MdePkg/Library/BaseLib/Ia32/RShiftU64.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2006, Intel Corporation
   4 # All rights reserved. This program and the accompanying materials
   5 # are licensed and made available under the terms and conditions of the BSD License
   6 # which accompanies this distribution.  The full text of the license may be found at
   7 # http://opensource.org/licenses/bsd-license.php
   8 #
   9 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 #
  12 # Module Name:
  13 #
  14 #   RShiftU64.asm
  15 #
  16 # Abstract:
  17 #
  18 #   64-bit logical right shift function for IA-32
  19 #
  20 #------------------------------------------------------------------------------
  21
  22     .686:
  23     .code:
  24
  25 .global _InternalMathRShiftU64
  26
  27 #------------------------------------------------------------------------------
  28 # UINT64
  29 # EFIAPI
  30 # InternalMathRShiftU64 (
  31 #   IN      UINT64                    Operand,
  32 #   IN      UINTN                     Count
  33 #   );
  34 #------------------------------------------------------------------------------
  35 _InternalMathRShiftU64:
  36     movb    12(%esp), %cl
  37     xorl    %edx, %edx
  38     movl    8(%esp), %eax
  39     testb   $32, %cl
  40     cmovz   %eax, %edx
  41     cmovz   0x4(%esp), %eax
  42     shrdl   %cl, %edx, %eax
  43     shr     %cl, %edx
  44     ret