https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112572
--- Comment #19 from Sergei Trofimovich <slyfox at gcc dot gnu.org> --- I spent some time poking at the bug and was not able to reproduce it on my toolchain. I was able to get it to fail on gentoo's toolchain and arrived at problems in lib/Target/X86/X86InterleavedAccess.cpp. My theory is that X86InterleavedAccessGroup::decompose() gets compiled incorrectly. `-fPIE` seems to be the flag that triggers gcc to generate slightly incorrect prologue (wrong register is being used). I filed a separate issue in case it's an invalid manual reduction: https://gcc.gnu.org/PR112613