https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114936
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Alex Coplan <acop...@gcc.gnu.org>: https://gcc.gnu.org/g:73c8e24b692e691c665d0f1f5424432837bd8c06 commit r15-320-g73c8e24b692e691c665d0f1f5424432837bd8c06 Author: Alex Coplan <alex.cop...@arm.com> Date: Fri May 3 14:12:32 2024 +0000 aarch64: Fix typo in aarch64-ldp-fusion.cc:combine_reg_notes [PR114936] This fixes a typo in combine_reg_notes in the load/store pair fusion pass. As it stands, the calls to filter_notes store any REG_FRAME_RELATED_EXPR to fr_expr with the following association: - i2 -> fr_expr[0] - i1 -> fr_expr[1] but then the checks inside the following if statement expect the opposite (more natural) association, i.e.: - i2 -> fr_expr[1] - i1 -> fr_expr[0] this patch fixes the oversight by swapping the fr_expr indices in the calls to filter_notes. In hindsight it would probably have been less confusing / error-prone to have combine_reg_notes take an array of two insns, then we wouldn't have to mix 1-based and 0-based indexing as well as remembering to call filter_notes in reverse program order. This however is a minimal fix for backporting purposes. gcc/ChangeLog: PR target/114936 * config/aarch64/aarch64-ldp-fusion.cc (combine_reg_notes): Ensure insn iN has its REG_FRAME_RELATED_EXPR (if any) stored in FR_EXPR[N-1], thus matching the correspondence expected by the copy_rtx calls.
