[PATCH] Avoid bugs like PR68273 to trigger

[Eric Botcazou]

> Not sure what to make of this comment ;)

I guess it was a variant of the usual can-of-worms-opening thing. :-)

> Did you see where we create the SSA name with the overaligned type?

In tree-ssa-pre.c:insert_into_preds_of_block:

(gdb) p debug_pre_expr(expr)
{mem_ref<0B>,yyvsp_1}@.MEM_2

(gdb) p debug_tree(type)
 <pointer_type 0x7ffff6d335e8
    type <record_type 0x7ffff6cea498 Tnode type_0 BLK
        size <integer_cst 0x7ffff6c43678 constant 0>
        unit size <integer_cst 0x7ffff6c43618 constant 0>
        align 8 symtab 0 alias set -1 canonical type 0x7ffff6cea3f0 context 
<translation_unit_decl 0x7ffff6d2e0f0 D.1453>
        pointer_to_this <pointer_type 0x7ffff6ceac78> chain <type_decl 
0x7ffff6c54a18 D.1410>>
    sizes-gimplified unsigned SI
    size <integer_cst 0x7ffff6c435e8 type <integer_type 0x7ffff6c3c150 
bitsizetype> constant 32>
    unit size <integer_cst 0x7ffff6c43600 type <integer_type 0x7ffff6c3c0a8 
sizetype> constant 4>
    align 64 symtab 0 alias set -1 canonical type 0x7ffff6cead20>

  /* Now build a phi for the new variable.  */
  temp = make_temp_ssa_name (type, NULL, "prephitmp");

-- 
Eric Botcazou