https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120090
--- Comment #10 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:f725d6765373f7884a2ea23bc11409b15545958b commit r16-809-gf725d6765373f7884a2ea23bc11409b15545958b Author: Andrew Pinski <quic_apin...@quicinc.com> Date: Mon May 5 09:46:14 2025 -0700 combine: gen_lowpart_no_emit vs CLOBBER [PR120090] The problem here is simplify-rtx.cc expects gen_lowpart_no_emit to return NULL on failure but combine's hook was returning CLOBBER. After r16-160-ge6f89d78c1a7528e93458278, gcc.target/i386/avx512bw-pr103750-2.c started to fail at -m32 due to this as new simplify code would return a RTL with a clobber in it rather than returning NULL. To fix this gen_lowpart_no_emit should return NULL when there was an failure instead of a clobber. This only changes the gen_lowpart_no_emit hook and not the generic gen_lowpart hook as parts of combine just pass gen_lowpart result directly without checking the return value. Bootstrapped and tested on x86_64-linux-gnu. PR rtl-optimization/120090 gcc/ChangeLog: * combine.cc (gen_lowpart_for_combine_no_emit): New function. (RTL_HOOKS_GEN_LOWPART_NO_EMIT): Set to gen_lowpart_for_combine_no_emit. Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
