[Bug tree-optimization/45522] PRE misses oppurtunity for statement folding.

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45522

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2010-10-28 20:41:46         |2011-08-09 20:41:46
            Summary|VRP misses oppurtunity for  |PRE misses oppurtunity for
                   |statement folding.          |statement folding.

--- Comment #13 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-09 15:05:44 UTC ---
comment #3 works now:

Folding statement: D.2751_6 = tree_code_type[D.2750_5];
Folded into: D.2751_6 = 2;

I can't see how comment #4 should work - in VRP1 we end up with

<bb 2>:
  goto <bb 4>;

<bb 3>:
  D.2737_5 = BIT_FIELD_REF <*tinfo_4(D), 8, 0>;
  D.2738_6 = D.2737_5 & 1;
  fancy_abort ("../../gcc/cp/rtti.c", 1529, &__FUNCTION__);
  ix_11 = ix_1 + 1;

<bb 4>:
  # ix_1 = PHI <0(2), ix_11(3)>
  D.2742_3 = fundamentals[ix_1];
  if (D.2742_3 != 0B)
    goto <bb 3>;
  else
    goto <bb 5>;

<bb 5>:
  return;

so I suppose an earlier patch already did the folding.

I can confirm comment #5.

Removing VRP reference from the summary.