[autovect] [patch] Make store motion use alias oracle

[Dorit Nuzman]

Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> wrote on 14/03/2007
11:18:58:

> Hello,
>
> > Attached is the patch that fix the problem exposed in tree-if-conv.c as
> > was discussed previously.  It was bootstrap and tested on ppc together
> > with the lim patch.
> >
> > OK for autovect?
>
> assuming that you do the required testing, this is OK for mainline as
> well.

in that case, just put it in mainline, and lets synch up the branch with
mainline right after that.

thanks,
dorit

>
> Zdenek
>
> > Thanks,
> > Revital
> >
> > (See attached file: ifcvt_fix_patch_14_3.txt)
> >
> > 2007-03-14  Revital Eres  <eres@il.ibm.com>
> >
> >         * tree-if-conv.c (may_have_side_effect_p): New
> >           function to check if stmt is if-convertible.
> >           (if_convertible_gimple_modify_stmt_p): Call it.
>
> > Index: tree-if-conv.c
> > ===================================================================
> > --- tree-if-conv.c   (revision 122880)
> > +++ tree-if-conv.c   (working copy)
> > @@ -334,9 +334,38 @@
> >    return true;
> >  }
> >
> > +/* Return true if STMT may have certain side effects
> > +   and thus ifcvt can not be applied.  Otherwise return false.  */
> > +static bool
> > +may_have_side_effect_p (tree stmt)
> > +{
> > +  tree lhs, rhs;
> > +
> > +  if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
> > +    return true;
> > +
> > +  if (stmt_ends_bb_p (stmt))
> > +    return true;
> > +
> > +  if (stmt_ann (stmt)->has_volatile_ops)
> > +    return true;
> > +
> > +  lhs = GIMPLE_STMT_OPERAND (stmt, 0);
> > +  if (TREE_CODE (lhs) == SSA_NAME
> > +      && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> > +    return true;
> > +
> > +  rhs = GIMPLE_STMT_OPERAND (stmt, 1);
> > +
> > +  if (TREE_SIDE_EFFECTS (rhs))
> > +    return true;
> > +
> > +  return false;
> > +}
> > +
> >  /* Return true, if M_EXPR is if-convertible.
> >     GIMPLE_MODIFY_STMT is not if-convertible if,
> > -   - It is not movable.
> > +   - It may have certain side effects.
> >     - It could trap.
> >     - LHS is not var decl.
> >    GIMPLE_MODIFY_STMT is part of block BB, which is inside loop LOOP.
> > @@ -352,11 +381,12 @@
> >        print_generic_stmt (dump_file, m_expr, TDF_SLIM);
> >      }
> >
> > -  /* Be conservative and do not handle immovable expressions.  */
> > -  if (movement_possibility (m_expr) == MOVE_IMPOSSIBLE)
> > +  /* Be conservative and do not handle expressions with
> > +     certain side effects.  */
> > +  if (may_have_side_effect_p (m_expr))
> >      {
> >        if (dump_file && (dump_flags & TDF_DETAILS))
> > -   fprintf (dump_file, "stmt is movable. Don't take risk\n");
> > +   fprintf (dump_file, "stmt with side effects. Don't take risk\n");
> >        return false;
> >      }
> >
>