Array bounds checking with C????

[Walter Bright]

In comp.lang.c, campbell at redsox.bsw.com (Larry Campbell) writes:
| Are there actually any current compilers out there that are so stupid 
| that they generate substantially different code for the following two 
| code fragments? 
| 
|     /* Fragment 1 */
|     for (p = array; p < &array[ARRAY_SIZE]; p++)
| 	*p = '\0';		/* changed from *p++ = 0;	*/
| 
|     /* Fragment 2 */
|     for (i = 0; i < ARRAY_SIZE; i++)
| 	array[i] = '\0';

The optimization that converts 2 to 1 is called 'strength reduction'
with 'loop induction variable elimination'. It is an advanced capability
of global optimizing compilers, and few compilers do it. Zortech C/C++
does this optimization when it is compiling with full optimization.