tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_q15.c

   1 /* ----------------------------------------------------------------------
   2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
   3 *
   4 * $Date:        17. January 2013
   5 * $Revision:    V1.4.1
   6 *
   7 * Project:          CMSIS DSP Library
   8 * Title:                arm_cmplx_conj_q15.c
   9 *
  10 * Description:  Q15 complex conjugate.
  11 *
  12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  13 *
  14 * Redistribution and use in source and binary forms, with or without
  15 * modification, are permitted provided that the following conditions
  16 * are met:
  17 *   - Redistributions of source code must retain the above copyright
  18 *     notice, this list of conditions and the following disclaimer.
  19 *   - Redistributions in binary form must reproduce the above copyright
  20 *     notice, this list of conditions and the following disclaimer in
  21 *     the documentation and/or other materials provided with the
  22 *     distribution.
  23 *   - Neither the name of ARM LIMITED nor the names of its contributors
  24 *     may be used to endorse or promote products derived from this
  25 *     software without specific prior written permission.
  26 *
  27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38 * POSSIBILITY OF SUCH DAMAGE.
  39 * ---------------------------------------------------------------------------- */
  40
  41 #include "arm_math.h"
  42
  43 /**
  44  * @ingroup groupCmplxMath
  45  */
  46
  47 /**
  48  * @addtogroup cmplx_conj
  49  * @{
  50  */
  51
  52 /**
  53  * @brief  Q15 complex conjugate.
  54  * @param  *pSrc points to the input vector
  55  * @param  *pDst points to the output vector
  56  * @param  numSamples number of complex samples in each vector
  57  * @return none.
  58  *
  59  * <b>Scaling and Overflow Behavior:</b>
  60  * \par
  61  * The function uses saturating arithmetic.
  62  * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
  63  */
  64
  65 void arm_cmplx_conj_q15(
  66   q15_t * pSrc,
  67   q15_t * pDst,
  68   uint32_t numSamples)
  69 {
  70
  71 #ifndef ARM_MATH_CM0_FAMILY
  72
  73   /* Run the below code for Cortex-M4 and Cortex-M3 */
  74   uint32_t blkCnt;                               /* loop counter */
  75   q31_t in1, in2, in3, in4;
  76   q31_t zero = 0;
  77
  78   /*loop Unrolling */
  79   blkCnt = numSamples >> 2u;
  80
  81   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  82    ** a second loop below computes the remaining 1 to 3 samples. */
  83   while(blkCnt > 0u)
  84   {
  85     /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
  86     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
  87     in1 = *__SIMD32(pSrc)++;
  88     in2 = *__SIMD32(pSrc)++;
  89     in3 = *__SIMD32(pSrc)++;
  90     in4 = *__SIMD32(pSrc)++;
  91
  92 #ifndef ARM_MATH_BIG_ENDIAN
  93
  94     in1 = __QASX(zero, in1);
  95     in2 = __QASX(zero, in2);
  96     in3 = __QASX(zero, in3);
  97     in4 = __QASX(zero, in4);
  98
  99 #else
 100
 101     in1 = __QSAX(zero, in1);
 102     in2 = __QSAX(zero, in2);
 103     in3 = __QSAX(zero, in3);
 104     in4 = __QSAX(zero, in4);
 105
 106 #endif //       #ifndef ARM_MATH_BIG_ENDIAN
 107
 108     in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16);
 109     in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16);
 110     in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16);
 111     in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16);
 112
 113     *__SIMD32(pDst)++ = in1;
 114     *__SIMD32(pDst)++ = in2;
 115     *__SIMD32(pDst)++ = in3;
 116     *__SIMD32(pDst)++ = in4;
 117
 118     /* Decrement the loop counter */
 119     blkCnt--;
 120   }
 121
 122   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 123    ** No loop unrolling is used. */
 124   blkCnt = numSamples % 0x4u;
 125
 126   while(blkCnt > 0u)
 127   {
 128     /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
 129     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
 130     *pDst++ = *pSrc++;
 131     *pDst++ = __SSAT(-*pSrc++, 16);
 132
 133     /* Decrement the loop counter */
 134     blkCnt--;
 135   }
 136
 137 #else
 138
 139   q15_t in;
 140
 141   /* Run the below code for Cortex-M0 */
 142
 143   while(numSamples > 0u)
 144   {
 145     /* realOut + j (imagOut) = realIn+ j (-1) imagIn */
 146     /* Calculate Complex Conjugate and then store the results in the destination buffer. */
 147     *pDst++ = *pSrc++;
 148     in = *pSrc++;
 149     *pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;
 150
 151     /* Decrement the loop counter */
 152     numSamples--;
 153   }
 154
 155 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 156
 157 }
 158
 159 /**
 160  * @} end of cmplx_conj group
 161  */