MdePkg/Library/BaseLib/Ia32/RShiftU64.S

   1 //
   2 // Include common header file for this module.
   3 //
   4 #include "CommonHeader.h"
   5
   6 #------------------------------------------------------------------------------
   7 #
   8 # Copyright (c) 2006, Intel Corporation
   9 # All rights reserved. This program and the accompanying materials
  10 # are licensed and made available under the terms and conditions of the BSD License
  11 # which accompanies this distribution.  The full text of the license may be found at
  12 # http://opensource.org/licenses/bsd-license.php
  13 #
  14 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  15 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16 #
  17 # Module Name:
  18 #
  19 #   RShiftU64.asm
  20 #
  21 # Abstract:
  22 #
  23 #   64-bit logical right shift function for IA-32
  24 #
  25 #------------------------------------------------------------------------------
  26
  27     .686:
  28     .code:
  29
  30 .globl ASM_PFX(InternalMathRShiftU64)
  31
  32 #------------------------------------------------------------------------------
  33 # UINT64
  34 # EFIAPI
  35 # InternalMathRShiftU64 (
  36 #   IN      UINT64                    Operand,
  37 #   IN      UINTN                     Count
  38 #   );
  39 #------------------------------------------------------------------------------
  40 ASM_PFX(InternalMathRShiftU64):
  41     movb    12(%esp), %cl
  42     xorl    %edx, %edx
  43     movl    8(%esp), %eax
  44     testb   $32, %cl
  45     cmovz   %eax, %edx
  46     cmovz   0x4(%esp), %eax
  47     shrdl   %cl, %edx, %eax
  48     shr     %cl, %edx
  49     ret