[Bug target/123994] [16 Regression] RISC-V rv64gcb: ICE at -O2 during RTL pass: late_combine

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123994

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---

```
during RTL pass: late_combine
t.c: In function ‘backsmith_pure_0’:
t.c:37:1: internal compiler error: Segmentation fault
   37 | }
      | ^
0x448727e internal_error(char const*, ...)
        ../../gcc/diagnostic-global-context.cc:787
0x1e1ed8d crash_signal
        ../../gcc/toplev.cc:325
0x252db82 rtl_ssa::insn_info::is_bb_head() const
        ../../gcc/rtl-ssa/member-fns.inl:641
0x41116f1 rtl_ssa::can_insert_after(rtl_ssa::insn_info*)
        ../../gcc/rtl-ssa/movement.h:68
0x42eda0a
rtl_ssa::function_info::verify_insn_changes(array_slice<rtl_ssa::insn_change*
const>)
        ../../gcc/rtl-ssa/changes.cc:113
0x42667da run
        ../../gcc/late-combine.cc:455
0x4267426 combine_into_uses
        ../../gcc/late-combine.cc:705
0x4267e92 combine_insn
        ../../gcc/late-combine.cc:862
0x4267f8e execute
        ../../gcc/late-combine.cc:885
0x426818f execute
        ../../gcc/late-combine.cc:938
./cc1 t.c -I. -O2 -g0 -march=rv64gcb -mabi=lp64
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
```