gcc and xgetbv

[Rainer Müller]

On 2013-01-25 17:20, Vincent Habchi wrote:
> On 25 janv. 2013, at 16:30, Rainer Müller <raimue at macports.org> wrote:
> 
>> This will still become a problem if we are going to distribute this
>> software as a pre-compiled binary, as the machine running the buildbot
>> might have support for AVX instructions while the end-user might not
>> have that.
> 
> This is already the case with Qt4-Mac, though it has gone unnoticed. The configuration procedure of Qt4 auto-detects SSE/AVX support. At least it says it does, but whether the build process makes use of AVX instructions later remains to me a mystery.

This could still be okay if the actual CPU support is checked at runtime
and a fallback code is provided.

Rainer