test/sysperf/cld1.c

   1 /*
   2  * cld1.c
   3  *
   4  * $DragonFly: src/test/sysperf/cld1.c,v 1.1 2008/05/09 15:49:42 dillon Exp $
   5  */
   6
   7 #include "blib.h"
   8
   9 static __attribute__ ((noinline)) void dummy_with_cld(void);
  10 static __attribute__ ((noinline)) void dummy_without_cld(void);
  11
  12 int
  13 main(int ac, char **av)
  14 {
  15     long long count = 0;
  16     long long max;
  17     char c;
  18     int j;
  19
  20     printf("timing the cld instruction\n");
  21
  22     start_timing();
  23     while (stop_timing(0, NULL) == 0) {
  24         for (j = 0; j < 100; ++j)
  25             getuid();
  26         count += 100;
  27     }
  28     max = count;
  29     start_timing();
  30     for (count = 0; count < max; count += 100) {
  31         for (j = 0; j < 100; ++j)
  32             dummy_without_cld();
  33     }
  34     stop_timing(count, "dummy() - without cld");
  35
  36     start_timing();
  37     for (count = 0; count < max; count += 100) {
  38         for (j = 0; j < 100; ++j)
  39             dummy_with_cld();
  40     }
  41     stop_timing(count, "dummy() - with cld");
  42     return(0);
  43 }
  44
  45 static
  46 __attribute__ ((noinline))
  47 void
  48 dummy_with_cld(void)
  49 {
  50         volatile int i, j, k;
  51
  52         i = 0;
  53         j = 0;
  54         k = 0;
  55         __asm __volatile("cld"::);
  56 }
  57
  58 static
  59 __attribute__ ((noinline))
  60 void
  61 dummy_without_cld(void)
  62 {
  63         volatile int i, j, k;
  64
  65         i = 0;
  66         j = 0;
  67         k = 0;
  68 }