Created attachment 60679 [details] reduced testcase Output: $ x86_64-pc-linux-gnu-gcc -O2 -finstrument-functions-once -favoid-store-forwarding -fnon-call-exceptions -fschedule-insns -mgeneral-regs-only testcase.c -Wno-psabi $ ./a.out Aborted $ x86_64-pc-linux-gnu-gcc -v Using built-in specs. COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-20250307135039-r15-7886-g2427793af1e545-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/15.0.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++ --enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra --disable-bootstrap --with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld --with-as=/usr/bin/x86_64-pc-linux-gnu-as --enable-libsanitizer --disable-libstdcxx-pch --prefix=/repo/gcc-trunk//binary-trunk-20250307135039-r15-7886-g2427793af1e545-checking-yes-rtl-df-extra-nobootstrap-amd64 Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 15.0.1 20250307 (experimental) (GCC)
Miscompilation started with r15-6464-gc86e1c54c6f8771d08a8c070717b80607f990f8a Not sure if we can consider it a regression though, as the -favoid-store-forwarding option has only been added in r15-5640-g1d8de1e93ea00f7797f61cf8e05c47ca86f21f8c
I think this has nothing to do with selective scheduling.
(That's why I removed the blocker.)
(In reply to Jakub Jelinek from comment #1) It'll arguably be a 16 regression as the plan is to enable it by default for some targets.