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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug middle-end/88173] constant folding of NaN comparison depends on
 order of operands
Date: Tue, 08 Dec 2020 20:48:33 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D88173

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
What should be the exact rules for C++ floating point evaluation that trigg=
er
non-constant expressions?  And shall that depend (like it partly does for G=
CC
currently) on e.g. -ftrapping-math and other command line options?
1.0 / 0.0 - division by zero (for floating point results in Inf)
10000000000000.0 + 0.000000000000001 - inexact (hope this one not)
inf - inf - invalid - non-NaN operands resulting in NaN result
sqrt (-1) - likewise
DBL_MAX * DBL_MAX - overflow
DBL_MIN * DBL_MIN - underflow
NaN + 1.0 - one or both operands NaN resulting in NaN
sNaN + 1.0 - at least one operand sNaN=