MdePkg/Library/BaseLib/Ia32/RRotU64.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   4 ; 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 ;   RRotU64.nasm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   64-bit right rotation for Ia32
  19 ;
  20 ;------------------------------------------------------------------------------
  21
  22     SECTION .text
  23
  24 ;------------------------------------------------------------------------------
  25 ; UINT64
  26 ; EFIAPI
  27 ; InternalMathRRotU64 (
  28 ;   IN      UINT64                    Operand,
  29 ;   IN      UINTN                     Count
  30 ;   );
  31 ;------------------------------------------------------------------------------
  32 global ASM_PFX(InternalMathRRotU64)
  33 ASM_PFX(InternalMathRRotU64):
  34     push    ebx
  35     mov     cl, [esp + 16]
  36     mov     eax, [esp + 8]
  37     mov     edx, [esp + 12]
  38     shrd    ebx, eax, cl
  39     shrd    eax, edx, cl
  40     rol     ebx, cl
  41     shrd    edx, ebx, cl
  42     test    cl, 32                      ; Count >= 32?
  43     jz      .0
  44     mov     ecx, eax                    ; switch eax & edx if Count >= 32
  45     mov     eax, edx
  46     mov     edx, ecx
  47 .0:
  48     pop     ebx
  49     ret
  50