blob: abd3119a7356549f74029d505929868080d0c9f3 [file] [log] [blame]
#define _XOPEN_SOURCE 600 // to enable posix_memalign()
#include <assert.h>
#include <stdlib.h>
#include <malloc.h> // for memalign()
static __attribute__((noinline)) void bar ( int ); /* fwds */
int main(void) {
int sum = 0;
int* x1 = (int*)malloc(sizeof(int));
int* x2 = new int;
int* x3 = new int[10];
int* x4 = (int*)calloc(1, sizeof(int));
int* x5 = (int*)memalign(8, sizeof(int));
int* x6; void* v6;
int res = posix_memalign(&v6, 8, sizeof(int)); x6 = (int*)v6;
assert(NULL != x1 && NULL != x2 && NULL != x3 && NULL != x4 &&
NULL != x5 && 0 == res);
__asm__ __volatile__("":::"memory");
// all underruns
sum += x1[-1]; __asm__ __volatile__("":::"memory"); bar(1);
sum += x2[-1]; __asm__ __volatile__("":::"memory"); bar(2);
sum += x3[-1]; __asm__ __volatile__("":::"memory"); bar(3);
sum += x4[-1]; __asm__ __volatile__("":::"memory"); bar(4);
sum += x5[-1]; __asm__ __volatile__("":::"memory"); bar(5);
sum += x6[-1]; __asm__ __volatile__("":::"memory"); bar(6);
__asm__ __volatile__("":::"memory");
return sum;
}
/* What's with all this __asm__ __volatile__ stuff? Well, it's an
attempt to get gcc-4.1.2 not to claim the memory references that
we're interested in -- x1[-1] through x6[-1] -- appear on different
lines than they really do. By its own rules, gcc can't move code
across an __asm__ __volatile__, and the "memory" item says each one
clobbers memory in some way which gcc can't know, so that probably
(!) persuades it not to carry memory CSEs around either. */
static __attribute__((noinline)) void bar ( int x )
{
__asm__ __volatile__("":::"memory");
}