Performance Management Guide

Example of the second Subroutine

An example (main.c) of a C program using the second() subroutine is as follows:

#include <stdio.h>
double second();
main()
{
      double t1,t2;
 
      t1 = second();
      my_favorite_function();
      t2 = second();
 
     printf("my_favorite_function time: %7.9f\n",t2 - t1);
      exit();
}

An example (main.f) of a FORTRAN program using the second() subroutine is as follows:

      double precision t1
      double precision t2
 
      t1 = second()
      my_favorite_subroutine()
      t2 = second()
      write(6,11) (t2 - t1)
11    format(f20.12)
      end

To compile and use either main.c or main.f, use the following:

xlc -O3 -c second.c timer.s
xlf -O3 -o mainF main.f second.o timer.o
xlc -O3 -o mainC main.c second.o timer.o