[Bug tree-optimization/54920] New: [4.8 Regression] segfault in tree-ssa-pre.c during Firefox build

["markus at trippelsdorf dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54920

             Bug #: 54920
           Summary: [4.8 Regression] segfault in tree-ssa-pre.c during
                    Firefox build
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: markus@trippelsdorf.de


insert_into_preds_of_block (block=0x7ffff2dba1f8, block@entry=0x7ffff6665dd0,
exprnum=<optimized out>, avail=0x7ffff2dba1f8)
    at /home/markus/gcc/gcc/tree-ssa-pre.c:3085
3085      FOR_EACH_EDGE (pred, ei, block->preds)
(gdb) bt
#0  insert_into_preds_of_block (block=0x7ffff2dba1f8,
block@entry=0x7ffff6665dd0, exprnum=<optimized out>, avail=0x7ffff2dba1f8)
    at /home/markus/gcc/gcc/tree-ssa-pre.c:3085
#1  0x00000000009a760e in do_regular_insertion (block=<optimized out>,
dom=<optimized out>) at /home/markus/gcc/gcc/tree-ssa-pre.c:3385
#2  insert_aux (block=block@entry=0x7ffff6665dd0) at
/home/markus/gcc/gcc/tree-ssa-pre.c:3599
#3  0x00000000009a7008 in insert_aux (block=block@entry=0x7ffff516bb60) at
/home/markus/gcc/gcc/tree-ssa-pre.c:3609
#4  0x00000000009a7008 in insert_aux (block=block@entry=0x7ffff66884e0) at
/home/markus/gcc/gcc/tree-ssa-pre.c:3609
#5  0x00000000009a7008 in insert_aux (block=block@entry=0x7ffff6665750) at
/home/markus/gcc/gcc/tree-ssa-pre.c:3609
#6  0x00000000009a7008 in insert_aux (block=block@entry=0x7ffff66654e0) at
/home/markus/gcc/gcc/tree-ssa-pre.c:3609
#7  0x00000000009a7008 in insert_aux (block=<optimized out>) at
/home/markus/gcc/gcc/tree-ssa-pre.c:3609
#8  0x00000000009a8b9b in insert () at /home/markus/gcc/gcc/tree-ssa-pre.c:3632
#9  do_pre () at /home/markus/gcc/gcc/tree-ssa-pre.c:4707
#10 do_pre () at /home/markus/gcc/gcc/tree-ssa-pre.c:4660
#11 0x00000000007e927a in execute_one_pass (pass=pass@entry=0x112cdc0) at
/home/markus/gcc/gcc/passes.c:2320


markus@x4 src % cat test.i
typedef short __v8hi __attribute__ ((__vector_size__ (16)));
typedef long long __m128i __attribute__ ((__vector_size__ (16)));
int a;
__m128i b;

void
fn1 ()
{
    while (1)
        b = (__m128i) (__v8hi)
    {
        a, 0, 0, 0, 0, 0
    };
}

markus@x4 src % gcc -c -O2 test.i
test.i: In function âfn1â:
test.i:7:1: internal compiler error: Segmentation fault
 fn1 ()
 ^
linux-vdso.so.1: No such file or directory
0x88d3ef crash_signal
        /home/markus/gcc/gcc/toplev.c:335
inconsistent DWARF line number info
0x9a3ee7 insert_into_preds_of_block
        /home/markus/gcc/gcc/tree-ssa-pre.c:3092
0x9a760d do_regular_insertion
        /home/markus/gcc/gcc/tree-ssa-pre.c:3385
0x9a760d insert_aux
        /home/markus/gcc/gcc/tree-ssa-pre.c:3599
0x9a7007 insert_aux
        /home/markus/gcc/gcc/tree-ssa-pre.c:3609
0x9a7007 insert_aux
        /home/markus/gcc/gcc/tree-ssa-pre.c:3609
0x9a8b9a insert
        /home/markus/gcc/gcc/tree-ssa-pre.c:3632
0x9a8b9a do_pre
        /home/markus/gcc/gcc/tree-ssa-pre.c:4707
0x9a8b9a do_pre
        /home/markus/gcc/gcc/tree-ssa-pre.c:4660
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