https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116308
--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-14 branch has been updated by Kito Cheng <k...@gcc.gnu.org>: https://gcc.gnu.org/g:f3ac41f84249d10a1685c73d67e5d071902fcc4c commit r14-11547-gf3ac41f84249d10a1685c73d67e5d071902fcc4c Author: Jeff Law <j...@ventanamicro.com> Date: Sat Jan 18 13:44:33 2025 -0700 [RISC-V][PR target/116308] Fix generation of initial RTL for atomics While this wasn't originally marked as a regression, it almost certainly is given that older versions of GCC would have used libatomic and would not have ICE'd on this code. Basically this is another case where we directly used simplify_gen_subreg when we should have used gen_lowpart. When I fixed a similar bug a while back I noted the code in question as needing another looksie. I think at that time my brain saw the mixed modes (SI & QI) and locked up. But the QI stuff is just the shift count, not some deeper issue. So fixing is trivial. We just replace the simplify_gen_subreg with a gen_lowpart and get on with our lives. Tested on rv64 and rv32 in my tester. Waiting on pre-commit testing for final verdict. PR target/116308 gcc/ * config/riscv/riscv.cc (riscv_lshift_subword): Use gen_lowpart rather than simplify_gen_subreg. gcc/testsuite/ * gcc.target/riscv/pr116308.c: New test.
