On Tue, Apr 16, 2019 at 01:25:38PM +0200, Richard Biener wrote:
> So for the parser it's small differences that accumulate, for example
> a lot more comptype calls via null_ptr_cst_p (via char_type_p) via the new
> conversion_null_warnings which is called even without any warning option.
>
> Possible speedup to null_ptr_cst_p is to avoid the expensive char_type_p
> (called 50000 times in GCC 9 vs. only 2000 times in GCC 8):
If we do this (looks like a good idea to me), perhaps we should do also
following (first part just doing what you've done in yet another spot,
moving the less expensive checks first, because null_node_p strips location
wrappers etc.) and the second not to call conversion_null_warnings at all
if we don't want to warn (though, admittedly while
warn_zero_as_null_pointer_constant defaults to 0, warn_conversion_null
defaults to 1).
--- gcc/cp/call.c 2019-04-12 21:47:06.301924378 +0200
+++ gcc/cp/call.c 2019-04-16 13:35:59.779977641 +0200
@@ -6844,8 +6844,9 @@ static void
conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
{
/* Issue warnings about peculiar, but valid, uses of NULL. */
- if (null_node_p (expr) && TREE_CODE (totype) != BOOLEAN_TYPE
- && ARITHMETIC_TYPE_P (totype))
+ if (TREE_CODE (totype) != BOOLEAN_TYPE
+ && ARITHMETIC_TYPE_P (totype)
+ && null_node_p (expr))
{
location_t loc = get_location_for_expr_unwinding_for_system_header
(expr);
if (fn)
@@ -7059,7 +7060,9 @@ convert_like_real (conversion *convs, tr
return cp_convert (totype, expr, complain);
}
- if (issue_conversion_warnings && (complain & tf_warning))
+ if (issue_conversion_warnings
+ && (complain & tf_warning)
+ && (warn_conversion_null || warn_zero_as_null_pointer_constant))
conversion_null_warnings (totype, expr, fn, argnum);
switch (convs->kind)
Jakub
