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From: "amacleod at redhat dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/108447] [13 Regression] glibc
 math/test-*-iseqsig failures
Date: Wed, 18 Jan 2023 22:21:29 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108447

--- Comment #6 from Andrew Macleod <amacleod at redhat dot com> ---
(In reply to Jakub Jelinek from comment #4)
> I see fold_using_range::relation_fold_and_or
> which sees relation1 VREL_LE and relation2 VREL_GE and !is_and, and becau=
se
> of
> relation_union (relation1, relation2) =3D=3D VREL_VARYING fold it to 1.
> But for floating point comparisons, LE | GE is not always true, it is tru=
e if
> neither operand is NAN, otherwise false.

right.. we're sorting out whether these relations should be created or not,=
 and
if so, how to then verify the result of a union/intersection before committ=
ing
to it.  That validate_relation routine was created for a reason that we are
trying to track down why we arent using it, and if this is an appropriate u=
se,
or if we need something else.=