Jakub Jelinek <ja...@redhat.com> writes:
> On Thu, May 15, 2014 at 02:37:33PM +0200, Rainer Orth wrote:
>> > If OpenMP declare simd doesn't work on Solaris/x86 (due to the bogus hw cap
>> > stuff), then supposedly vect_simd_clones effective target should fail
>> > there.
>>
>> I don't think it's bogus: it guards against a similar kind of problems
>> as symbol versioning. There, programs that depend on a missing
>> interface don't start to run instead of crashing in the middle of
>> execution when a function is missing. With hwcap, programs depending on
>> insns not supported by the host don't even start running instead of
>> crashing later on.
>
> Runtime selection of code is very common though, which is why I think that
> whole idea of hw cap flags checking is bogus.
That may be changing, but what I observe far more often is code compiled
on one system with -mcpu/arch=native, later you try to execute it on a
different system and it crashes, giving no real indication why.
Rainer
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Rainer Orth, Center for Biotechnology, Bielefeld University
