1 /******************************************************************************
2  *
3  * Copyright (C) 2018 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  * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
19 */
20 /*!
21 ******************************************************************************
22 * \file squrt_interp.c
23 *
24 * \brief
25 *    This file contain square root interpolate function
26 *
27 * \date
28 *
29 * \author
30 *    ittiam
31 *
32 ******************************************************************************
33 */
34 /*****************************************************************************/
35 /* File Includes                                                             */
36 /*****************************************************************************/
37 /* System include files */
38 #include <stdio.h>
39 #include <stdlib.h>
40 
41 /* User include files */
42 #include "ia_type_def.h"
43 #include "defs.h"
44 /* #include "constants.h" */
45 #include "ia_basic_ops32.h"
46 /* #include "ia_basic_ops16.h" */
47 #include "ia_basic_ops40.h"
48 #include "sqrt_interp.h"
49 /* #include "ia_enhaacplus_enc_basicops.h" */
50 #include "common_rom.h"
51 
sqrtFix_interpolate(WORD32 num,WORD * q,const WORD32 * sqrt_tab)52 WORD32 sqrtFix_interpolate(WORD32 num, WORD *q, const WORD32 *sqrt_tab)
53 {
54     WORD32 index, answer, temp, delta, step_size;
55     WORD q_temp = *q;
56     WORD k;
57 
58     if(num == 0)
59         return 0;
60 
61     k = norm32(num);
62     temp = shr32(shl32(num, k), 21);
63     q_temp += k;
64     index = temp & 0x1FF; /* Leave leading 1 */
65     {
66         delta = shl32((shl32(num, k) - shl32(temp, 21)), 10);
67         step_size = sub32(sqrt_tab[index + 1], sqrt_tab[index]);
68         step_size = mult32_shl_sat(step_size, delta); /* Q:Q_SQRT_TAB + 21 + 10 - 31 */
69         answer = add32(sqrt_tab[index], step_size);
70     }
71     if(q_temp & 1)
72     {
73         q_temp -= 1;
74         answer = mult32_shl_sat(answer, INV_SQRT_2_Q31);
75     }
76 
77     q_temp = q_temp >> 1;
78     q_temp += (Q_SQRT_TAB);
79     *q = q_temp;
80 
81     answer >>= 1;
82     *q -= 1;
83 
84     return answer;
85 }
86 
sqrtFix(WORD32 num,WORD * q,const WORD32 * sqrt_tab)87 WORD32 sqrtFix(WORD32 num, WORD *q, const WORD32 *sqrt_tab)
88 {
89     WORD32 index, answer, temp;
90     WORD k;
91     WORD q_temp = *q;
92 
93     if(num == 0)
94         return 0;
95 
96     k = norm32(num);
97     temp = shr32(shl32(num, k), 21);
98     q_temp += k;
99     index = temp & 0x1FF; /* Leave leading 1 */
100     answer = sqrt_tab[index];
101     if(q_temp & 1)
102     {
103         q_temp -= 1;
104         answer = mult32x16in32_shl(answer, INV_SQRT_2_Q15);
105     }
106     q_temp = q_temp >> 1;
107     q_temp += Q_SQRT_TAB;
108     *q = q_temp;
109     return answer;
110 }
111 
112 #ifdef ITT_C6678
113 #pragma CODE_SECTION(sqrtFix_interpolate, "itt_varq_l1pram");
114 #pragma CODE_SECTION(sqrtFix, "itt_varq_l1pram");
115 #endif
116