https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117217
--- Comment #12 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Martin Jambor <[email protected]>: https://gcc.gnu.org/g:a202c707bea3ff021b44aa00c0570798a30aae31 commit r17-469-ga202c707bea3ff021b44aa00c0570798a30aae31 Author: Martin Jambor <[email protected]> Date: Tue May 12 14:59:13 2026 +0200 sra: Fix build_user_friendly_ref_for_offset for bit-fields (PR124151) When SRA propagates bit-field propagations across assignments, it first attempts to use build_user_friendly_ref_for_offset to represent the expression of the new accesses and a possible scalar replacement so that if there are any warnings generated for it, they are as nice as we can make them. However, this can lead to situations where, despite that the new access has exactly the same type as the new old one, it accesses a (record or union): field which is just big enough for its precision, whereas the one we want to match has size rounded up to bytes. This causes discrepancy between the recorded size of the new access and the size get_ref_base_and_extent reports for its expr, which trips the verifier. Unlike the previous approach which avoided propagation in the case of bit fields, this patch fixes build_user_friendly_ref_for_offset by making it also track the size it is looking at and the size it is looking for so that it can declare success only if these two also match. Additionally, it reverts the simple bail-out fix for PR 117217 because it is no longer necessary. (I have verified the bug is still fixed though by applying the new fix on top of the last problematic commit.) gcc/ChangeLog: 2026-04-29 Martin Jambor <[email protected]> PR tree-optimization/124151 * tree-sra.cc (build_user_friendly_ref_for_offset): Added parameters CUR_SIZE and EXP_SIZE. Added code passing the correct CUR_SIZE and checking it against EXP_SIZE. Removed unused code for the case when EXP_TYPE was NULL_TREE. (create_artificial_child_access): Adjusted the call to build_user_friendly_ref_for_offset. (propagate_subaccesses_from_rhs): Likewise. (propagate_subaccesses_from_rhs): Removed a check that the size of lchild is a multiple of BITS_PER_UNIT. (propagate_subaccesses_from_lhs): Likewise. gcc/testsuite/ChangeLog: 2026-04-29 Martin Jambor <[email protected]> PR tree-optimization/124151 * gcc.dg/tree-ssa/pr124151.c: New test.
