cannam@154: /*********************************************************************** cannam@154: Copyright (c) 2006-2011, Skype Limited. All rights reserved. cannam@154: Redistribution and use in source and binary forms, with or without cannam@154: modification, are permitted provided that the following conditions cannam@154: are met: cannam@154: - Redistributions of source code must retain the above copyright notice, cannam@154: this list of conditions and the following disclaimer. cannam@154: - Redistributions in binary form must reproduce the above copyright cannam@154: notice, this list of conditions and the following disclaimer in the cannam@154: documentation and/or other materials provided with the distribution. cannam@154: - Neither the name of Internet Society, IETF or IETF Trust, nor the cannam@154: names of specific contributors, may be used to endorse or promote cannam@154: products derived from this software without specific prior written cannam@154: permission. cannam@154: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" cannam@154: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE cannam@154: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE cannam@154: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE cannam@154: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR cannam@154: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF cannam@154: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS cannam@154: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN cannam@154: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) cannam@154: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE cannam@154: POSSIBILITY OF SUCH DAMAGE. cannam@154: ***********************************************************************/ cannam@154: cannam@154: /*! \file silk_Inlines.h cannam@154: * \brief silk_Inlines.h defines OPUS_INLINE signal processing functions. cannam@154: */ cannam@154: cannam@154: #ifndef SILK_FIX_INLINES_H cannam@154: #define SILK_FIX_INLINES_H cannam@154: cannam@154: #ifdef __cplusplus cannam@154: extern "C" cannam@154: { cannam@154: #endif cannam@154: cannam@154: /* count leading zeros of opus_int64 */ cannam@154: static OPUS_INLINE opus_int32 silk_CLZ64( opus_int64 in ) cannam@154: { cannam@154: opus_int32 in_upper; cannam@154: cannam@154: in_upper = (opus_int32)silk_RSHIFT64(in, 32); cannam@154: if (in_upper == 0) { cannam@154: /* Search in the lower 32 bits */ cannam@154: return 32 + silk_CLZ32( (opus_int32) in ); cannam@154: } else { cannam@154: /* Search in the upper 32 bits */ cannam@154: return silk_CLZ32( in_upper ); cannam@154: } cannam@154: } cannam@154: cannam@154: /* get number of leading zeros and fractional part (the bits right after the leading one */ cannam@154: static OPUS_INLINE void silk_CLZ_FRAC( cannam@154: opus_int32 in, /* I input */ cannam@154: opus_int32 *lz, /* O number of leading zeros */ cannam@154: opus_int32 *frac_Q7 /* O the 7 bits right after the leading one */ cannam@154: ) cannam@154: { cannam@154: opus_int32 lzeros = silk_CLZ32(in); cannam@154: cannam@154: * lz = lzeros; cannam@154: * frac_Q7 = silk_ROR32(in, 24 - lzeros) & 0x7f; cannam@154: } cannam@154: cannam@154: /* Approximation of square root */ cannam@154: /* Accuracy: < +/- 10% for output values > 15 */ cannam@154: /* < +/- 2.5% for output values > 120 */ cannam@154: static OPUS_INLINE opus_int32 silk_SQRT_APPROX( opus_int32 x ) cannam@154: { cannam@154: opus_int32 y, lz, frac_Q7; cannam@154: cannam@154: if( x <= 0 ) { cannam@154: return 0; cannam@154: } cannam@154: cannam@154: silk_CLZ_FRAC(x, &lz, &frac_Q7); cannam@154: cannam@154: if( lz & 1 ) { cannam@154: y = 32768; cannam@154: } else { cannam@154: y = 46214; /* 46214 = sqrt(2) * 32768 */ cannam@154: } cannam@154: cannam@154: /* get scaling right */ cannam@154: y >>= silk_RSHIFT(lz, 1); cannam@154: cannam@154: /* increment using fractional part of input */ cannam@154: y = silk_SMLAWB(y, y, silk_SMULBB(213, frac_Q7)); cannam@154: cannam@154: return y; cannam@154: } cannam@154: cannam@154: /* Divide