Code Generation/Exercise 9

The Original Code

Consider the following C code:

<c> static unsigned long a = 10; static double *v; extern void *malloc(unsigned long);

static double *mkvec(unsigned long n) {

 if (n < 1) return (double *)0;
 unsigned long s = sizeof(double);
 double *v = (double *)malloc(n * s);
 return v;

}

double *compute() {

 v = mkvec(a * 4);
 for (unsigned long i = 1; i < a; i++)
   if (v[i] > v[0]) v[i] = 3 * i - 1;
 return v;

} </c>

Assume that the size of pointers, int, and unsigned long is 32 bits and that the size of double is 64 bits.

Postfix Code

The Postfix code for the above code is as follows:

<asm>

</asm>

Compiling and Running

To compile the Postfix code directly, pf2asm can be used (assuming a 32-bit architecture):

• pf2asm compute.pf
• yasm -felf compute.asm