Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 1 | /*********************************************************************** |
| 2 | Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
| 3 | Redistribution and use in source and binary forms, with or without |
| 4 | modification, are permitted provided that the following conditions |
| 5 | are met: |
| 6 | - Redistributions of source code must retain the above copyright notice, |
| 7 | this list of conditions and the following disclaimer. |
| 8 | - Redistributions in binary form must reproduce the above copyright |
| 9 | notice, this list of conditions and the following disclaimer in the |
| 10 | documentation and/or other materials provided with the distribution. |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 12 | names of specific contributors, may be used to endorse or promote |
| 13 | products derived from this software without specific prior written |
| 14 | permission. |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 18 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 19 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 20 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 21 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 22 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 23 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 24 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 25 | POSSIBILITY OF SUCH DAMAGE. |
| 26 | ***********************************************************************/ |
| 27 | |
| 28 | /*! \file silk_Inlines.h |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 29 | * \brief silk_Inlines.h defines OPUS_INLINE signal processing functions. |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 30 | */ |
| 31 | |
| 32 | #ifndef SILK_FIX_INLINES_H |
| 33 | #define SILK_FIX_INLINES_H |
| 34 | |
| 35 | #ifdef __cplusplus |
| 36 | extern "C" |
| 37 | { |
| 38 | #endif |
| 39 | |
| 40 | /* count leading zeros of opus_int64 */ |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 41 | static OPUS_INLINE opus_int32 silk_CLZ64( opus_int64 in ) |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 42 | { |
| 43 | opus_int32 in_upper; |
| 44 | |
| 45 | in_upper = (opus_int32)silk_RSHIFT64(in, 32); |
| 46 | if (in_upper == 0) { |
| 47 | /* Search in the lower 32 bits */ |
| 48 | return 32 + silk_CLZ32( (opus_int32) in ); |
| 49 | } else { |
| 50 | /* Search in the upper 32 bits */ |
| 51 | return silk_CLZ32( in_upper ); |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | /* get number of leading zeros and fractional part (the bits right after the leading one */ |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 56 | static OPUS_INLINE void silk_CLZ_FRAC( |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 57 | opus_int32 in, /* I input */ |
| 58 | opus_int32 *lz, /* O number of leading zeros */ |
| 59 | opus_int32 *frac_Q7 /* O the 7 bits right after the leading one */ |
| 60 | ) |
| 61 | { |
| 62 | opus_int32 lzeros = silk_CLZ32(in); |
| 63 | |
| 64 | * lz = lzeros; |
| 65 | * frac_Q7 = silk_ROR32(in, 24 - lzeros) & 0x7f; |
| 66 | } |
| 67 | |
| 68 | /* Approximation of square root */ |
| 69 | /* Accuracy: < +/- 10% for output values > 15 */ |
| 70 | /* < +/- 2.5% for output values > 120 */ |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 71 | static OPUS_INLINE opus_int32 silk_SQRT_APPROX( opus_int32 x ) |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 72 | { |
| 73 | opus_int32 y, lz, frac_Q7; |
| 74 | |
| 75 | if( x <= 0 ) { |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | silk_CLZ_FRAC(x, &lz, &frac_Q7); |
| 80 | |
| 81 | if( lz & 1 ) { |
| 82 | y = 32768; |
| 83 | } else { |
| 84 | y = 46214; /* 46214 = sqrt(2) * 32768 */ |
| 85 | } |
| 86 | |
| 87 | /* get scaling right */ |
| 88 | y >>= silk_RSHIFT(lz, 1); |
| 89 | |
| 90 | /* increment using fractional part of input */ |
| 91 | y = silk_SMLAWB(y, y, silk_SMULBB(213, frac_Q7)); |
| 92 | |
| 93 | return y; |
| 94 | } |
| 95 | |
