https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123971
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-15 branch has been updated by Robin Dapp <[email protected]>: https://gcc.gnu.org/g:b2d78cceff9747eac780e25f601038dcd7d08ec4 commit r15-10813-gb2d78cceff9747eac780e25f601038dcd7d08ec4 Author: Robin Dapp <[email protected]> Date: Wed Feb 4 12:51:36 2026 +0100 RISC-V: Allow vector modes for xtheadvector. [PR123971] In riscv_vector_mode_supported_any_target_p we disallow any vector mode when TARGET_XTHEADVECTOR. Things go wrong when we check if a permutation for a mode is supported by just looking at the optab (e.g. in forwprop). Then later we try to expand that permutation but cannot find a related int vector mode because we don't allow any vector mode. Strictly speaking, this is fallout from the simplify_vector_constructor changes but it's still a target issue as the common code has done the proper check and we don't live up to the promise of being able to extend a certain mode. This patch just allows all modes in riscv_vector_mode_supported_any_target_p, even for theadvector. PR target/123971 gcc/ChangeLog: * config/riscv/riscv.cc (riscv_vector_mode_supported_any_target_p): Remove TARGET_XTHEADVECTOR. gcc/testsuite/ChangeLog: * gcc.target/riscv/rvv/xtheadvector/pr123971.c: New test. Signed-off-by: Robin Dapp <[email protected]> (cherry picked from commit ecc37444062b408c9e06f811fb3f382ea94f3245)
