XForYouX/suyu
1
0
Fork 0
forked from suyu/suyu
Code Pull requests Releases Activity

native_clock: Use writeback from CAS to avoid double-loading

Browse source
This commit is contained in:
merry 2022-04-02 21:05:49 +01:00
parent 084bd225dc
commit 979e53b87b
1 changed files with 6 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
src/common/x64/native_clock.cpp
View file

@ -55,8 +55,9 @@ NativeClock::NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequen
u64 NativeClock::GetRTSC() { u64 NativeClock::GetRTSC() {
TimePoint new_time_point{}; TimePoint new_time_point{};
TimePoint current_time_point{}; TimePoint current_time_point{};
current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
do { do {
current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
_mm_mfence(); _mm_mfence();
const u64 current_measure = __rdtsc(); const u64 current_measure = __rdtsc();
u64 diff = current_measure - current_time_point.inner.last_measure; u64 diff = current_measure - current_time_point.inner.last_measure;
@ -66,7 +67,7 @@ u64 NativeClock::GetRTSC() {
: current_time_point.inner.last_measure; : current_time_point.inner.last_measure;
new_time_point.inner.accumulated_ticks = current_time_point.inner.accumulated_ticks + diff; new_time_point.inner.accumulated_ticks = current_time_point.inner.accumulated_ticks + diff;
} while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack, } while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack,
current_time_point.pack)); current_time_point.pack, current_time_point.pack));
/// The clock cannot be more precise than the guest timer, remove the lower bits /// The clock cannot be more precise than the guest timer, remove the lower bits
return new_time_point.inner.accumulated_ticks & inaccuracy_mask; return new_time_point.inner.accumulated_ticks & inaccuracy_mask;
} }
@ -75,13 +76,14 @@ void NativeClock::Pause(bool is_paused) {
if (!is_paused) { if (!is_paused) {
TimePoint current_time_point{}; TimePoint current_time_point{};
TimePoint new_time_point{}; TimePoint new_time_point{};
current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
do { do {
current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
new_time_point.pack = current_time_point.pack; new_time_point.pack = current_time_point.pack;
_mm_mfence(); _mm_mfence();
new_time_point.inner.last_measure = __rdtsc(); new_time_point.inner.last_measure = __rdtsc();
} while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack, } while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack,
current_time_point.pack)); current_time_point.pack, current_time_point.pack));
} }
} }