[Bug tree-optimization/112939] New: ICE: verify_ssa failed with -O -ftrivial-auto-var-init=zero

[iamanonymous.cs at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112939

            Bug ID: 112939
           Summary: ICE: verify_ssa failed with -O
                    -ftrivial-auto-var-init=zero
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: iamanonymous.cs at gmail dot com
  Target Milestone: ---

Compiler Explorer: https://godbolt.org/z/4q74n5baY

*******************************************************************************
OS and Platform:
$ uname -a:
Linux ubuntu 4.15.0-213-generic #224-Ubuntu SMP Mon Jun 19 13:30:12 UTC 2023
x86_64 x86_64 x86_64 GNU/Linux
*******************************************************************************
gcc version:
$ gcc -v
Using built-in specs.
COLLECT_GCC=/root/gcc_set/202311291030/bin/gcc
COLLECT_LTO_WRAPPER=/root/gcc_set/202311291030/libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/root/gcc_set/202311291030
--with-gmp=/root/build_essential --with-mpfr=/root/build_essential
--with-mpc=/root/build_essential --enable-languages=c,c++ --disable-multilib
--with-sanitizer=address,undefined,thread,leak
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20231129 (experimental) (GCC) 

git version: 99fa0bfd63d97825c4221dcd3123940f1d0e6291
*******************************************************************************
Program:
$ cat mutant.c
int i;

void f (void)
{
  for (;;)
  {
    if (0)
      for (;;)
      {
        int *a;
        int *b = a;

 l1:
        *b = (*b != 0) ? 0 : 2;
      }

    if (i != 0)
      goto l1;
  }
}

*******************************************************************************
Command Lines:
$ gcc -O -ftrivial-auto-var-init=zero mutant.c
mutant.c: In function ‘f’:
mutant.c:20:1: error: definition in block 5 does not dominate use in block 3
   20 | }
      | ^
for SSA_NAME: a_11 in statement:
# VUSE <.MEM_5>
_1 = *a_11;
during GIMPLE pass: fre
mutant.c:20:1: internal compiler error: verify_ssa failed
0x1283220 verify_ssa(bool, bool)
        ../../gcc/gcc/tree-ssa.cc:1203
0xee93a5 execute_function_todo
        ../../gcc/gcc/passes.cc:2095
0xee980e execute_todo
        ../../gcc/gcc/passes.cc:2142
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.