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From: "slyfox at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/107661] [13 Regression] lambdas get merged
 incorrectly in tempaltes, cause llvm-12 miscompilation
Date: Sat, 12 Nov 2022 18:21:26 +0000
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: 13.0
X-Bugzilla-Keywords: needs-bisection, wrong-code
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107661

--- Comment #2 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
(In reply to Sergei Trofimovich from comment #0)
> Reproducing:
>=20
> $ ./gcc-13-HEAD/bin/gcc -Wall -O0 a.cc -o a
> $ ./gcc-13-HEAD/bin/gcc -Wall -O3 a.cc -o a
> ./bug_HEAD.bash: line 6: 1309437 Illegal instruction     (core dumped) ./a
> $ ./gcc-13-HEAD/bin/gcc -Wall -O0 -DDISABLE_HACK a.cc -o a
> $ ./gcc-13-HEAD/bin/gcc -Wall -O3 -DDISABLE_HACK a.cc -o a

Whoops. Lines miss `&& ./a` execution. The correct reproducer (it's a runti=
me
crash):

$ ./gcc-13-HEAD/bin/gcc -Wall -O3 a.cc -o a && ./a
Illegal instruction (core dumped)

For comparison the other modes are fine:

# remove seemingly unused code with __builtin_trap from visibility:
$ ./gcc-13-HEAD/bin/gcc -Wall -O3 a.cc -o a -DDISABLE_HACK && ./a
<ok>=