Arpith Siromoney 💬

Pointer Subtraction

It doesn't seem like there could be much to say about that. The A structure is 7 bytes long so the subtraction implicitly divides by 7. That's about it. But take a look at the assembly language generated when it's compiled with gcc:

movl 4(%esp), %eax
subl 8(%esp), %eax
imull $-1227133513, %eax, %eax

Where is the division by 7? Instead we see multiplication by -1227133513.