MdePkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / RShiftU64.c

/** @file\r
  64-bit logical right shift function for IA-32\r
\r
  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
\r
\r
\r
/**\r
  Shifts a 64-bit integer right between 0 and 63 bits. This high bits\r
  are filled with zeros. The shifted value is returned.\r
\r
  This function shifts the 64-bit value Operand to the right by Count bits. The\r
  high Count bits are set to zero. The shifted value is returned.\r
\r
  @param  Operand The 64-bit operand to shift right.\r
  @param  Count   The number of bits to shift right.\r
\r
  @return Operand >> Count\r
\r
**/\r
UINT64\r
EFIAPI\r
InternalMathRShiftU64 (\r
  IN      UINT64                    Operand,\r
  IN      UINTN                     Count\r
  )\r
{\r
  _asm {\r
    mov     cl, byte ptr [Count]\r
    xor     edx, edx\r
    mov     eax, dword ptr [Operand + 4]\r
    test    cl, 32\r
    jnz     L0\r
    mov     edx, eax\r
    mov     eax, dword ptr [Operand + 0]\r
L0:\r
    shrd    eax, edx, cl\r
    shr     edx, cl\r
  }\r
}\r
\r