https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79460
amker at gcc dot gnu.org changed:
What |Removed |Added
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CC| |amker at gcc dot gnu.org
--- Comment #2 from amker at gcc dot gnu.org ---
(In reply to Raphael C from comment #1)
> After some experimentation (also carried out by Hagen von Eitzen), it seems
> that any limit of at least 72 which is also a multiple of 4 causes the same
> optimisation problem. That is the loop is *not* optimised out in these
> cases.
>
> Perhaps this is an example of one optimisation (SIMD vectorisation)
> conflicting with another?
IMHO, this is "scev propagation" on floating point values if ffast-math? is
enabled. We shouldn't rely on vectorizer to propagate final value, it should
be done somewhere before vectorizer. Thanks.
