[PATCH] x86-64: Compile branred.c with -mprefer-vector-width=128 [BZ #24603]

[Joseph Myers]

On Mon, 17 Jun 2019, Florian Weimer wrote:

> * Jeff Law:
> 
> > ISTM that 8, 9, 10 would use the new flag.  11 would issue an error
> > which would trigger a reinvestigation roughly a year from now.
> 
> Do you suggest to put in a #warning for GCC 11, so that people can
> configure with --disable-werror and still build with GCC 11?

I don't think that's a good idea.  We might want e.g. a helper script to 
find places in the source tree to revisit after some given GCC version is 
out / after some given GCC version is no longer supported for building 
glibc.  (E.g. DIAG_IGNORE_NEEDS_COMMENT calls where the version specified 
is now too old to build glibc and so we should see if the warning in 
question still appears with the oldest supported version.)  That implies 
having a limited number of standard ways to mark such places in the 
sources so they can be found later.

-- 
Joseph S. Myers
joseph@codesourcery.com