https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126787
--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Hongyu Wang <[email protected]>: https://gcc.gnu.org/g:475e9efffaf8de781d7e17b687faf1807e104b01 commit r17-3211-g475e9efffaf8de781d7e17b687faf1807e104b01 Author: Hongyu Wang <[email protected]> Date: Tue Aug 11 16:57:48 2026 +0800 i386: Disallow APX EGPR in FMA4/XOP insns [PR target/126787] FMA4 and XOP instructions are VEX-only, so cannot be promoted to EVEX form. When enforcing -mapxf on such target clone, which is at --with-arch=native plus libgfortran bootstrap on Diamond Rapids or Nova Lake, the fma4 clone may generate unencodable vfmaddps with egpr in mem. Restrict all the FMA4/XOP patterns with replacing 'm' to 'jm' and add gpr16 to the addr attribute to avoid egpr usage under high register pressure. gcc/ChangeLog: PR target/126787 * config/i386/sse.md (*fma_fmadd_<mode>): Use the "jm" to replace "m" constraint and set addr attribute to "gpr16" for vex only alternatives. (*fma_fmsub_<mode>): Likewise. (*fma_fnmadd_<mode>): Likewise. (*fma_fnmsub_<mode>): Likewise. (*fma_fmaddsub_<mode>): Likewise. (*fma_fmsubadd_<mode>): Likewise. (xop_p<macs><ssemodesuffix><ssemodesuffix>): Likewise. (xop_p<macs>dql): Likewise. (xop_p<macs>dqh): Likewise. (xop_p<macs>wd): Likewise. (xop_p<madcs>wd): Likewise. (xop_pcmov_<mode><avxsizesuffix>): Likewise. (xop_phadd<u>bw): Likewise. (xop_phadd<u>bd): Likewise. (xop_phadd<u>bq): Likewise. (xop_phadd<u>wd): Likewise. (xop_phadd<u>wq): Likewise. (xop_phadd<u>dq): Likewise. (xop_phsubbw): Likewise. (xop_phsubwd): Likewise. (xop_phsubdq): Likewise. (xop_pperm): Likewise. (xop_pperm_pack_v2di_v4si): Likewise. (xop_pperm_pack_v4si_v8hi): Likewise. (xop_pperm_pack_v8hi_v16qi): Likewise. (xop_rotl<mode>3): Likewise. (xop_rotr<mode>3): Likewise. (xop_vrotl<mode>3): Likewise. (xop_sha<mode>3): Likewise. (xop_shl<mode>3): Likewise. (xop_frcz<mode>2): Likewise. (*xop_vmfrcz<mode>2): Likewise. (xop_maskcmp<mode>3): Likewise. (xop_maskcmp_uns<mode>3): Likewise. (xop_maskcmp_uns2<mode>3): Likewise. (xop_pcom_tf<mode>3): Likewise. (xop_vpermil2<mode>3): Likewise. gcc/testsuite/ChangeLog: PR target/126787 * gcc.target/i386/pr126787.c: New test.
