[Bug tree-optimization/100636] New: ICE at -Os and above: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.c:88

[Bug tree-optimization/100636] New: ICE at -Os and above: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.c:88

[zhendong.su at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100636

            Bug ID: 100636
           Summary: ICE at -Os and above: tree check: expected class
                    ‘type’, have ‘exceptional’ (error_mark) in
                    useless_type_conversion_p, at gimple-expr.c:88
           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: ---

[547] % 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/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--prefix=/local/suz-local/software/local/gcc-trunk --enable-languages=c,c++
--disable-werror --enable-multilib --with-system-zlib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210517 (experimental) [master revision
e49ff61d419:73ee0e029f5:1dfb5d8ab52c3c76c877077d8d6dc4eaae3c6153] (GCC)
[548] %
[548] % gcctk -O1 -c small.c
[549] %
[549] % gcctk -Os -c small.c
during GIMPLE pass: evrp
small.c: In function ‘b’:
small.c:12:1: internal compiler error: tree check: expected class ‘type’, have
‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.c:88
   12 | }
      | ^
0x60e331 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
        ../../gcc-trunk/gcc/tree.c:8724
0x9eae57 tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
        ../../gcc-trunk/gcc/tree.h:3479
0x9eae57 useless_type_conversion_p(tree_node*, tree_node*)
        ../../gcc-trunk/gcc/gimple-expr.c:88
0xd83552 verify_gimple_comparison
        ../../gcc-trunk/gcc/tree-cfg.c:3515
0xd9a0a0 verify_gimple_in_cfg(function*, bool)
        ../../gcc-trunk/gcc/tree-cfg.c:5443
0xc43b3e execute_function_todo
        ../../gcc-trunk/gcc/passes.c:2042
0xc44a22 execute_todo
        ../../gcc-trunk/gcc/passes.c:2096
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
[550] %
[550] % cat small.c
static int a;
void b() {
  int c;
  while (a) {
    while (a)
      if (c)
        b();
    if (--c)
      while (1)
        ;
  }
}

[Bug tree-optimization/100636] ICE at -Os and above: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.c:88

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100636

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #1 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Duplicate.  The variable c is undefined and is an input to a PHI.

*** This bug has been marked as a duplicate of bug 100512 ***