On 21/12/15 14:59, Bill Schmidt wrote:

On powerpc64, the test passes with -mcpu=power8 (the loop is vectorized as a
reduction); however, without that, similar code is generated to Alpha (the
vectorizer decides the reduction is not worthwhile without SIMD support), and
the test fails; hence, I've XFAILed for powerpc, but I think I could condition
the XFAIL on powerpc64 && !check_p8vector_hw_available, if preferred?

Fun.

Does it work with -mcpu=power7?

Yes, it works with -mcpu=power7, as well as -mcpu=power8, but not e.g. 
-mcpu=power6.

Bill: What GCC DejaGNU incantation would you like to see?

This sounds like more fallout from unaligned accesses being faster on
POWER8 than previous hardware.  What about conditioning the XFAIL on

{ powerpc*-*-* && { ! vect_hw_misalign } }

-- does this work properly?

Not on a stage1 compiler - check_p8vector_hw_available itself requires being able to run executables - I'll check on gcc112. However, both look like they're really about the host (ability to execute an asm instruction), not the target (/ability for gcc to output such an instruction)....

--Alan

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