[PATCH] i386: Do not attempt to change stack alignment

Florian Weimer fweimer@redhat.com
Tue May 22 09:26:00 GMT 2018


On 05/22/2018 11:21 AM, Andreas Schwab wrote:
> On Mai 22 2018, fweimer@redhat.com (Florian Weimer) wrote:
> 
>> All supported GCC versions handle stack alignment as expected.
> 
> Can you explain what is expected here?

As required by the current i386 ABI.  Should I put that into the commit 
message?

It seems we used to have an optimization which avoided stack alignment 
for internal calls, but I doubt it was ever completely valid due to 
symbol interposition.  With present compilers, it would not work even 
for internal glibc use due to the scalar-to-vector pass and 
auto-vectorization (at -O3).

Thanks,
Florian



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