Normal Method with 3 args that have a width of "1"
Everything is local vars.

Start:     Vars: |0|1|2|....
...random instructions... 
Store double in slot 2     Result |0|1|2+3|....
(2+3 represents a long taking 2 slots)
 
AOKAY - we can access args 1 and 2 in slots 0 and 1 - good.
 
Swap args 1 and 2 around.
Applies to all instrcuctions referencing the local vars - be it load or store - 2 in width or just 1.
1 => 2
2 => 1

Start:     Vars: |0|1|2|....
...random instructions... 
Store double in slot 1     Result |0|1+2|....
 
The 3rd arg gets deleted and cannot be accessed in the rest of the program.