tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/SupportFunctions/arm_q7_to_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_q7_to_q15.c
   9 *
  10 * Description:  Converts the elements of the Q7 vector to Q15 vector.
  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 groupSupport
  45  */
  46
  47 /**
  48  * @addtogroup q7_to_x
  49  * @{
  50  */
  51
  52
  53
  54
  55 /**
  56  * @brief Converts the elements of the Q7 vector to Q15 vector.
  57  * @param[in]       *pSrc points to the Q7 input vector
  58  * @param[out]      *pDst points to the Q15 output vector
  59  * @param[in]       blockSize length of the input vector
  60  * @return none.
  61  *
  62  * \par Description:
  63  *
  64  * The equation used for the conversion process is:
  65  *
  66  * <pre>
  67  *      pDst[n] = (q15_t) pSrc[n] << 8;   0 <= n < blockSize.
  68  * </pre>
  69  *
  70  */
  71
  72
  73 void arm_q7_to_q15(
  74   q7_t * pSrc,
  75   q15_t * pDst,
  76   uint32_t blockSize)
  77 {
  78   q7_t *pIn = pSrc;                              /* Src pointer */
  79   uint32_t blkCnt;                               /* loop counter */
  80
  81 #ifndef ARM_MATH_CM0_FAMILY
  82   q31_t in;
  83   q31_t in1, in2;
  84   q31_t out1, out2;
  85
  86   /* Run the below code for Cortex-M4 and Cortex-M3 */
  87
  88   /*loop Unrolling */
  89   blkCnt = blockSize >> 2u;
  90
  91   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  92    ** a second loop below computes the remaining 1 to 3 samples. */
  93   while(blkCnt > 0u)
  94   {
  95     /* C = (q15_t) A << 8 */
  96     /* convert from q7 to q15 and then store the results in the destination buffer */
  97     in = *__SIMD32(pIn)++;
  98
  99     /* rotatate in by 8 and extend two q7_t values to q15_t values */
 100     in1 = __SXTB16(__ROR(in, 8));
 101
 102     /* extend remainig two q7_t values to q15_t values */
 103     in2 = __SXTB16(in);
 104
 105     in1 = in1 << 8u;
 106     in2 = in2 << 8u;
 107
 108     in1 = in1 & 0xFF00FF00;
 109     in2 = in2 & 0xFF00FF00;
 110
 111 #ifndef ARM_MATH_BIG_ENDIAN
 112
 113     out2 = __PKHTB(in1, in2, 16);
 114     out1 = __PKHBT(in2, in1, 16);
 115
 116 #else
 117
 118     out1 = __PKHTB(in1, in2, 16);
 119     out2 = __PKHBT(in2, in1, 16);
 120
 121 #endif
 122
 123     *__SIMD32(pDst)++ = out1;
 124     *__SIMD32(pDst)++ = out2;
 125
 126     /* Decrement the loop counter */
 127     blkCnt--;
 128   }
 129
 130   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
 131    ** No loop unrolling is used. */
 132   blkCnt = blockSize % 0x4u;
 133
 134 #else
 135
 136   /* Run the below code for Cortex-M0 */
 137
 138   /* Loop over blockSize number of values */
 139   blkCnt = blockSize;
 140
 141 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 142
 143   while(blkCnt > 0u)
 144   {
 145     /* C = (q15_t) A << 8 */
 146     /* convert from q7 to q15 and then store the results in the destination buffer */
 147     *pDst++ = (q15_t) * pIn++ << 8;
 148
 149     /* Decrement the loop counter */
 150     blkCnt--;
 151   }
 152
 153 }
 154
 155 /**
 156  * @} end of q7_to_x group
 157  */