On 10/01/18 20:27, Philippe Mathieu-Daudé wrote: > On 30/09/2018 00:23, Laszlo Ersek wrote: >> 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 <liming....@intel.com> >> Cc: Michael D Kinney <michael.d.kin...@intel.com> >> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1208 >> Contributed-under: TianoCore Contribution Agreement 1.1 >> Signed-off-by: Laszlo Ersek <ler...@redhat.com> > > Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> > >> --- >> 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" >>
Thank you for the review! Laszlo _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
