[Bug tree-optimization/108582] New: ICE on valid code at -Os and above with "-fno-tree-ccp -fno-tree-dce": tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.cc:87

[zhendong.su at inf dot ethz.ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108582

            Bug ID: 108582
           Summary: ICE on valid code at -Os and above with "-fno-tree-ccp
                    -fno-tree-dce": tree check: expected class ‘type’,
                    have ‘exceptional’ (error_mark) in
                    useless_type_conversion_p, at gimple-expr.cc:87
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

It appears to be a recent regression from 12.2. 

Compiler Explorer: https://godbolt.org/z/91oGh1W8K


[617] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/13.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror
--disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 13.0.1 20230128 (experimental) [master r12-4647-g3f861a5c8fd] (GCC)
[618] %
[618] % gcctk -O3 small.c; ./a.out
[619] %
[619] % gcctk -O3 -fno-tree-ccp -fno-tree-dce small.c
during GIMPLE pass: phiopt
small.c: In function ‘main’:
small.c:3:5: internal compiler error: tree check: expected class ‘type’, have
‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.cc:87
    3 | int main() {
      |     ^~~~
0x6e9981 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
        ../../gcc-trunk/gcc/tree.cc:8959
0xbad6e3 tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
        ../../gcc-trunk/gcc/tree.h:3653
0xbad6e3 useless_type_conversion_p(tree_node*, tree_node*)
        ../../gcc-trunk/gcc/gimple-expr.cc:87
0xfb106c verify_gimple_assign_binary
        ../../gcc-trunk/gcc/tree-cfg.cc:4292
0xfc1897 verify_gimple_assign
        ../../gcc-trunk/gcc/tree-cfg.cc:4829
0xfc1897 verify_gimple_stmt
        ../../gcc-trunk/gcc/tree-cfg.cc:5088
0xfc9448 verify_gimple_in_cfg(function*, bool, bool)
        ../../gcc-trunk/gcc/tree-cfg.cc:5583
0xe5a333 execute_function_todo
        ../../gcc-trunk/gcc/passes.cc:2091
0xe5adb2 execute_todo
        ../../gcc-trunk/gcc/passes.cc:2145
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.
[620] %
[620] % cat small.c
int a, c, d, e, f;
char b;
int main() {
  int g = 1;
  char h[1] = {0};
  while (a) {
    if (f) {
      b = 0;
      if (d)
        continue;
    }
    if (a < 1) {
      g = 0;
      goto L;
    }
  }
  while (c) {
    char *j = h;
    int k;
  L:
    if (e && !g)
      k |= 2 | (*j < 0);
  }
  return 0;
}