Difference between revisions of "Code Generation/Exercise 9"

From Wiki**3

< Code Generation
(Created page with "== 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 lon...")
 
(Compiling and Running)
Line 37: Line 37:
 
To compile the Postfix code directly, [[pf2asm]] can be used:
 
To compile the Postfix code directly, [[pf2asm]] can be used:
  
* pf2asm traverse.pf
+
* pf2asm compute.pf
* yasm -felf traverse.asm
+
* yasm -felf compute.asm
  
 
[[category:Compilers]]
 
[[category:Compilers]]
 
[[category:Teaching]]
 
[[category:Teaching]]

Revision as of 15:07, 5 June 2012

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:

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