (static_cast<TCpuInstant>(hi) << 32);
+#else
+    return GetCpuInstant();
+#endif
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT
diff --git a/library/cpp/yt/cpu_clock/clock.h b/library/cpp/yt/cpu_clock/clock.h
index 96f22c3833..9729d1e8eb 100644
--- a/library/cpp/yt/cpu_clock/clock.h
+++ b/library/cpp/yt/cpu_clock/clock.h
@@ -8,9 +8,12 @@ namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-//! Returns the current processor clock (rdtsc).
+//! Returns the current processor clock (typically obtained via |rdtscp| instruction).
 TCpuInstant GetCpuInstant();
 
+//! Returns the approximate current processor clock (obtained via |rdtsc| instruction).
+TCpuInstant GetApproximateCpuInstant();
+
 //! Returns the current time (obtained via #GetCpuInstant).
 TInstant GetInstant();