common: Rework timekeeping with native RDTSC and port to linux

src/common/native_clock.cpp

@@ -0,0 +1,43 @@
+// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "common/uint128.h"
+#include "common/native_clock.h"
+#include "common/rdtsc.h"
+#ifdef _WIN64
+#include <pthread_time.h>
+#else
+#include <time.h>
+#endif
+
+namespace Common {
+
+NativeClock::NativeClock()
+    : rdtsc_frequency{EstimateRDTSCFrequency()}, ns_rdtsc_factor{GetFixedPoint64Factor(std::nano::den,
+                                                                               rdtsc_frequency)},
+      us_rdtsc_factor{GetFixedPoint64Factor(std::micro::den, rdtsc_frequency)},
+      ms_rdtsc_factor{GetFixedPoint64Factor(std::milli::den, rdtsc_frequency)} {}
+
+u64 NativeClock::GetTimeNS() const {
+    return MultiplyHigh(GetUptime(), ns_rdtsc_factor);
+}
+
+u64 NativeClock::GetTimeUS() const {
+    return MultiplyHigh(GetUptime(), us_rdtsc_factor);
+}
+
+u64 NativeClock::GetTimeMS() const {
+    return MultiplyHigh(GetUptime(), ms_rdtsc_factor);
+}
+
+u64 NativeClock::GetUptime() const {
+    return FencedRDTSC();
+}
+
+u64 NativeClock::GetProcessTimeUS() const {
+    timespec ret;
+    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ret);
+    return ret.tv_nsec / 1000 + ret.tv_sec * 1000000;
+}
+
+} // namespace Common::X64