none/tests/amd64/jrcxz.c

   1
   2 #include <stdio.h>
   3
   4 typedef unsigned long long int ULong;
   5 typedef unsigned           int UInt;
   6
   7 ULong arg64, res64;
   8
   9 extern void foo64 ( void );
  10 asm("\n"
  11 ".text\n"
  12 "foo64:\n"
  13 "\tpushq %rcx\n"
  14
  15 "\tmovq $0, %rax\n"
  16 "\tmovq arg64, %rcx\n"
  17
  18 "Lagain64:\n"
  19 "\taddq $177, %rax\n"
  20 "\tdecq %rcx\n"
  21 "\tjrcxz Lout64\n"
  22 "\tjmp Lagain64\n"
  23
  24 "Lout64:\n"
  25 "\tmovq %rax, res64\n"
  26
  27 "\tpopq %rcx\n"
  28 "\tret\n"
  29 ".previous\n"
  30 );
  31
  32
  33 UInt arg32, res32;
  34
  35 extern void foo32 ( void );
  36 asm("\n"
  37 ".text\n"
  38 "foo32:\n"
  39 "\tpushq %rcx\n"
  40
  41 "\tmovq $0, %rax\n"
  42 "\tmovl arg32, %ecx\n"
  43
  44 "Lagain32:\n"
  45 "\taddq $177, %rax\n"
  46 "\tdecl %ecx\n"
  47 "\tjecxz Lout32\n"
  48 "\tjmp Lagain32\n"
  49
  50 "Lout32:\n"
  51 "\tmovl %eax, res32\n"
  52
  53 "\tpopq %rcx\n"
  54 "\tret\n"
  55 ".previous\n"
  56 );
  57
  58
  59
  60 int main ( void )
  61 {
  62   arg64 = 100;
  63   res64 = 0;
  64   foo64();
  65   printf("%lld\n", res64);
  66
  67   arg32 = 1234;
  68   res32 = 0;
  69   foo32();
  70   printf("%d\n", res32);
  71
  72   return 0;
  73 }