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From: "amonakov at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/108117] Wrong instruction scheduling on value
 coming from abnormal SSA
Date: Thu, 15 Dec 2022 12:44:26 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108117

--- Comment #9 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
(In reply to Feng Xue from comment #8)

> In another angle, because gcc already model control flow and SSA web for
> setjmp/longjmp, explicit volatile specification is not really needed.

That covers GIMPLE, but after transitioning to RTL, setjmp is not properly
modeled anymore (like in old versions of GCC before Tree-SSA). Many RTL pas=
ses
simply refuse touching the function if it has a setjmp call, but as your
example demonstrated, scheduling still can make a surprising transform.=