Re: [RFA][PATCH] Improve VRP of COND_EXPR_CONDs

[Jeff Law <law at redhat dot com>]

On 04/06/2013 07:08 AM, Steven Bosscher wrote:
> > +      if (!SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop))
> > +       {
> > +         value_range_t *vr = get_value_range (innerop);
> > +
>
> I don't think the SSA_NAME_OCCURS_IN_ABNORMAL_PHI test is necessary,
> get_value_range() will simply return a !VR_RANGE.
It's not necessary -- the code was templated from an unsubmitted related 
change to tree-ssa-forwprop where that test is needed.  I'll remove it 
from this change to tree-vrp.c

> > +          if (vr->type == VR_RANGE
> > +             && operand_equal_p (vr->min, integer_zero_node, 0)
> > +             && operand_equal_p (vr->max, integer_one_node, 0))
> > +           {
>
> Better use range_int_cst_p(vr) followed by compare_tree_int instead of
> operand_equal_p IMHO.
Seems reasonable.

> Print something to dump_file?
Happens via existing machinery.  You'll get a Folded into ... message in 
the detail dumps.  The testcase actually checks for this and also 
verifies the following DCE pass kills the dead code.

jeff