On Tue, 30 Jul 2019, Martin Liška wrote:
On 7/30/19 1:35 PM, Marc Glisse wrote:
+ /* Some delete operators have size as 2nd argument. */
Some delete operators have 3 arguments. From cp/decl.c:
/* operator delete (void *, size_t, align_val_t); */
Yep, I know. The patch I installed expects at least 2 arguments:
+ /* Some delete operators have size as 2nd argument. */
+ if (is_delete_operator && gimple_call_num_args (stmt) >= 2)
True, I guess I am a bit confused why the second argument (which could be
either size or alignment) needs special handling (mark_operand_necessary)
while the third one does not (it is usually a constant).
I tried to experiment to understand, but it is complicated because
including <new> disables the optimization:
#include <new>
void fn1() {
char*p=new char;
delete p;
}
This ICEs with -O -std=c++17:
int a = 64;
std::align_val_t b{64};
void fn1() {
void *s = operator new(a,b);
operator delete(s,8+*(unsigned long*)s,b);
}
--
Marc Glisse
