On Thu, Mar 10, 2016 at 01:56:41PM +0100, Jakub Jelinek wrote:
> On Thu, Mar 10, 2016 at 01:46:45PM +0100, Marek Polacek wrote:
> > 2016-03-10 Marek Polacek <pola...@redhat.com>
> >
> > PR c++/70153
> > * cp-gimplify.c (cp_fold): Handle UNARY_PLUS_EXPR.
> >
> > * g++.dg/delayedfold/unary-plus1.C: New test.
> >
> > diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
> > index 6af3760..db23efe 100644
> > --- gcc/cp/cp-gimplify.c
> > +++ gcc/cp/cp-gimplify.c
> > @@ -2009,6 +2009,8 @@ cp_fold (tree x)
> > else
> > x = fold_build1_loc (loc, code, TREE_TYPE (x), op0);
> > }
> > + else if (code == UNARY_PLUS_EXPR)
> > + x = fold_convert (TREE_TYPE (x), op0);
> > else
> > x = fold (x);
> >
>
> Won't this still leak UNARY_PLUS_EXPR into the folded result if
> you could fold the operand of that? It will take the
> x = fold_build1_loc (loc, code, TREE_TYPE (x), op0);
> path...
...of course :(. Testcase for that:
return 2ULL * ((1 + (unsigned long int) +(1 + 0)) * i);
> Wouldn't it be better to just handle case UNARY_PLUS_EXPR:
> separately, and always optimize it away?
> So like:
> case UNARY_PLUS_EXPR:
> loc = EXPR_LOCATION (x);
> op0 = cp_fold_maybe_rvalue (TREE_OPERAND (x, 0), rval_ops);
> if (op0 == error_mark_node)
> x = error_mark_node;
> else
> x = fold_convert_loc (loc, TREE_TYPE (x), op0);
> break;
> or so?
Let's ask Jason. If he prefers this approach, I'll get it done.
Thanks,
Marek
