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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/110726] [14 Regression] wrong code on llvm-16 around
 'a |= a == 0'
Date: Tue, 18 Jul 2023 21:42:26 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110726

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Sergei Trofimovich from comment #7)
> Silly question: I would expect -O0 not to perform any simplifications like
> that.  Does `gcc` have a knob to disable `match.pd` templates? Or some of
> them are crucial for correctness?

Some are crucial for correctness usually dealing with c++. you could always=
 use
dbg_cnt to try to narrow down which one is failing.


See=20
https://gcc.gnu.org/git/?p=3Dgcc.git;a=3Dblob;f=3Dgcc/dbgcnt.def;h=3D9e2f1d=
857b49c6c331cc7d1c419eafa0f2403e96;hb=3DHEAD

For on how to use dbg_cnt

match is the counter here.

Also for generic folding -fdump-tree-original-folding will have the debug i=
nfo
on what match pattern was applied during "fold" (of generic).=