[FFmpeg-devel] [PATCH] Fix ff_imdct_calc_sse() on gcc-4.6.
Sun Jan 30 23:40:52 CET 2011
On Sun, Jan 30, 2011 at 2:13 AM, Reimar D?ffinger
<Reimar.Doeffinger at gmx.de> wrote:
> On Sun, Jan 30, 2011 at 01:22:05AM -0800, Alex Converse wrote:
>> On Sun, Jan 30, 2011 at 1:08 AM, Alex Converse <alex.converse at gmail.com> wrote:
>> > Gcc 4.6 only preserves the first value when using a vector with an "m"
>> > constraint.
>> > ---
>> > ?libavcodec/x86/fft_sse.c | ? ?4 ++--
>> > ?1 files changed, 2 insertions(+), 2 deletions(-)
>> oops this generates an extra indirection. Those of you who like to
>> defend inline asm, please step up and make some suggestions.
> Use what would be your _only_ option (conceptually, not in implementation
> of course) if you didn't use inline asm:
> MANGLE and change DECLARE_ALIGNED to DECLARE_ASM_CONST
> There's also the option of a gcc bug report, I have some doubts that is
> a valid optimization (though there are constraints to make gcc load
> directly into a xmm register, but both that and the current code have
> needlessly unpredictable performance).
With MANGLE this time.
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