[Bug rtl-optimization/123118] New: ICE during RTL pass in expand_insn at optabs.cc:8293

[rvismith1115 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123118

            Bug ID: 123118
           Summary: ICE during RTL pass in expand_insn at optabs.cc:8293
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rvismith1115 at gmail dot com
  Target Milestone: ---

The test case is reduced by C-Reduce.
Code link: https://godbolt.org/z/Tbr6h99no

$ riscv64-unknown-elf-g++ -O3 -march=rv64gcv_zvfh  func.cpp
during RTL pass: expand
func.cpp: In function 'void g()':
func.cpp:6:6: internal compiler error: in expand_insn, at optabs.cc:8293
    6 | void g() {
      |      ^
0x3362f4b internal_error(char const*, ...)
        /home/riscv-files/gcc-16-20251123/gcc/diagnostic-global-context.cc:787
0xe647d5 fancy_abort(char const*, int, char const*)
        /home/riscv-files/gcc-16-20251123/gcc/diagnostics/context.cc:1805
0xcd2af8 expand_insn(insn_code, unsigned int, expand_operand*)
        /home/riscv-files/gcc-16-20251123/gcc/optabs.cc:8293
0xcd3463 expand_insn(insn_code, unsigned int, expand_operand*)
        /home/riscv-files/gcc-16-20251123/gcc/optabs.cc:8264
0x157adf9 expand_scatter_store_optab_fn
        /home/riscv-files/gcc-16-20251123/gcc/internal-fn.cc:3676
0x12a9faf expand_call_stmt
        /home/riscv-files/gcc-16-20251123/gcc/cfgexpand.cc:3109
0x12a9faf expand_gimple_stmt_1
        /home/riscv-files/gcc-16-20251123/gcc/cfgexpand.cc:4235
0x12a9faf expand_gimple_stmt
        /home/riscv-files/gcc-16-20251123/gcc/cfgexpand.cc:4382
0x12b085f expand_gimple_basic_block
        /home/riscv-files/gcc-16-20251123/gcc/cfgexpand.cc:6501
0x12b28e7 execute
        /home/riscv-files/gcc-16-20251123/gcc/cfgexpand.cc:7248
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.

$ riscv64-unknown-elf-g++ --version
riscv64-unknown-elf-g++ () 16.0.0 20251123 (experimental)
Copyright (C) 2025 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Reproducer:
long long a;
short c, d;
extern int e[][1][1][1];
extern bool f[][1][4][2];
#include <vector>
void g() {
  for (bool b;;)
    for (signed char h(c); h < 4; h += -4487 - 119) {
      e[b][b][b][b] = std::max(std::min((long long)3, a), (long long)d);
      f[0][0][h][1] = h;
    }
}