audk/MdePkg/Library/BaseLib/Ia32/LShiftU64.nasm

46 lines
1.4 KiB
NASM

;------------------------------------------------------------------------------
;
; 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.
;
; Module Name:
;
; LShiftU64.nasm
;
; Abstract:
;
; 64-bit left shift function for IA-32
;
;------------------------------------------------------------------------------
SECTION .text
;------------------------------------------------------------------------------
; UINT64
; EFIAPI
; InternalMathLShiftU64 (
; IN UINT64 Operand,
; IN UINTN Count
; );
;------------------------------------------------------------------------------
global ASM_PFX(InternalMathLShiftU64)
ASM_PFX(InternalMathLShiftU64):
mov cl, [esp + 12]
xor eax, eax
mov edx, [esp + 4]
test cl, 32 ; Count >= 32?
jnz .0
mov eax, edx
mov edx, [esp + 8]
.0:
shld edx, eax, cl
shl eax, cl
ret