#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main() {
 char *page,*p;

 page=calloc(1,4);
 page+=4;
 p=page;
 if (page) { // if we change "page" here to "1", the result will be correct
     *((char **)page-1)=page;    // save the address in its previous 4 bytes.
     (*((char ***)page-1))++;    // add 4 to the saved address.
 }
 page=*((char **)page-1);        //"page" should be assigned to the new value.
 printf("page=%08X p=%08X\n",page,p); // with the optimization level -O2/3, the value of page i
s not changed.
 return 0;
}

Release:
3.2.2

Environment:
sunOS 2.8 sparc

How-To-Repeat:
compile with and without O3/O2 options.