[Bug target/127547] [17 Regression] ICE: in spill_subreg_move, at config/riscv/riscv.cc:5378 at -O1 since r17-3908

[bergner at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127547

--- Comment #3 from Peter Bergner <bergner at gcc dot gnu.org> ---
Interestingly, if I add a -fdump-rtl-expand, then the ICE turns into a SEGV
dumping out the rtl.

Here's the stack trace from the normal (no rtl dump) ICE:

(gdb) frame 1
#1  0x00000000027026ec in spill_subreg_move (dest=0x7ffff76b1f18,
src=0x7ffff76b8450)
    at
/home/bergner/gcc/gcc-fsf-mainline-pr127547/gcc/config/riscv/riscv.cc:5369
5369          gcc_assert (known_eq (SUBREG_BYTE (src), 0));
(gdb) pr dest
(reg:TI 137 [ _12+16 ])
(gdb) pr src
(subreg:TI (reg/v:V16HI 151 [ w ]) 16)
(gdb) p SUBREG_BYTE (src)
$2 = {coeffs = {16, 0}}