1 /*
2 * Copyright (C) 2004-2010 NXP Software
3 * Copyright (C) 2010 The Android Open Source Project
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 #include "LVM_Types.h"
19 #include "LVM_Macros.h"
20 #include "ScalarArithmetic.h"
21 #include "Filter.h"
22
23 /*-------------------------------------------------------------------------*/
24 /* FUNCTION: */
25 /* LVM_Power10 */
26 /* */
27 /* DESCRIPTION: */
28 /* This function calculates 10X using an 11th order polynomial. It uses */
29 /* the following table of 32-bit integer polynomial coefficients: */
30 /* */
31 /* Coefficient Value */
32 /* A0 67102543 */
33 /* A1 309032995 */
34 /* A2 712096127 */
35 /* A3 1092797331 */
36 /* A4 1251625137 */
37 /* A5 1154649460 */
38 /* A6 915654800 */
39 /* A7 597883683 */
40 /* A8 284378230 */
41 /* A9 150262097 */
42 /* A10 124894471 */
43 /* A11 50477244 */
44 /* A12 -2 */
45 /* */
46 /* Y = (A0 + A1*X + A2*X2 + A3*X3 + �.. + AN*xN) << AN+1 */
47 /* */
48 /* */
49 /* PARAMETERS: */
50 /* */
51 /* X is the input variable in Q2.30 format */
52 /* */
53 /* RETURNS: */
54 /* The result of the 10x expansion in Q8.24 format */
55 /*-------------------------------------------------------------------------*/
LVM_Power10(LVM_FLOAT X)56 LVM_FLOAT LVM_Power10(LVM_FLOAT X) {
57 LVM_FLOAT Y, Coefficients[13] = {0.999906f, 2.302475f, 2.652765f, 2.035494f, 1.165667f,
58 0.537676f, 0.213192f, 0.069603f, 0.016553f, 0.004373f,
59 0.001817f, 0.000367f, 0};
60 Y = LVM_Polynomial((LVM_UINT16)11, Coefficients, X);
61 return Y;
62 }
63