| 96 | /* Divide two int32 values and return result as int32 in a given Q-domain */ |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 97 | static OPUS_INLINE opus_int32 silk_DIV32_varQ( /* O returns a good approximation of "(a32 << Qres) / b32" */ |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 98 | const opus_int32 a32, /* I numerator (Q0) */ |
| 99 | const opus_int32 b32, /* I denominator (Q0) */ |
| 100 | const opus_int Qres /* I Q-domain of result (>= 0) */ |
| 101 | ) |
| 102 | { |
| 103 | opus_int a_headrm, b_headrm, lshift; |
| 104 | opus_int32 b32_inv, a32_nrm, b32_nrm, result; |
| 105 | |
| 106 | silk_assert( b32 != 0 ); |
| 107 | silk_assert( Qres >= 0 ); |
| 108 | |
| 109 | /* Compute number of bits head room and normalize inputs */ |
| 110 | a_headrm = silk_CLZ32( silk_abs(a32) ) - 1; |
| 111 | a32_nrm = silk_LSHIFT(a32, a_headrm); /* Q: a_headrm */ |
| 112 | b_headrm = silk_CLZ32( silk_abs(b32) ) - 1; |
| 113 | b32_nrm = silk_LSHIFT(b32, b_headrm); /* Q: b_headrm */ |
| 114 | |
| 115 | /* Inverse of b32, with 14 bits of precision */ |
| 116 | b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) ); /* Q: 29 + 16 - b_headrm */ |
| 117 | |
| 118 | /* First approximation */ |
| 119 | result = silk_SMULWB(a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */ |
| 120 | |
| 121 | /* Compute residual by subtracting product of denominator and first approximation */ |
| 122 | /* It's OK to overflow because the final value of a32_nrm should always be small */ |
| 123 | a32_nrm = silk_SUB32_ovflw(a32_nrm, silk_LSHIFT_ovflw( silk_SMMUL(b32_nrm, result), 3 )); /* Q: a_headrm */ |
| 124 | |
| 125 | /* Refinement */ |
| 126 | result = silk_SMLAWB(result, a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */ |
| 127 | |
| 128 | /* Convert to Qres domain */ |
| 129 | lshift = 29 + a_headrm - b_headrm - Qres; |
| 130 | if( lshift < 0 ) { |
| 131 | return silk_LSHIFT_SAT32(result, -lshift); |
| 132 | } else { |
| 133 | if( lshift < 32){ |
| 134 | return silk_RSHIFT(result, lshift); |
| 135 | } else { |
| 136 | /* Avoid undefined result */ |
| 137 | return 0; |
| 138 | } |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | /* Invert int32 value and return result as int32 in a given Q-domain */ |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 143 | static OPUS_INLINE opus_int32 silk_INVERSE32_varQ( /* O returns a good approximation of "(1 << Qres) / b32" */ |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 144 | const opus_int32 b32, /* I denominator (Q0) */ |
| 145 | const opus_int Qres /* I Q-domain of result (> 0) */ |
| 146 | ) |
| 147 | { |
| 148 | opus_int b_headrm, lshift; |
| 149 | opus_int32 b32_inv, b32_nrm, err_Q32, result; |
| 150 | |
| 151 | silk_assert( b32 != 0 ); |
| 152 | silk_assert( Qres > 0 ); |
| 153 | |
| 154 | /* Compute number of bits head room and normalize input */ |
| 155 | b_headrm = silk_CLZ32( silk_abs(b32) ) - 1; |
| 156 | b32_nrm = silk_LSHIFT(b32, b_headrm); /* Q: b_headrm */ |
| 157 | |
| 158 | /* Inverse of b32, with 14 bits of precision */ |
| 159 | b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) ); /* Q: 29 + 16 - b_headrm */ |
| 160 | |
| 161 | /* First approximation */ |
| 162 | result = silk_LSHIFT(b32_inv, 16); /* Q: 61 - b_headrm */ |
| 163 | |
| 164 | /* Compute residual by subtracting product of denominator and first approximation from one */ |
| 165 | err_Q32 = silk_LSHIFT( ((opus_int32)1<<29) - silk_SMULWB(b32_nrm, b32_inv), 3 ); /* Q32 */ |
| 166 | |
| 167 | /* Refinement */ |
| 168 | result = silk_SMLAWW(result, err_Q32, b32_inv); /* Q: 61 - b_headrm */ |
| 169 | |
| 170 | /* Convert to Qres domain */ |
| 171 | lshift = 61 - b_headrm - Qres; |
| 172 | if( lshift <= 0 ) { |
| 173 | return silk_LSHIFT_SAT32(result, -lshift); |
| 174 | } else { |
| 175 | if( lshift < 32){ |
| 176 | return silk_RSHIFT(result, lshift); |
| 177 | }else{ |
| 178 | /* Avoid undefined result */ |
| 179 | return 0; |
| 180 | } |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | #ifdef __cplusplus |
| 185 | } |
| 186 | #endif |
| 187 | |
| 188 | #endif /* SILK_FIX_INLINES_H */ |