MdePkg/Library/BaseLib/Ia32/ARShiftU64.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 #   ARShiftU64.asm
  15 #
  16 # Abstract:
  17 #
  18 #   64-bit arithmetic right shift function for IA-32
  19 #
  20 #------------------------------------------------------------------------------
  21
  22 .global _InternalMathARShiftU64
  23
  24 #------------------------------------------------------------------------------
  25 # UINT64
  26 # EFIAPI
  27 # InternalMathARShiftU64 (
  28 #   IN      UINT64                    Operand,
  29 #   IN      UINTN                     Count
  30 #   );
  31 #------------------------------------------------------------------------------
  32 _InternalMathARShiftU64:
  33     movb    12(%esp), %cl
  34     movl    8(%esp), %eax
  35     cltd
  36     testb   $32, %cl
  37     cmovz   %eax, %edx
  38     cmovz   4(%esp), %eax
  39     shrdl   %cl, %edx, %eax
  40     sar     %cl, %edx
  41     ret