[Bug tree-optimization/72746] New: gcc ICE at -O2 and above on valid code on x86_64-linux-gnu with “seg fault”

[helloqirun at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72746

            Bug ID: 72746
           Summary: gcc ICE at -O2 and above on valid code on
                    x86_64-linux-gnu with “seg fault”
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: helloqirun at gmail dot com
  Target Milestone: ---

The following valid code causes an ICE when compiled with the current gcc trunk
at  -O2 and -O3 on x86_64-linux-gnu in both 32- and 64-bit modes.


It appears to be a 7 regression.

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 7.0.0 20160728 (experimental) [trunk revision 238824] (GCC) 

$ gcc-trunk -O2 abc.c
abc.c: In function ‘fn1’:
abc.c:12:20: warning: division by zero [-Wdiv-by-zero]
       *d = a *= (c %= 0) > c + (f ? c : e);
                    ^~
abc.c:17:9: warning: division by zero [-Wdiv-by-zero]
       f %= 0;
         ^~
gcc-trunk: internal compiler error: Segmentation fault (program cc1)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

$ cat abc.c
int a, b, f;
long c;
int *d;
unsigned long e;
void fn1 ()
{
  for (; f;)
    {
      for (;;)
        ;
    lblE83BAD08:
      *d = a *= (c %= 0) > c + (f ? c : e);
    }
  if ((a = 0) || (a = b ? 8 : a))
    {
      f = 3;
      f %= 0;
      goto lblE83BAD08;
    }
}