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 <[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]>
Reviewed-by: Philippe Mathieu-Daudé <[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" > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
