MdePkg/Library/BaseLib/Ia32/LShiftU64.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 ;   LShiftU64.nasm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   64-bit left shift function for IA-32
  19 ;
  20 ;------------------------------------------------------------------------------
  21
  22     SECTION .text
  23
  24 ;------------------------------------------------------------------------------
  25 ; UINT64
  26 ; EFIAPI
  27 ; InternalMathLShiftU64 (
  28 ;   IN      UINT64                    Operand,
  29 ;   IN      UINTN                     Count
  30 ;   );
  31 ;------------------------------------------------------------------------------
  32 global ASM_PFX(InternalMathLShiftU64)
  33 ASM_PFX(InternalMathLShiftU64):
  34     mov     cl, [esp + 12]
  35     xor     eax, eax
  36     mov     edx, [esp + 4]
  37     test    cl, 32                      ; Count >= 32?
  38     jnz     .0
  39     mov     eax, edx
  40     mov     edx, [esp + 8]
  41 .0:
  42     shld    edx, eax, cl
  43     shl     eax, cl
  44     ret
  45