MdePkg/Library/BaseLib/Ia32/LShiftU64.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   LShiftU64.nasm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   64-bit left shift function for IA-32
  13 ;
  14 ;------------------------------------------------------------------------------
  15
  16     SECTION .text
  17
  18 ;------------------------------------------------------------------------------
  19 ; UINT64
  20 ; EFIAPI
  21 ; InternalMathLShiftU64 (
  22 ;   IN      UINT64                    Operand,
  23 ;   IN      UINTN                     Count
  24 ;   );
  25 ;------------------------------------------------------------------------------
  26 global ASM_PFX(InternalMathLShiftU64)
  27 ASM_PFX(InternalMathLShiftU64):
  28     mov     cl, [esp + 12]
  29     xor     eax, eax
  30     mov     edx, [esp + 4]
  31     test    cl, 32                      ; Count >= 32?
  32     jnz     .0
  33     mov     eax, edx
  34     mov     edx, [esp + 8]
  35 .0:
  36     shld    edx, eax, cl
  37     shl     eax, cl
  38     ret
  39