https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125308
--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-16 branch has been updated by Jakub Jelinek <[email protected]>: https://gcc.gnu.org/g:d10ef83766fc886bb76c1aadae2e5dd760e155f0 commit r16-8917-gd10ef83766fc886bb76c1aadae2e5dd760e155f0 Author: Jakub Jelinek <[email protected]> Date: Fri May 15 09:55:40 2026 +0200 i386: Fix up *minmax<mode>3_4 [PR125308] IEEE min/max are not commutative and in the pattern (define_insn "ieee_<ieee_maxmin><mode>3<mask_name><round_saeonly_name>" [(set (match_operand:VFH 0 "register_operand" "=x,v") (unspec:VFH [(match_operand:VFH 1 "register_operand" "0,v") (match_operand:VFH 2 "<round_saeonly_nimm_predicate>" "xBm,<round_saeonly_constraint>")] IEEE_MAXMIN))] the first operand is a register and only the second one is register/memory. Now, the *minmax<mode>3_3 define_insn_and_split does rtx tmp = force_reg (<MODE>mode, operands[3]); rtvec v = gen_rtvec (2, tmp, operands[2]); operands[5] = gen_rtx_UNSPEC (<MODE>mode, v, u); where operands[3] is the const0_operand, so operands[2] can there be a memory, but in the *minmax<mode>3_4 case rtx tmp = force_reg (<MODE>mode, operands[3]); rtvec v = gen_rtvec (2, operands[2], tmp); operands[5] = gen_rtx_UNSPEC (<MODE>mode, v, u); operands[2] goes into the operand which must be a REG, so it is incorrect to split it into something that won't work. Now, I've tried both disabling the define_insn_and_split and the following patch, the former to the latter results in movaps a, %xmm0 pxor %xmm1, %xmm1 - cmpltps %xmm0, %xmm1 - andps %xmm1, %xmm0 + maxps %xmm1, %xmm0 movaps %xmm0, a ret on the testcase, so I think it is better to match it and force_reg (it is a pre-reload splitter) than change "nonimmediate_operand" to "register_operand" because it won't match in that case. 2026-05-15 Jakub Jelinek <[email protected]> PR target/125308 * config/i386/sse.md (*minmax<mode>3_4): Force also operands[2] into a REG. * gcc.target/i386/pr125308.c: New test. (cherry picked from commit c96589414eeb0e46d9fe9cc1d562e048230b5f67)
