> On Jun 12, 2016, at 3:56 AM, Steven Newbury <st...@snewbury.org.uk> wrote:
>
> On Fri, 2016-06-10 at 16:05 -0400, Ilia Mirkin wrote:
>> On Fri, Jun 10, 2016 at 3:43 PM, Tim Rowley <timothy.o.rowley@intel.c
>> om> wrote:
>>>
>>> Previously used core-avx-i was for ivybridge;
>>> corei7-avx allows sandybridge.
>>> ---
>>> src/gallium/drivers/swr/Makefile.am | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/src/gallium/drivers/swr/Makefile.am
>>> b/src/gallium/drivers/swr/Makefile.am
>>> index d211f2e..8156cf2 100644
>>> --- a/src/gallium/drivers/swr/Makefile.am
>>> +++ b/src/gallium/drivers/swr/Makefile.am
>>> @@ -124,7 +124,7 @@ COMMON_LDFLAGS = \
>>> lib_LTLIBRARIES = libswrAVX.la libswrAVX2.la
>>>
>>> libswrAVX_la_CXXFLAGS = \
>>> - -march=core-avx-i \
>>> + -march=corei7-avx \
>> Just wondering if it'd be enough to say like
>>
>> -march=x86_64
>> -mavx
>>
>> and add -mavx2 for libswrAVX2.
>>
>> I suspect you've iterated through this 20 times and this has some
>> shortcoming I'm not thinking of, but figured I'd point it out just in
>> case it helps.
>>
>> -ilia
>>
> Maybe I'm the only one who finds it horrible to override -march from
> within project build systems. It causes no end of problems with LTO,
> and results in objects being built inappropriately for the target as
> specified by the builder.
I agree that the way swr is built can be improved and welcome ideas/discussion
for work on the master branch, but for the moment I’m trying to get the 12.0
branch in good shape for swr with non-invasive changes (as we’ve tested the
current setup pretty extensively).
> Why not use function attributes? Either compile a function
> specifically for a particular target, or specifically enable AVX though
> "__attribute__ ((__target__ ("avx")))" (ideally with a fall-back
> implementation detected at run-time when the instruction set isn't
> supported). Even better, have it also protected at build-time by a
> simple check for __AVX__ so the code can be compiled out entirely where
> the package builder has specified -march(=native) as a build flag.
One problem with the function attribute path is that as far as I know, MSVC
does not have a similar feature.
-Tim
>>>
>>> -DKNOB_ARCH=KNOB_ARCH_AVX \
>>> $(COMMON_CXXFLAGS)
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
