https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115517
--- Comment #17 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by hongtao Liu <liuho...@gcc.gnu.org>: https://gcc.gnu.org/g:a51f2fc0d80869ab079a93cc3858f24a1fd28237 commit r15-3498-ga51f2fc0d80869ab079a93cc3858f24a1fd28237 Author: liuhongt <hongtao....@intel.com> Date: Wed Sep 4 15:39:17 2024 +0800 Handle const0_operand for *avx2_pcmp<mode>3_1. *<avx512>_eq<mode>3<mask_scalar_merge_name>_1 supports nonimm_or_0_operand for op1 and op2, pass_combine would fail to lower avx512 comparision back to avx2 one when op1/op2 is const0_rtx. It's because the splitter only support nonimmediate_operand. Failed to match this instruction: (set (reg/i:V16QI 20 xmm0) (vec_merge:V16QI (const_vector:V16QI [ (const_int -1 [0xffffffffffffffff]) repeated x16 ]) (const_vector:V16QI [ (const_int 0 [0]) repeated x16 ]) (unspec:HI [ (reg:V16QI 105 [ a ]) (const_vector:V16QI [ (const_int 0 [0]) repeated x16 ]) (const_int 0 [0]) ] UNSPEC_PCMP))) The patch extend predicates of the splitter to handles that. gcc/ChangeLog: PR target/115517 * config/i386/sse.md (*avx2_pcmp<mode>3_1): Change predicate of operands[1] and operands[2] from nonimmdiate_operand to nonimm_or_0_operand. gcc/testsuite/ChangeLog: * gcc.target/i386/pr115517.c: New test.
