[Bug middle-end/71893] gfortran.dg ICEs in gcc/tree-ssa-pre.c; -fcode-hoisting?

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71893

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Value numbering _5 stmt = _5 = (bitsizetype) _4;
Setting value number of _5 to _5 (changed)
...
Value numbering _74 stmt = _74 = (sizetype) _6;
Match-and-simplified (sizetype) _6 to _5
RHS (sizetype) _6 simplified to _5
Setting value number of _74 to _5 (changed)

so it seems sizetype and bitsizetype are actually the same.

Indeed:

(gdb) p sizetype_tab[stk_sizetype]
$1 = (tree_node *) 0x7ffff688c0a8
(gdb) p sizetype_tab[stk_bitsizetype]
$2 = (tree_node *) 0x7ffff688c150
(gdb) p debug_tree ($1)
 <integer_type 0x7ffff688c0a8 sizetype public unsigned DI
    size <integer_cst 0x7ffff6887378 type <integer_type 0x7ffff688c150
bitsizetype> constant 64>
    unit size <integer_cst 0x7ffff6887390 type <integer_type 0x7ffff688c0a8
sizetype> constant 8>
    align 64 symtab 0 alias set -1 canonical type 0x7ffff688c0a8 precision 64
min <integer_cst 0x7ffff68873a8 0> max <integer_cst 0x7ffff6890420
18446744073709551615>>
$3 = void
(gdb) p debug_tree ($2)
 <integer_type 0x7ffff688c150 bitsizetype public unsigned DI
    size <integer_cst 0x7ffff6887378 type <integer_type 0x7ffff688c150
bitsizetype> constant 64>
    unit size <integer_cst 0x7ffff6887390 type <integer_type 0x7ffff688c0a8
sizetype> constant 8>
    align 64 symtab 0 alias set -1 canonical type 0x7ffff688c150 precision 64
min <integer_cst 0x7ffff68873c0 0> max <integer_cst 0x7ffff6890440
18446744073709551615>>
$4 = void


and array_ref_element_size even notices this:

  /* If a size was specified in the ARRAY_REF, it's the size measured
     in alignment units of the element type.  So multiply by that value.  */
  if (aligned_size)
    {
      /* ??? tree_ssa_useless_type_conversion will eliminate casts to
         sizetype from another type of the same width and signedness.  */
      if (TREE_TYPE (aligned_size) != sizetype)
        aligned_size = fold_convert_loc (loc, sizetype, aligned_size);
      return size_binop_loc (loc, MULT_EXPR, aligned_size,
                             size_int (TYPE_ALIGN_UNIT (elmt_type)));

because otherwise size_binop would complain.

I'll fixup in VN/PRE.