[Bug middle-end/30338] [4.3 Regression] infinite loop in maybe_canonicalize_comparison

["bergner at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #8 from bergner at gcc dot gnu dot org  2010-07-08 21:50 -------
The test case that was added to the testsuite (pr30338.c) ICE's on
powerpc64-linux with the following options: -Os -m64

Looking at a backtrace, we're hitting this assert in tree.c:build2_stat():

  if (code == POINTER_PLUS_EXPR && arg0 && arg1 && tt)
    gcc_assert (POINTER_TYPE_P (tt) && POINTER_TYPE_P (TREE_TYPE (arg0))
                && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
                && useless_type_conversion_p (sizetype, TREE_TYPE (arg1)));

gdb shows this:

(gdb) frame 1
#1  0x000000001066de84 in build2_stat (code=POINTER_PLUS_EXPR,
tt=0x40000410000, arg0=0x400005112e8, arg1=0x400003104b0)
    at /home/bergner/gcc/gcc-mainline-r161924/gcc/tree.c:3715
3715        gcc_assert (POINTER_TYPE_P (tt) && POINTER_TYPE_P (TREE_TYPE
(arg0))
(gdb) call debug_tree(tt)
 <integer_type 0x40000410000 long unsigned int public unsigned sizetype DI
    size <integer_cst 0x40000310780 type <integer_type 0x400004100a8
bit_size_type> constant 64>
    unit size <integer_cst 0x400003107a8 type <integer_type 0x40000410000 long
unsigned int> constant 8>
    align 64 symtab 0 alias set -1 canonical type 0x40000410000 precision 64
min <integer_cst 0x400003107d0 0> max <integer_cst 0x40000310aa0 -1>>
(gdb) call debug_tree(arg0)
 <ssa_name 0x400005112e8
    type <integer_type 0x40000410000 long unsigned int public unsigned sizetype
DI
        size <integer_cst 0x40000310780 constant 64>
        unit size <integer_cst 0x400003107a8 constant 8>
        align 64 symtab 0 alias set -1 canonical type 0x40000410000 precision
64 min <integer_cst 0x400003107d0 0> max <integer_cst 0x40000310aa0 -1>>
    visited var <var_decl 0x400004f1fe0 D.2060>def_stmt D.2060_43 = ivtmp.27_37
+ D.2059_42;

    version 43>
(gdb) call debug_tree(arg1)
 <integer_cst 0x400003104b0 type <integer_type 0x40000410000 long unsigned int>
constant 1>


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30338