reactos/lib/rtl/i386/comparememory_ulong_asm.s

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            comparememory_ulong_asm.S
   5  * PURPOSE:         Memory functions
   6  * PROGRAMMERS:     Patrick Baggett (baggett.patrick@gmail.com)
   7  *                  Alex Ionescu (alex@relsoft.net)
   8  *                  Magnus Olsen (magnusolsen@greatlord.com)
   9  */
  10
  11 .intel_syntax noprefix
  12
  13 /* GLOBALS ****************************************************************/
  14
  15 .globl  _RtlCompareMemoryUlong@12          // [5]  (no bug)
  16
  17 /* FUNCTIONS ***************************************************************/
  18
  19 _RtlCompareMemoryUlong@12:
  20      xor eax,eax
  21      mov ecx, dword [esp + 8 ]   // ecx = Length
  22      shr ecx,2         // Length / sizeof(ULONG)
  23          jz 1f   // if (Length==0) goto .zero
  24
  25      push edi// register that does not to be save eax,ecx,edx to
  26      push ebx// the stack for protetion
  27
  28      mov edi, dword [esp + (4 + 8)]        // edx = Destination
  29      mov eax, dword [esp + (12 + 8)]       // ebx = value
  30      mov ebx,ecx
  31      cld
  32      repe scasd
  33
  34      inc ecx
  35      mov eax,ebx
  36
  37      sub eax,ecx
  38      shl eax,2
  39
  40      pop ebx
  41      pop edi
  42
  43 1:
  44      ret 12