gnu/dist/gdb6/gdb/testsuite/gdb.hp/gdb.aCC/optimize.c

   1 /* Source for debugging optimimzed code test.
   2
   3     cc -g -O -o optimize optimize.c
   4 */
   5 int callee();
   6 int test_opt;
   7
   8 int main()
   9 {
  10    int a,b,c,d,e,f,g,h;
  11
  12    a = 10;;
  13
  14    /* Value propagate
  15     */
  16    b = 2 * a + 1;
  17    c = 3 * b + 2;
  18
  19    /* Re-use expressions
  20     */
  21    d = (2 * a + 1) * (3 * b + 2);
  22    e = (2 * a + 1) * (3 * b + 2);
  23
  24    /* Create dead stores--do lines still exist?
  25     */
  26    d = (2 * a + 1) * (3 * b + 2);
  27    e = (2 * a + 1) * (3 * b + 2);
  28    d = (2 * a + 1) * (3 * b + 2);
  29    e = (2 * a + 1) * (3 * b + 2);
  30
  31    /* Alpha and psi motion
  32     */
  33    if( test_opt ) {
  34        f = e - d;
  35        f = f--;
  36    }
  37    else {
  38        f = e - d;
  39        f = f + d * e;
  40    }
  41
  42    /* Chi and Rho motion
  43     */
  44    h = 0;
  45    do {
  46        h++;
  47        a = b * c + d * e;  /* Chi */
  48        f = f + d * e;
  49        g = f + d * e;      /* Rho */
  50        callee( g+1 );
  51        test_opt = (test_opt != 1);  /* Cycles */
  52    } while( g && h < 10);
  53
  54    /* Opps for tail recursion, unrolling,
  55     * folding, evaporating
  56     */
  57    for( a = 0; a < 100; a++ ) {
  58        callee( callee ( callee( a )));
  59        callee( callee ( callee( a )));
  60        callee( callee ( callee( a )));
  61    }
  62
  63    return callee( test_opt );
  64 }
  65
  66 /* defined late to keep line numbers the same
  67 */
  68 int callee( x )
  69     int x;      /* not used! */
  70 {
  71     test_opt++; /* side effect */
  72
  73     return test_opt;
  74 }
  75
  76 /* end */