https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97009
--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Martin Jambor <jamb...@gcc.gnu.org>: https://gcc.gnu.org/g:3181f66afc7926950115d9802de1516fba3822a2 commit r9-9326-g3181f66afc7926950115d9802de1516fba3822a2 Author: Martin Jambor <mjam...@suse.cz> Date: Thu Apr 8 18:57:48 2021 +0200 sra: Fix bug in grp_write propagation (PR 97009) SRA represents parts of aggregates which are arrays accessed with unknown index as "unscalarizable regions." When there are two such regions one within another and the outer is only read whereas the inner is written to, SRA fails to propagate that write information across assignments. This means that a second aggregate can contain data while SRA thinks it does not and the pass can wrongly eliminate big chunks of assignment from that second aggregate into a third aggregate, which is what happens in PR 97009. Fixed by checking all children of unscalariable accesses for the grp_write flag. gcc/ChangeLog: 2021-03-31 Martin Jambor <mjam...@suse.cz> PR tree-optimization/97009 * tree-sra.c (access_or_its_child_written): New function. (propagate_subaccesses_from_rhs): Use it instead of a simple grp_write test. gcc/testsuite/ChangeLog: 2021-03-31 Martin Jambor <mjam...@suse.cz> PR tree-optimization/97009 * gcc.dg/tree-ssa/pr97009.c: New test. (cherry picked from commit 19d71674616e6494a60432a2a28adcd762a6c877)
