TCO subtleties with C compilers

test.c

#include <stdio.h>

long acc_normal_rec(long n, long acc)
{
  if (n == 0) return acc;
  long localacc = acc + 1;
  return acc_normal_rec(n-1, localacc);
}

long acc_normal(long n)
{
  long acc = 0;
  return acc_normal_rec(n, acc);
}

long acc_evil_rec(long n, long* acc)
{
  if (n == 0) return *acc;
  long localacc = *acc + 1;
  return acc_evil_rec(n-1, &localacc);
}

long acc_evil(long n)
{
  long acc = 0;
  return acc_evil_rec(n, &acc);
}

int main(void)
{
  printf("%ld", acc_normal(1000));
  printf("%ld", acc_evil(1000));
}