[Bug middle-end/92023] [9/10/11/12 Regression] Miscompilation when inlining operator delete[]

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92023

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c++                         |middle-end
      Known to fail|                            |11.2.0, 7.1.0
            Summary|Miscompilation when         |[9/10/11/12 Regression]
                   |inlining operator delete[]  |Miscompilation when
                   |                            |inlining operator delete[]
      Known to work|                            |6.4.0
   Target Milestone|---                         |9.5

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
here is a runtime testcase:
#include <cstddef>
#include <cstdio>
#include <new>

int t = 0;
void use(int* p) __attribute__((noipa,noinline,noclone));
void use(int*){}
void report(int) __attribute__((noipa,noinline,noclone));
void report(int a)
{printf("%d\n",a);t++;}

const int N = 5;
const size_t S = 512;

char objs[N][S];
bool taken[N] = {};

void* operator new[](size_t size) {
    if (size <= S) {
        for (int i = 0; i < N; i++) {
            if (!taken[i]) {
                report(2000 + i);
                taken[i] = true;
                return &objs[i];
            }
        }
    }
    throw std::bad_alloc();
}

void operator delete[](void* ptr) noexcept {
    for (int i = 0; i < N; i++) {
        if (ptr == &objs[i]) {
            report(-2000 - i);
            taken[i] = false;
        }
    }
}

int n = 10;
void test() __attribute__((noinline));
void test() {
    int* a = new int[n];
    int* b = new int[n];
    use(a);
    use(b);
    delete[] b;
    delete[] a;
}

int main(void)
{
    test();
    if (t != 4)
      __builtin_abort();
}