audk/MdePkg/Library/BaseLib/Ia32/ARShiftU64.c
Michael D Kinney 9344f09215 MdePkg: Replace BSD License with BSD+Patent License
https://bugzilla.tianocore.org/show_bug.cgi?id=1373

Replace BSD 2-Clause License with BSD+Patent License.  This change is
based on the following emails:

  https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html
  https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html

RFCs with detailed process for the license change:

  V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html
  V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html
  V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
2019-04-09 10:58:13 -07:00

46 lines
1.1 KiB
C

/** @file
64-bit arithmetic right shift function for IA-32.
Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
/**
Shifts a 64-bit integer right between 0 and 63 bits. The high bits
are filled with original integer's bit 63. The shifted value is returned.
This function shifts the 64-bit value Operand to the right by Count bits. The
high Count bits are set to bit 63 of Operand. The shifted value is returned.
@param Operand The 64-bit operand to shift right.
@param Count The number of bits to shift right.
@return Operand arithmetically shifted right by Count.
**/
UINT64
EFIAPI
InternalMathARShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
{
_asm {
mov cl, byte ptr [Count]
mov eax, dword ptr [Operand + 4]
cdq
test cl, 32
jnz L0
mov edx, eax
mov eax, dword ptr [Operand + 0]
L0:
shrd eax, edx, cl
sar edx, cl
}
}