6. Code Example

From the book, Chapter 18 pages 9-10:

int array[1000]; // 1000 = 0x3e8
...
for (i = 0; i < 1000; i++)
  array[i] = 0;

gcc -o array array.c -Wall -O
objdump -d array

1024 movl $0x0,(%edi,%eax,4)
1028 incl %eax
1032 cmpl $0x03e8,%eax
1036 jne  0x1024

Compare using gcc-8.2.0 on Linux x86_64:

int main(void) {
  int array[1000];
  for( int i = 0; i < 1000; ++i) array[i] = 0;
  return array[10];
}

gcc -m32 -S array.c

array.s:
...
	movl	$0, -4(%ebp)
	jmp	.L2
.L3:
	movl	-4(%ebp), %eax
	movl	$0, -4004(%ebp,%eax,4)
	addl	$1, -4(%ebp)
.L2:
	cmpl	$999, -4(%ebp)
	jle	.L3
...