two int32 values and return result as int32 in a given Q-domain */ cannam@154: static OPUS_INLINE opus_int32 silk_DIV32_varQ( /* O returns a good approximation of "(a32 << Qres) / b32" */ cannam@154: const opus_int32 a32, /* I numerator (Q0) */ cannam@154: const opus_int32 b32, /* I denominator (Q0) */ cannam@154: const opus_int Qres /* I Q-domain of result (>= 0) */ cannam@154: ) cannam@154: { cannam@154: opus_int a_headrm, b_headrm, lshift; cannam@154: opus_int32 b32_inv, a32_nrm, b32_nrm, result; cannam@154: cannam@154: silk_assert( b32 != 0 ); cannam@154: silk_assert( Qres >= 0 ); cannam@154: cannam@154: /* Compute number of bits head room and normalize inputs */ cannam@154: a_headrm = silk_CLZ32( silk_abs(a32) ) - 1; cannam@154: a32_nrm = silk_LSHIFT(a32, a_headrm); /* Q: a_headrm */ cannam@154: b_headrm = silk_CLZ32( silk_abs(b32) ) - 1; cannam@154: b32_nrm = silk_LSHIFT(b32, b_headrm); /* Q: b_headrm */ cannam@154: cannam@154: /* Inverse of b32, with 14 bits of precision */ cannam@154: b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) ); /* Q: 29 + 16 - b_headrm */ cannam@154: cannam@154: /* First approximation */ cannam@154: result = silk_SMULWB(a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */ cannam@154: cannam@154: /* Compute residual by subtracting product of denominator and first approximation */ cannam@154: /* It's OK to overflow because the final value of a32_nrm should always be small */ cannam@154: a32_nrm = silk_SUB32_ovflw(a32_nrm, silk_LSHIFT_ovflw( silk_SMMUL(b32_nrm, result), 3 )); /* Q: a_headrm */ cannam@154: cannam@154: /* Refinement */ cannam@154: result = silk_SMLAWB(result, a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */ cannam@154: cannam@154: /* Convert to Qres domain */ cannam@154: lshift = 29 + a_headrm - b_headrm - Qres; cannam@154: if( lshift < 0 ) { cannam@154: return silk_LSHIFT_SAT32(result, -lshift); cannam@154: } else { cannam@154: if( lshift < 32){ cannam@154: return silk_RSHIFT(result, lshift); cannam@154: } else { cannam@154: /* Avoid undefined result */ cannam@154: return 0; cannam@154: } cannam@154: } cannam@154: } cannam@154: cannam@154: /* Invert int32 value and return result as int32 in a given Q-domain */ cannam@154: static OPUS_INLINE opus_int32 silk_INVERSE32_varQ( /* O returns a good approximation of "(1 << Qres) / b32" */ cannam@154: const opus_int32 b32, /* I denominator (Q0) */ cannam@154: const opus_int Qres /* I Q-domain of result (> 0) */ cannam@154: ) cannam@154: { cannam@154: opus_int b_headrm, lshift; cannam@154: opus_int32 b32_inv, b32_nrm, err_Q32, result; cannam@154: cannam@154: silk_assert( b32 != 0 ); cannam@154: silk_assert( Qres > 0 ); cannam@154: cannam@154: /* Compute number of bits head room and normalize input */ cannam@154: b_headrm = silk_CLZ32( silk_abs(b32) ) - 1; cannam@154: b32_nrm = silk_LSHIFT(b32, b_headrm); /* Q: b_headrm */ cannam@154: cannam@154: /* Inverse of b32, with 14 bits of precision */ cannam@154: b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) ); /* Q: 29 + 16 - b_headrm */ cannam@154: cannam@154: /* First approximation */ cannam@154: result = silk_LSHIFT(b32_inv, 16); /* Q: 61 - b_headrm */ cannam@154: cannam@154: /* Compute residual by subtracting product of denominator and first approximation from one */ cannam@154: err_Q32 = silk_LSHIFT( ((opus_int32)1<<29) - silk_SMULWB(b32_nrm, b32_inv), 3 ); /* Q32 */ cannam@154: cannam@154: /* Refinement */ cannam@154: result = silk_SMLAWW(result, err_Q32, b32_inv); /* Q: 61 - b_headrm */ cannam@154: cannam@154: /* Convert to Qres domain */ cannam@154: lshift = 61 - b_headrm - Qres; cannam@154: if( lshift <= 0 ) { cannam@154: return silk_LSHIFT_SAT32(result, -lshift); cannam@154: } else { cannam@154: if( lshift < 32){ cannam@154: return silk_RSHIFT(result, lshift); cannam@154: }else{ cannam@154: /* Avoid undefined result */ cannam@154: return 0; cannam@154: } cannam@154: } cannam@154: } cannam@154: cannam@154: #ifdef __cplusplus cannam@154: } cannam@154: #endif cannam@154: cannam@154: #endif /* SILK_FIX_INLINES_H */