From dd12dd4c67dd4bc6e7a7d071b925afc38e687f8b Mon Sep 17 00:00:00 2001 From: Morph <39850852+Morph1984@users.noreply.github.com> Date: Sat, 22 Apr 2023 22:55:03 -0400 Subject: [PATCH] x64: Deduplicate RDTSC usage --- src/common/CMakeLists.txt | 2 ++ src/common/x64/cpu_detect.cpp | 3 +++ src/common/x64/cpu_wait.cpp | 20 +----------------- src/common/x64/rdtsc.cpp | 39 +++++++++++++++++++++++++++++++++++ src/common/x64/rdtsc.h | 37 +++++++++++++++++++++++++++++++++ 5 files changed, 82 insertions(+), 19 deletions(-) create mode 100644 src/common/x64/rdtsc.cpp create mode 100644 src/common/x64/rdtsc.h diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt index efc4a9fe93..3adf13a3f4 100644 --- a/src/common/CMakeLists.txt +++ b/src/common/CMakeLists.txt @@ -172,6 +172,8 @@ if(ARCHITECTURE_x86_64) x64/cpu_wait.h x64/native_clock.cpp x64/native_clock.h + x64/rdtsc.cpp + x64/rdtsc.h x64/xbyak_abi.h x64/xbyak_util.h ) diff --git a/src/common/x64/cpu_detect.cpp b/src/common/x64/cpu_detect.cpp index 72ed6e96c9..c998b1197e 100644 --- a/src/common/x64/cpu_detect.cpp +++ b/src/common/x64/cpu_detect.cpp @@ -14,6 +14,7 @@ #include "common/common_types.h" #include "common/logging/log.h" #include "common/x64/cpu_detect.h" +#include "common/x64/rdtsc.h" #ifdef _WIN32 #include @@ -187,6 +188,8 @@ static CPUCaps Detect() { caps.tsc_frequency = static_cast(caps.crystal_frequency) * caps.tsc_crystal_ratio_numerator / caps.tsc_crystal_ratio_denominator; + } else { + caps.tsc_frequency = X64::EstimateRDTSCFrequency(); } } diff --git a/src/common/x64/cpu_wait.cpp b/src/common/x64/cpu_wait.cpp index cfeef6a3d3..c53dd49453 100644 --- a/src/common/x64/cpu_wait.cpp +++ b/src/common/x64/cpu_wait.cpp @@ -9,19 +9,11 @@ #include "common/x64/cpu_detect.h" #include "common/x64/cpu_wait.h" +#include "common/x64/rdtsc.h" namespace Common::X64 { #ifdef _MSC_VER -__forceinline static u64 FencedRDTSC() { - _mm_lfence(); - _ReadWriteBarrier(); - const u64 result = __rdtsc(); - _mm_lfence(); - _ReadWriteBarrier(); - return result; -} - __forceinline static void TPAUSE() { // 100,000 cycles is a reasonable amount of time to wait to save on CPU resources. // For reference: @@ -32,16 +24,6 @@ __forceinline static void TPAUSE() { _tpause(0, FencedRDTSC() + PauseCycles); } #else -static u64 FencedRDTSC() { - u64 eax; - u64 edx; - asm volatile("lfence\n\t" - "rdtsc\n\t" - "lfence\n\t" - : "=a"(eax), "=d"(edx)); - return (edx << 32) | eax; -} - static void TPAUSE() { // 100,000 cycles is a reasonable amount of time to wait to save on CPU resources. // For reference: diff --git a/src/common/x64/rdtsc.cpp b/src/common/x64/rdtsc.cpp new file mode 100644 index 0000000000..9273274a39 --- /dev/null +++ b/src/common/x64/rdtsc.cpp @@ -0,0 +1,39 @@ +// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project +// SPDX-License-Identifier: GPL-2.0-or-later + +#include + +#include "common/steady_clock.h" +#include "common/uint128.h" +#include "common/x64/rdtsc.h" + +namespace Common::X64 { + +template +static u64 RoundToNearest(u64 value) { + const auto mod = value % Nearest; + return mod >= (Nearest / 2) ? (value - mod + Nearest) : (value - mod); +} + +u64 EstimateRDTSCFrequency() { + // Discard the first result measuring the rdtsc. + FencedRDTSC(); + std::this_thread::sleep_for(std::chrono::milliseconds{1}); + FencedRDTSC(); + + // Get the current time. + const auto start_time = RealTimeClock::Now(); + const u64 tsc_start = FencedRDTSC(); + // Wait for 100 milliseconds. + std::this_thread::sleep_for(std::chrono::milliseconds{100}); + const auto end_time = RealTimeClock::Now(); + const u64 tsc_end = FencedRDTSC(); + // Calculate differences. + const u64 timer_diff = static_cast( + std::chrono::duration_cast(end_time - start_time).count()); + const u64 tsc_diff = tsc_end - tsc_start; + const u64 tsc_freq = MultiplyAndDivide64(tsc_diff, 1000000000ULL, timer_diff); + return RoundToNearest<100'000>(tsc_freq); +} + +} // namespace Common::X64 diff --git a/src/common/x64/rdtsc.h b/src/common/x64/rdtsc.h new file mode 100644 index 0000000000..0ec4f52f9d --- /dev/null +++ b/src/common/x64/rdtsc.h @@ -0,0 +1,37 @@ +// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project +// SPDX-License-Identifier: GPL-2.0-or-later + +#pragma once + +#ifdef _MSC_VER +#include +#endif + +#include "common/common_types.h" + +namespace Common::X64 { + +#ifdef _MSC_VER +__forceinline static u64 FencedRDTSC() { + _mm_lfence(); + _ReadWriteBarrier(); + const u64 result = __rdtsc(); + _mm_lfence(); + _ReadWriteBarrier(); + return result; +} +#else +static inline u64 FencedRDTSC() { + u64 eax; + u64 edx; + asm volatile("lfence\n\t" + "rdtsc\n\t" + "lfence\n\t" + : "=a"(eax), "=d"(edx)); + return (edx << 32) | eax; +} +#endif + +u64 EstimateRDTSCFrequency(); + +} // namespace Common::X64