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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/107608] [13 Regression] Failure on
 fold-overflow-1.c and pr95115.c
Date: Tue, 10 Jan 2023 11:09:00 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107608

--- Comment #18 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
See #c10, I think even with comparisons we need to be careful.  One thing is
whether we can prove one of the branches will be unreachable, we can do that
and replace that branch with __builtin_unreachable, but if trapping math is=
 on,
if a comparison is possibly trapping (operands could be NAN as checked by
frange) or if it is the last use of some SSA_NAME that needs to be kept live
because its computation is possibly trapping, I think we need to preserve t=
he
comparison.
One question is if the default -ftrapping-math should cover all exceptions =
or
just the some subset, invalid/overflow are the worst ones, then underflow a=
nd
least importance is inexact IMHO, pretty much anything can be inexact...=