Cypress CSC-1200T Guía de usuario descargar pdf (Pagina 105)

Chapter 10. Miscellaneous notes 105

/* Wall clock time in seconds */

return (double) _rtc() * cpcycle * 1.0e-12;

}

This routine can be called either in C/C++ or Fortran. In C/C++ the

syntax is as follows:

extern double SECS(void);

double t1, t2, dt;

t1 = SECS();

... perform calculations ...

t2 = SECS();

dt=t2-t1;

printf("Elapsed time: %f\n",dt);

In Fortran 90:

REAL :: t1, t2, dt

REAL, EXTERNAL :: secs

t1 = secs()

... perform calculations ...

t2 = secs()

dt=t2-t1

WRITE (*,*) ’Elapsed time: ’, dt

To use the SECS routine from Fortran you have to ﬁrst compile the C

routine and then link it with your program:

t3e% cc -c secs.c

t3e% f90 -o prog.x prog.f90 secs.o

10.1.3 The CPU clock timer

You can use the library function ICPUSED() in Fortran codes. This

function returns the CPU time of a task in real-time clock ticks:

INTEGER :: time

time = ICPUSED()

...computation...

time = ICPUSED() - time

WRITE (*,*) ’CPU time in user space = ’, &

time, ’ clock ticks’

C programmers can use the function cpused():

#include <time.h>

time_t before, after, utime;

before = cpused();

1 2 ... 100 101 102 103 104 105 106 107 108 109 110 ... 123 124

Sin comentarios

Cypress CSC-1200T Guía de usuario Pagina 105