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

40 lines
1.0 KiB
NASM
Raw Normal View History

;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; 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