From 295fc7d0f8f0b6158307c5c9b11a60516f9eb221 Mon Sep 17 00:00:00 2001 From: Morph <39850852+Morph1984@users.noreply.github.com> Date: Wed, 28 Jun 2023 01:35:16 -0400 Subject: [PATCH] x64: cpu_wait: Implement MWAITX for non-MSVC compilers --- src/common/x64/cpu_wait.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/common/x64/cpu_wait.cpp b/src/common/x64/cpu_wait.cpp index ea16c8490..41d385f59 100644 --- a/src/common/x64/cpu_wait.cpp +++ b/src/common/x64/cpu_wait.cpp @@ -47,6 +47,16 @@ static void TPAUSE() { const auto edx = static_cast(tsc >> 32); asm volatile("tpause %0" : : "r"(RequestC02State), "d"(edx), "a"(eax)); } + +static void MWAITX() { + static constexpr auto EnableWaitTimeFlag = 1U << 1; + static constexpr auto RequestC1State = 0U; + + // monitor_var should be aligned to a cache line. + alignas(64) u64 monitor_var{}; + asm volatile("monitorx" : : "a"(&monitor_var), "c"(0), "d"(0)); + asm volatile("mwaitx" : : "a"(RequestC1State), "b"(PauseCycles), "c"(EnableWaitTimeFlag)); +} #endif void MicroSleep() {