1 /*

     2 * Copyright (c) 2003 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:  Graphics Extension Library source file

    15  *

    16 */

    17 

    18 

    19 

    20 @ 

    21 @   GfxMultiplyAsm - Multiply a 16:16 fixed point factor into iValue.

    22 @

    23 @       This function multiplies a 16:16 fixed point factor into iValue using

    24 @   an ARM 64 bit multiply instruction.  This is much faster than using the

    25 @   Symbian TInt64 class.  Note that iValue MUST be the first data member of

    26 @   this class.

    27 @

    28 @       r0 = Pointer to iValue (First data item in TFixPt class).

    29 @       r1 = Second factor to multiply.

    30 

    31         .align  2

    32         .globl  GfxMultiplyAsm__6TFixPti

    33         .thumb_func

    34         .code   16

    35 

    36 GfxMultiplyAsm__6TFixPti:

    37 

    38         add     r2, pc, #4            @ Switch from Thumb to ARM execution.

    39         bx      r2

    40         nop

    41 

    42         .align  2

    43         .code   32

    44 

    45         ldr     r2, [r0]              @ r2 = *this, r1 = aVal.iValue.

    46         smull   r3, r2, r1, r2        @ r2:r3 = iValue * aVal.iValue.

    47         mov     r2, r2, lsl #16

    48         orr     r2, r2, r3, lsr #16   @ Extract middle 32 bits from 64 bit product.

    49         str     r2, [r0]              @ Store into iValue.

    50         bx      lr

    51