wrlib/bench.h

   1
   2
   3
   4 inline static void
   5 cycle_bench(int start)
   6 {
   7     static volatile unsigned int start_cycle;
   8
   9     if (start) {
  10         asm volatile
  11             ("pushl %%edx       \n\t"
  12              "rdtsc             \n\t"
  13              "movl %%eax,%0     \n\t"
  14              "cld               \n\t"
  15              "popl %%edx        \n\t"
  16              "nop               \n\t"
  17              "nop               \n\t"
  18              "nop               \n\t"
  19              "nop               \n\t"
  20              "nop               \n\t"
  21              "nop               \n\t"
  22              "nop               \n\t"
  23              "nop               \n\t"
  24              : "=m" (start_cycle) : : "eax", "edx");
  25     } else {
  26         volatile int end;
  27
  28         asm volatile
  29             ("pushl %%edx       \n\t"
  30              "clc               \n\t"
  31              "rdtsc             \n\t"
  32              "movl %%eax, %0    \n\t"
  33              "popl %%edx        \n\t"
  34              : "=m" (end) : : "eax", "edx");
  35
  36         printf("Cycle count = %u\n", end - start_cycle - 68);
  37     }
  38 }
  39
  40
  41
  42 #if 0
  43 // seems linux doesnt allow user progs to exec rdpcm..
  44 inline static void
  45 cache_bench(int start)
  46 {
  47     static int start_cycle;
  48
  49     if (start) {
  50         asm volatile
  51             ("movl $1,%%ecx     \n\t"
  52              "rdpmc             \n\t"
  53              "movl %%eax,%0     \n\t"
  54              : "=m" (start_cycle));
  55     } else {
  56         int end;
  57
  58         asm volatile
  59             ("movl $1,%%ecx     \n\t"
  60              "rdpmc             \n\t"
  61              "movl %%eax,%0"
  62              : "=m" (end));
  63
  64         printf("Cache reloads counted = %i\n", end - start_cycle);
  65     }
  66 }
  67
  68 #endif