/** @file 64-bit left shift function for IA-32. Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at http://opensource.org/licenses/bsd-license.php. THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ /** Shifts a 64-bit integer left between 0 and 63 bits. The low bits are filled with zeros. The shifted value is returned. This function shifts the 64-bit value Operand to the left by Count bits. The low Count bits are set to zero. The shifted value is returned. @param Operand The 64-bit operand to shift left. @param Count The number of bits to shift left. @return Operand << Count **/ UINT64 EFIAPI InternalMathLShiftU64 ( IN UINT64 Operand, IN UINTN Count ) { _asm { mov cl, byte ptr [Count] xor eax, eax mov edx, dword ptr [Operand + 0] test cl, 32 // Count >= 32? jnz L0 mov eax, edx mov edx, dword ptr [Operand + 4] L0: shld edx, eax, cl shl eax, cl } }