[Bug tree-optimization/70396] ICE on valid code at -O3 in 32-bit and 64-bit modes on x86_64-linux-gnu (in immed_wide_int_const, at emit-rtl.c:606)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70396

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-03-24
          Component|rtl-optimization            |tree-optimization
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.

604       /* Allow truncation but not extension since we do not know if the
605          number is signed or unsigned.  */
606       gcc_assert (prec <= v.get_precision ());
607
608       if (len < 2 || prec <= HOST_BITS_PER_WIDE_INT)
609         return gen_int_mode (v.elt (0), mode);
610
(gdb) p prec
$1 = 8
(gdb) p mode
$2 = QImode
(gdb) p v.get_precision ()
$3 = 3

we indeed have

 <integer_type 0x7ffff698b2a0 sizes-gimplified public QI
    size <integer_cst 0x7ffff6887d98 type <integer_type 0x7ffff688b2a0
bitsizetype> constant 8>
    unit size <integer_cst 0x7ffff6887db0 type <integer_type 0x7ffff688b1f8
sizetype> constant 1>
    align 8 symtab 0 alias set 2 canonical type 0x7ffff698b2a0 precision 3 min
<integer_cst 0x7ffff68a42b8 -4> max <integer_cst 0x7ffff699b2a0 3>>
$7 = void

constants in the VECTOR_CST we expand and it has a vector type with
bit-precision element type.