The IA32 variant of InternalSyncCompareExchange64() is correct, but we can simplify it. We don't need to load the lower 32 bits of ExchangeValue into EBX in two steps (first into a general register, then into EBX); we can ask GCC to populate EBX like that itself.
Cc: Liming Gao <[email protected]> Cc: Michael D Kinney <[email protected]> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1208 Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <[email protected]> --- MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c b/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c index 44188e265af2..af39bdeb516c 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c +++ b/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c @@ -193,14 +193,11 @@ InternalSyncCompareExchange64 ( ) { __asm__ __volatile__ ( - "push %%ebx \n\t" - "movl %2,%%ebx \n\t" "lock \n\t" "cmpxchg8b (%1) \n\t" - "pop %%ebx \n\t" : "+A" (CompareValue) // %0 : "S" (Value), // %1 - "r" ((UINT32) ExchangeValue), // %2 + "b" ((UINT32) ExchangeValue), // %2 "c" ((UINT32) (ExchangeValue >> 32)) // %3 : "memory", "cc" -- 2.14.1.3.gb7cf6e02401b _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
