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-rw-r--r--src/common/wall_clock.cpp16
-rw-r--r--src/common/wall_clock.h8
-rw-r--r--src/common/x64/native_clock.cpp6
3 files changed, 19 insertions, 11 deletions
diff --git a/src/common/wall_clock.cpp b/src/common/wall_clock.cpp
index ffa282e88..9acf7551e 100644
--- a/src/common/wall_clock.cpp
+++ b/src/common/wall_clock.cpp
@@ -65,16 +65,20 @@ private:
#ifdef ARCHITECTURE_x86_64
-std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
- u32 emulated_clock_frequency) {
+std::unique_ptr<WallClock> CreateBestMatchingClock(u64 emulated_cpu_frequency,
+ u64 emulated_clock_frequency) {
const auto& caps = GetCPUCaps();
u64 rtsc_frequency = 0;
if (caps.invariant_tsc) {
rtsc_frequency = EstimateRDTSCFrequency();
}
- // Fallback to StandardWallClock if rtsc period is higher than a nano second
- if (rtsc_frequency <= 1000000000) {
+ // Fallback to StandardWallClock if the hardware TSC does not have the precision greater than:
+ // - A nanosecond
+ // - The emulated CPU frequency
+ // - The emulated clock counter frequency (CNTFRQ)
+ if (rtsc_frequency <= WallClock::NS_RATIO || rtsc_frequency <= emulated_cpu_frequency ||
+ rtsc_frequency <= emulated_clock_frequency) {
return std::make_unique<StandardWallClock>(emulated_cpu_frequency,
emulated_clock_frequency);
} else {
@@ -85,8 +89,8 @@ std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
#else
-std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
- u32 emulated_clock_frequency) {
+std::unique_ptr<WallClock> CreateBestMatchingClock(u64 emulated_cpu_frequency,
+ u64 emulated_clock_frequency) {
return std::make_unique<StandardWallClock>(emulated_cpu_frequency, emulated_clock_frequency);
}
diff --git a/src/common/wall_clock.h b/src/common/wall_clock.h
index cef3e9499..874448c27 100644
--- a/src/common/wall_clock.h
+++ b/src/common/wall_clock.h
@@ -13,6 +13,10 @@ namespace Common {
class WallClock {
public:
+ static constexpr u64 NS_RATIO = 1'000'000'000;
+ static constexpr u64 US_RATIO = 1'000'000;
+ static constexpr u64 MS_RATIO = 1'000;
+
virtual ~WallClock() = default;
/// Returns current wall time in nanoseconds
@@ -49,7 +53,7 @@ private:
bool is_native;
};
-[[nodiscard]] std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
- u32 emulated_clock_frequency);
+[[nodiscard]] std::unique_ptr<WallClock> CreateBestMatchingClock(u64 emulated_cpu_frequency,
+ u64 emulated_clock_frequency);
} // namespace Common
diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp
index 82ee2c8a1..91b842829 100644
--- a/src/common/x64/native_clock.cpp
+++ b/src/common/x64/native_clock.cpp
@@ -47,9 +47,9 @@ NativeClock::NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequen
_mm_mfence();
time_point.inner.last_measure = __rdtsc();
time_point.inner.accumulated_ticks = 0U;
- ns_rtsc_factor = GetFixedPoint64Factor(1000000000, rtsc_frequency);
- us_rtsc_factor = GetFixedPoint64Factor(1000000, rtsc_frequency);
- ms_rtsc_factor = GetFixedPoint64Factor(1000, rtsc_frequency);
+ ns_rtsc_factor = GetFixedPoint64Factor(NS_RATIO, rtsc_frequency);
+ us_rtsc_factor = GetFixedPoint64Factor(US_RATIO, rtsc_frequency);
+ ms_rtsc_factor = GetFixedPoint64Factor(MS_RATIO, rtsc_frequency);
clock_rtsc_factor = GetFixedPoint64Factor(emulated_clock_frequency, rtsc_frequency);
cpu_rtsc_factor = GetFixedPoint64Factor(emulated_cpu_frequency, rtsc_frequency);
}