Should we compile x86-64 ld.so with -mno-sse -mno-sse?

H.J. Lu hjl.tools@gmail.com
Wed Oct 31 23:18:00 GMT 2012


On Wed, Oct 31, 2012 at 3:59 PM, Richard Henderson <rth@twiddle.net> wrote:
> On 2012-11-01 03:10, Carlos O'Donell wrote:
>> What use case is there for not wanting to touch SEE in ld.so?
>
> I can only imagine HJL is worried about AVX performance if the
> dynamic linker uses SSE insns.
>

That is not the main reason.  We make sure that ld.so string/memory
functions never touch SSE/AVX registers.  It is not for performance,
but for correctness.  Otherwise callee will get random values in
vector registers,

-- 
H.J.



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