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Diffstat (limited to 'src/common/x64/native_clock.cpp')
-rw-r--r--src/common/x64/native_clock.cpp49
1 files changed, 35 insertions, 14 deletions
diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp
index 7a3f21dcf..7fd9d22f8 100644
--- a/src/common/x64/native_clock.cpp
+++ b/src/common/x64/native_clock.cpp
@@ -10,25 +10,49 @@
10#include "common/uint128.h" 10#include "common/uint128.h"
11#include "common/x64/native_clock.h" 11#include "common/x64/native_clock.h"
12 12
13#ifdef _MSC_VER
14#include <intrin.h>
15#endif
16
13namespace Common { 17namespace Common {
14 18
19#ifdef _MSC_VER
20__forceinline static u64 FencedRDTSC() {
21 _mm_lfence();
22 _ReadWriteBarrier();
23 const u64 result = __rdtsc();
24 _mm_lfence();
25 _ReadWriteBarrier();
26 return result;
27}
28#else
29static u64 FencedRDTSC() {
30 u64 result;
31 asm volatile("lfence\n\t"
32 "rdtsc\n\t"
33 "shl $32, %%rdx\n\t"
34 "or %%rdx, %0\n\t"
35 "lfence"
36 : "=a"(result)
37 :
38 : "rdx", "memory", "cc");
39 return result;
40}
41#endif
42
15u64 EstimateRDTSCFrequency() { 43u64 EstimateRDTSCFrequency() {
16 // Discard the first result measuring the rdtsc. 44 // Discard the first result measuring the rdtsc.
17 _mm_mfence(); 45 FencedRDTSC();
18 __rdtsc();
19 std::this_thread::sleep_for(std::chrono::milliseconds{1}); 46 std::this_thread::sleep_for(std::chrono::milliseconds{1});
20 _mm_mfence(); 47 FencedRDTSC();
21 __rdtsc();
22 48
23 // Get the current time. 49 // Get the current time.
24 const auto start_time = std::chrono::steady_clock::now(); 50 const auto start_time = std::chrono::steady_clock::now();
25 _mm_mfence(); 51 const u64 tsc_start = FencedRDTSC();
26 const u64 tsc_start = __rdtsc();
27 // Wait for 200 milliseconds. 52 // Wait for 200 milliseconds.
28 std::this_thread::sleep_for(std::chrono::milliseconds{200}); 53 std::this_thread::sleep_for(std::chrono::milliseconds{200});
29 const auto end_time = std::chrono::steady_clock::now(); 54 const auto end_time = std::chrono::steady_clock::now();
30 _mm_mfence(); 55 const u64 tsc_end = FencedRDTSC();
31 const u64 tsc_end = __rdtsc();
32 // Calculate differences. 56 // Calculate differences.
33 const u64 timer_diff = static_cast<u64>( 57 const u64 timer_diff = static_cast<u64>(
34 std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time).count()); 58 std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time).count());
@@ -42,8 +66,7 @@ NativeClock::NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequen
42 u64 rtsc_frequency_) 66 u64 rtsc_frequency_)
43 : WallClock(emulated_cpu_frequency_, emulated_clock_frequency_, true), rtsc_frequency{ 67 : WallClock(emulated_cpu_frequency_, emulated_clock_frequency_, true), rtsc_frequency{
44 rtsc_frequency_} { 68 rtsc_frequency_} {
45 _mm_mfence(); 69 time_point.inner.last_measure = FencedRDTSC();
46 time_point.inner.last_measure = __rdtsc();
47 time_point.inner.accumulated_ticks = 0U; 70 time_point.inner.accumulated_ticks = 0U;
48 ns_rtsc_factor = GetFixedPoint64Factor(NS_RATIO, rtsc_frequency); 71 ns_rtsc_factor = GetFixedPoint64Factor(NS_RATIO, rtsc_frequency);
49 us_rtsc_factor = GetFixedPoint64Factor(US_RATIO, rtsc_frequency); 72 us_rtsc_factor = GetFixedPoint64Factor(US_RATIO, rtsc_frequency);
@@ -58,8 +81,7 @@ u64 NativeClock::GetRTSC() {
58 81
59 current_time_point.pack = Common::AtomicLoad128(time_point.pack.data()); 82 current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
60 do { 83 do {
61 _mm_mfence(); 84 const u64 current_measure = FencedRDTSC();
62 const u64 current_measure = __rdtsc();
63 u64 diff = current_measure - current_time_point.inner.last_measure; 85 u64 diff = current_measure - current_time_point.inner.last_measure;
64 diff = diff & ~static_cast<u64>(static_cast<s64>(diff) >> 63); // max(diff, 0) 86 diff = diff & ~static_cast<u64>(static_cast<s64>(diff) >> 63); // max(diff, 0)
65 new_time_point.inner.last_measure = current_measure > current_time_point.inner.last_measure 87 new_time_point.inner.last_measure = current_measure > current_time_point.inner.last_measure
@@ -80,8 +102,7 @@ void NativeClock::Pause(bool is_paused) {
80 current_time_point.pack = Common::AtomicLoad128(time_point.pack.data()); 102 current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
81 do { 103 do {
82 new_time_point.pack = current_time_point.pack; 104 new_time_point.pack = current_time_point.pack;
83 _mm_mfence(); 105 new_time_point.inner.last_measure = FencedRDTSC();
84 new_time_point.inner.last_measure = __rdtsc();
85 } while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack, 106 } while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack,
86 current_time_point.pack, current_time_point.pack)); 107 current_time_point.pack, current_time_point.pack));
87 } 108 }