https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127809
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jeff Law <[email protected]>: https://gcc.gnu.org/g:6db085c8b79ff6fc4265bf8e45605b7992eb85d8 commit r17-5115-g6db085c8b79ff6fc4265bf8e45605b7992eb85d8 Author: Yongqiang Tian <[email protected]> Date: Tue Oct 13 07:04:39 2026 -0600 [PATCH 2/2] jump: Ignore debug insns before BARRIER [PR127809] When delete_related_insns deletes a CODE_LABEL, it walks backward over deleted instructions and notes to find a preceding BARRIER. A DEBUG_INSN stops the walk, so unreachable code can be retained with -g but deleted with -g0. Skip debug insns in the walk. Add a SPARC regression test. GCC's existing gcc.dg/builtin-unreachable-1.c is also a natural trigger on mips-elf at -Os with -g -fno-var-tracking -fcompare-debug. This was found during the PR127808 investigation prompted by Jeff's PR127795 review. The patch is independently applicable, but is ordered after patch 1 because delete_related_insns relies on a BARRIER correctly proving that no path falls through. Tested at GCC revision a02e2004cb707155d5b9b0a82dd428ded0ee2f6f: * With patch 1 applied but without this patch, the new SPARC test fails; with both patches it passes. * The existing gcc.dg/builtin-unreachable-1.c fails on baseline mips-elf at -Os with -g -fno-var-tracking -fcompare-debug and passes with this fix. * A complete sparc-elf `make -k -j8 check-gcc` comparison has no regressions. * Native x86_64-pc-linux-gnu bootstrap and complete `make -k -j24 check` have the same normalized outcomes with and without the two-patch series, as reported in patch 1. * `contrib/check_GNU_style.sh` and `git diff --check` pass. Assisted-by: OpenAI Codex 5.6 Sol, co-reviewed by Claude and Yongqiang Tian. PR rtl-optimization/127809 gcc/ChangeLog: * jump.cc (delete_related_insns): Ignore debug insns when looking for a BARRIER before a deleted label. gcc/testsuite/ChangeLog: * gcc.target/sparc/delete-related-insns-debug.c: New test. Signed-off-by: Yongqiang Tian <[email protected]>
