Code Generation for Statements

The function genc(code) generates code for a statement. There are only a few kinds of statements:

1. PROGN
   For each argument statement, generate code.

2. :=
   Generate the right-hand side into a register using genarith. Then store the register into the location specified by the left-hand side.

3. GOTO
   Generate a Jump (branch) to the label number.

4. LABEL
   Generate a Label with the label number.

5. IF
   (IF c p1 p2) can be compiled as:
   IF c GOTO L1;
   p2; GOTO L2; L1: p1; L2:
   Optimizations are discussed later.

6. FUNCALL
   Compile short intrinsic functions in-line. For others, generate subroutine calls.