https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89057
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:b41e6dd50f329b0291457e939d4c0dacd81c82c1 commit r11-6439-gb41e6dd50f329b0291457e939d4c0dacd81c82c1 Author: Richard Sandiford <richard.sandif...@arm.com> Date: Mon Jan 4 11:59:07 2021 +0000 aarch64: Improve vcombine codegen [PR89057] This patch fixes a codegen regression in the handling of things like: __temp.val[0] \ = vcombine_##funcsuffix (__b.val[0], \ vcreate_##funcsuffix (__AARCH64_UINT64_C (0))); \ in the 64-bit vst[234] functions. The zero was forced into a register at expand time, and we relied on combine to fuse the zero and combine back together into a single combinez pattern. The problem is that the zero could be hoisted before combine gets a chance to do its thing. gcc/ PR target/89057 * config/aarch64/aarch64-simd.md (aarch64_combine<mode>): Accept aarch64_simd_reg_or_zero for operand 2. Use the combinez patterns to handle zero operands. gcc/testsuite/ PR target/89057 * gcc.target/aarch64/pr89057.c: New test.
