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Re: [PATCH] Fix omp declare simd cloning (PR tree-optimization/60823)

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.

> > OpenMP declare simd results in cloning of the functions for SSE2, AVX and
> > AVX2.
> Ok, that's what I was missing.  ISTM that on Solaris with as/ld,
> -fopenmp should trigger linking with a mapfile like the one currently
> used in some places in the testsuite.  I envision turning this into a
> general facility (-mclear-hwcap; -m is for target-specific options,
> right?) which is automatically turned on by -fopenmp on Solaris.



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