none/tests/x86/looper.c

   1 #include "tests/asm.h"
   2 #include <stdio.h>
   3
   4 int arg = 0;
   5 int res = 0;
   6
   7 extern void loop_plain ( void );
   8 asm("\n"
   9 ".text\n"
  10 VG_SYM(loop_plain) ":\n"
  11 "\tpushl %ecx\n"
  12 "\tmovl $999, %eax\n"
  13 "\tmovl " VG_SYM(arg) ", %ecx\n"
  14
  15 "0:\n"
  16 "\tdecl %eax\n"
  17 "\tdecl %eax\n"
  18 "\tdecl %eax\n"
  19 "\tloop 0b\n"
  20
  21 "\tmovl %eax, " VG_SYM(res) "\n"
  22 "\tpopl %ecx\n"
  23 "\tret\n"
  24 );
  25
  26 extern void loop_ne ( void );
  27 asm("\n"
  28 ".text\n"
  29 VG_SYM(loop_ne) ":\n"
  30 "\tpushl %ecx\n"
  31 "\tmovl $999, %eax\n"
  32 "\tmovl " VG_SYM(arg) ", %ecx\n"
  33
  34 "0:\n"
  35 "\tdecl %eax\n"
  36 "\tdecl %eax\n"
  37 "\tdecl %eax\n"
  38 "\tloopne 0b\n"
  39
  40 "\tmovl %eax, " VG_SYM(res) "\n"
  41 "\tpopl %ecx\n"
  42 "\tret\n"
  43 );
  44
  45 extern void loop_e ( void );
  46 asm("\n"
  47 ".text\n"
  48 VG_SYM(loop_e) ":\n"
  49 "\tpushl %ecx\n"
  50 "\tmovl $999, %eax\n"
  51 "\tmovl " VG_SYM(arg) ", %ecx\n"
  52
  53 "0:\n"
  54 "\tdecl %eax\n"
  55 "\tdecl %eax\n"
  56 "\tdecl %eax\n"
  57 /* invert the Z flag */
  58 "\tpushfl\n"
  59 "\txorl $64, 0(%esp)\n"
  60 "\tpopfl\n"
  61 "\tloope 0b\n"
  62
  63 "\tmovl %eax, " VG_SYM(res) "\n"
  64 "\tpopl %ecx\n"
  65 "\tret\n"
  66 );
  67
  68 int main ( void )
  69 {
  70    res = 0; arg = 10;  loop_plain(); printf("res = %d\n", res);
  71
  72    res = 0; arg = 10;  loop_ne();    printf("res = %d\n", res);
  73    res = 0; arg = 500; loop_ne();    printf("res = %d\n", res);
  74
  75    res = 0; arg = 10;  loop_e();    printf("res = %d\n", res);
  76    res = 0; arg = 500; loop_e();    printf("res = %d\n", res);
  77
  78    return 0;
  79 }