Computers as Components, 2nd Edition

5.4 Basic Compilation Techniques 233

Drawing a control flow graph based on the while form of the loop helps us

understand how to translate it into instructions.

i 5 0;

f 5 0;

i < N

N

Y

Loop

exit

Loop initiation code

Loop test

Loop body

Loop variable update

f 5 f 1 c[i]*x[i];

i 5 i 1 1;

C compilers can generate (using the -s flag) assembler source,which some com-

pilers intersperse with the C code. Such code is a very good way to learn about

both assembly language programming and compilation.

5.4.2 Procedures

Another major code generation problem is the creation of procedures. Generating

code for procedures is relatively straightforward once we know the procedur