From 981bc8aa1c924eabc55f63f9671324c548c72d59 Mon Sep 17 00:00:00 2001 From: Morph <39850852+Morph1984@users.noreply.github.com> Date: Wed, 22 Mar 2023 16:40:41 -0400 Subject: [PATCH] x64: Simplify RDTSC on non-MSVC compilers Co-Authored-By: liamwhite --- src/common/x64/cpu_wait.cpp | 13 +++++-------- src/common/x64/native_clock.cpp | 13 +++++-------- 2 files changed, 10 insertions(+), 16 deletions(-) diff --git a/src/common/x64/cpu_wait.cpp b/src/common/x64/cpu_wait.cpp index 1fab0bfe8..cfeef6a3d 100644 --- a/src/common/x64/cpu_wait.cpp +++ b/src/common/x64/cpu_wait.cpp @@ -33,16 +33,13 @@ __forceinline static void TPAUSE() { } #else static u64 FencedRDTSC() { - u64 result; + u64 eax; + u64 edx; asm volatile("lfence\n\t" "rdtsc\n\t" - "shl $32, %%rdx\n\t" - "or %%rdx, %0\n\t" - "lfence" - : "=a"(result) - : - : "rdx", "memory", "cc"); - return result; + "lfence\n\t" + : "=a"(eax), "=d"(edx)); + return (edx << 32) | eax; } static void TPAUSE() { diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp index 76c66e7ee..277b00662 100644 --- a/src/common/x64/native_clock.cpp +++ b/src/common/x64/native_clock.cpp @@ -27,16 +27,13 @@ __forceinline static u64 FencedRDTSC() { } #else static u64 FencedRDTSC() { - u64 result; + u64 eax; + u64 edx; asm volatile("lfence\n\t" "rdtsc\n\t" - "shl $32, %%rdx\n\t" - "or %%rdx, %0\n\t" - "lfence" - : "=a"(result) - : - : "rdx", "memory", "cc"); - return result; + "lfence\n\t" + : "=a"(eax), "=d"(edx)); + return (edx << 32) | eax; } #endif