void sub1(int32 p0, int16 p1, void *p2)
{
}

Frame:
[p2:4]       <-- ebp+14
[p1:2]       <-- ebp+12
[p0:4]       <-- ebp+8
[retaddr:4]  <-- ebp+4
[oldBP:4]    <-- ebp+0
...
...          <-- esp

use symbolic names

p0 = 8
p1 = 12
p2 = 14

This is bad because any changes to the size of p0
means we have to manually change p1 and p2

p0_size = int16_size
p1_size = char 
p2_size = addr_size

p0 = retaddr + addr_size
p1 = p0 + p0_size
p2 = p1 + p1_size