On 10/05/2015 05:22 PM, Richard Sandiford wrote:
Bernd Schmidt <bschm...@redhat.com> writes:
On 10/05/2015 04:47 PM, Richard Sandiford wrote:
@@ -9536,7 +9520,7 @@ fold_builtin_classify (location_t loc, tree fndecl, tree
arg, int builtin_index)
{
r = TREE_REAL_CST (arg);
if (real_isinf (&r))
- return real_compare (GT_EXPR, &r, &dconst0)
+ return real_compare (GT_EXPR, &r, &dconst<0> ())
? integer_one_node : integer_minus_one_node;
else
return integer_zero_node;
So... are the templates magic enough not to make us create a new
temporary every time this is used?
Yeah, the static variables become comdat objects keyed off the full name
(dconst<...>::value). They're shared between calls and between TUs.
Hmm. And since you're returning a reference, taking the address works.
The whole thing is subtle enough that it deserves a comment. Since this
kind of thing is something I don't like about C++ (simple-looking code
expanding into non-obvious behaviour) I'm not going to ack this patch,
but if someone else wants to, that's fine.
I do believe you still have some code growth since the inline dconst
function always expands code that will initialize the constant. IMO
that's not desirable.
Bernd
