[Bug tree-optimization/55964] New: Segmentation fault with -O -ftree-loop-distribution -funswitch-loops

[antoine.balestrat at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55964

             Bug #: 55964
           Summary: Segmentation fault with -O -ftree-loop-distribution
                    -funswitch-loops
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: antoine.balestrat@gmail.com


GCC 4.7.2 and 4.8.0 as of 20130112 fail to compile the following testcase with
the flags -O -ftree-loop-distribution -funswitch-loops.

$ cat segfault.c
int a, b;

void f(void)
{
lbl1:
    for(b = 0; b < 1; b++)
    {
        int u = 1;

        if((b %= 0) * (b ? 0 : a) - 1 && (u /= 0))
        {
            int *q = &u, **k = q;
            goto lbl1;
lbl2:
lbl3:
            a = **k;
            goto lbl2;
        }
    }
    goto lbl3;
}

$ xgcc -w -O -ftree-loop-distribution -funswitch-loops segfault.c
segfault.c: In function ‘f’:
segfault.c:3:6: internal compiler error: Segmentation fault
 void f(void)
      ^
0x8da6df crash_signal
    ../../srcdir/gcc/toplev.c:332
0xa8f61b rename_use_op
    ../../srcdir/gcc/tree-vect-loop-manip.c:53
0xa90777 rename_variables_in_bb(basic_block_def*)
    ../../srcdir/gcc/tree-vect-loop-manip.c:93
0xa9082d rename_variables_in_loop(loop*)
    ../../srcdir/gcc/tree-vect-loop-manip.c:109
0x9447e3 copy_loop_before
    ../../srcdir/gcc/tree-loop-distribution.c:220
0x9447e3 generate_loops_for_partition
    ../../srcdir/gcc/tree-loop-distribution.c:254
0x9447e3 generate_code_for_partition
    ../../srcdir/gcc/tree-loop-distribution.c:539
0x947891 ldist_gen
    ../../srcdir/gcc/tree-loop-distribution.c:1405
0x947891 distribute_loop
    ../../srcdir/gcc/tree-loop-distribution.c:1476
0x947891 tree_loop_distribution
    ../../srcdir/gcc/tree-loop-distribution.c:1548
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with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
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