[Bug tree-optimization/66958] New: ICE : segfault at -O3 (tree-ssa-threadupdate.c:2672)

[antoine.balestrat at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66958

            Bug ID: 66958
           Summary: ICE : segfault at -O3 (tree-ssa-threadupdate.c:2672)
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: antoine.balestrat at gmail dot com
  Target Milestone: ---

Hello !

The following testcase appears to make a freshly built GCC fail at -O3.

$ xgcc --version
gcc (GCC) 6.0.0 20150721 (experimental)

$ cat test.c
int a, b, c;
void f(void)
{
    int d = 2;
    for(; c; c++)
        if(d &= b ? 2 : a ? : 2)
            while(1);
}


$ xgcc -w -O3 test.c
test.c: In function ‘f’:
test.c:2:6: internal compiler error: Segmentation fault
 void f(void)
      ^
0xb7bd2f crash_signal
        ../../srcdir/gcc/toplev.c:352
0xd64de1 thread_through_all_blocks(bool)
        ../../srcdir/gcc/tree-ssa-threadupdate.c:2672
0xca0d5b execute
        ../../srcdir/gcc/tree-ssa-dom.c:1221
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