User guide

164 CHAPTER 9. THE DESIGN OF CINTCODE
9.2.6 Indirect Assignment
PBYT B%A := C
XPBYT A%B := C
ST A!0 := B
STn 1 ≤ n ≤ 3 A!n := B
ST0Pn 3 ≤ n ≤ 4 P!n!0 := A
ST1Pn 3 ≤ n ≤ 4 P!n!1 := A
STPn 3 ≤ n ≤ 5 P!n!A := B
S0G b G!b!0 := A
S0G1 b G!(b+256)!0 := A
S0GH h G!h!0 := A
These instructions are used in assignments in which % or ! appear as the leading
operator on the left hand side.
9.2.7 Function and Routine Calls
At the moment a func t i on or routine is called the state of the stack is as shown in
figure 9.3. At the entry point of a function or routine the first argument, if any, will
be in register A and i n memory P!3.
E2 En
P
Old stack frame New stack frame
k
Figure 9.3: The moment of calling E(E1,E2,...En)