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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug ipa/95769] Constant expression in inline function not optimized
Date: Mon, 22 Jun 2020 07:45:53 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95769

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
If we are going to optimize this at IPA time, I'll note we'd need a separate
middle-end IL evaluation code, because the FE one isn't usable for this (not
even through a langhook), because it relies on the IL being unfolded FE tre=
es
and has all the language imposed restrictions etc.
I think I've mentioned IL evaluation as something useful for loops to be ab=
le
to evaluate all their side-effects and judge if they are small enough (not =
too
much overwritten memory, etc.) to replace the original loop, and if we have=
 it,
using it for functions to whose arguments we propagate constants, perhaps u=
sing
the constexpr as a hint to try somewhat longer, could work.=