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Re: Enable EBX for x86 in 32bits PIC code


On 08/28/2014 03:01 PM, Uros Bizjak wrote:
I'd like to avoid X86_TUNE_RELAX_PIC_REG and always treat EBX as an
allocatable register. This way, we can avoid all mess with implicit
xchgs in atomic_compare_and_swap<dwi>_doubleword. Also, having
allocatable EBX would allow us to introduce __builtin_cpuid builtin
and cleanup cpiud.h.

It also makes writing solid inline assembly which has to use %ebx for some reason much easier. We just fixed a glibc bug related to that.

--
Florian Weimer / Red Hat Product Security


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