https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115751
--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Roger Sayle <sa...@gcc.gnu.org>: https://gcc.gnu.org/g:9a7e3f57e1ab8e6e4cf5ea3c0998aa50c6220579 commit r15-1869-g9a7e3f57e1ab8e6e4cf5ea3c0998aa50c6220579 Author: Roger Sayle <ro...@nextmovesoftware.com> Date: Sat Jul 6 05:24:39 2024 +0100 PR target/115751: Avoid force_reg in ix86_expand_ternlog. This patch fixes a problem with splitting of complex AVX512 ternlog instructions on x86_64. A recent change allows the ternlog pattern to have multiple mem-like operands prior to reload, by emitting any "reloads" as necessary during split1, before register allocation. The issue is that this code calls force_reg to place the mem-like operand into a register, but unfortunately the vec_duplicate (broadcast) form of operands supported by ternlog isn't considered a "general_operand", i.e. supported by all instructions. This mismatch triggers an ICE in the middle-end's force_reg, even though the x86 supports loading these vec_duplicate operands into a vector register in a single (move) instruction. This patch resolves this problem by replacing force_reg with calls to gen_reg_rtx and emit_move (as the i386 backend, unlike the middle-end, knows these will be recognized by recog). 2024-07-06 Roger Sayle <ro...@nextmovesoftware.com> gcc/ChangeLog PR target/115751 * config/i386/i386-expand.cc (ix86_expand_ternlog): Avoid use of force_reg to "reload" non-register operands, as these may contain vec_duplicate (broadcast) operands that aren't supported by force_reg. Use (safer) gen_reg_rtx and emit_move instead.
