From 58168a8c3c70527c9ed12e4e861a634fac05d55d Mon Sep 17 00:00:00 2001 From: "Ryan C. Gordon" Date: Mon, 25 Jun 2018 16:34:16 -0400 Subject: [PATCH] atomic: Fight with all the assemblers that don't like REP NOP. :/ --- src/atomic/SDL_spinlock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/src/atomic/SDL_spinlock.c b/src/atomic/SDL_spinlock.c index f5e17d0a6b058..8630e668ec295 100644 --- a/src/atomic/SDL_spinlock.c +++ b/src/atomic/SDL_spinlock.c @@ -122,12 +122,13 @@ SDL_AtomicTryLock(SDL_SpinLock *lock) /* "REP NOP" is PAUSE, coded for tools that don't know it by that name. */ #if (defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__)) - #define PAUSE_INSTRUCTION() __asm__ __volatile__("rep nop\n") + #define PAUSE_INSTRUCTION() __asm__ __volatile__("pause\n") /* Clang lets you do REP NOP, GCC wants PAUSE. */ #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64)) - #define PAUSE_INSRUCTION() _mm_pause() /* this is actually "rep nop" and not a SIMD instruction. */ + #define PAUSE_INSRUCTION() _mm_pause() /* this is actually "rep nop" and not a SIMD instruction. No inline asm in MSVC x86-64! */ #elif defined(__WATCOMC__) && defined(__386__) + /* watcom assembler won't let you do PAUSE, but refuses REP NOP as an invalid combination. Hardcode the bytes. */ extern _inline void PAUSE_INSTRUCTION(void); - #pragma aux PAUSE_INSTRUCTION = "rep nop" + #pragma aux PAUSE_INSTRUCTION = "db 0f3h,90h" #else #define PAUSE_INSTRUCTION() #endif