Michele Riccio / mbed-dsp_F767ZI

mbed-os 6.10 versione

cmsis_dsp/BasicMathFunctions/arm_abs_q15.c@3:7a284390b0ce, 2013-11-08 (annotated)

Committer:
mbed_official
Date:
Fri Nov 08 13:45:10 2013 +0000
Revision:
3:7a284390b0ce
Parent:
2:da51fb522205 
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
mbed_official 3:7a284390b0ce 2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 3:7a284390b0ce 4 * $Date: 17. January 2013
mbed_official 3:7a284390b0ce 5 * $Revision: V1.4.1
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 2:da51fb522205 8 * Title: arm_abs_q15.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Q15 vector absolute value.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
mbed_official 3:7a284390b0ce 14 * Redistribution and use in source and binary forms, with or without
mbed_official 3:7a284390b0ce 15 * modification, are permitted provided that the following conditions
mbed_official 3:7a284390b0ce 16 * are met:
mbed_official 3:7a284390b0ce 17 * - Redistributions of source code must retain the above copyright
mbed_official 3:7a284390b0ce 18 * notice, this list of conditions and the following disclaimer.
mbed_official 3:7a284390b0ce 19 * - Redistributions in binary form must reproduce the above copyright
mbed_official 3:7a284390b0ce 20 * notice, this list of conditions and the following disclaimer in
mbed_official 3:7a284390b0ce 21 * the documentation and/or other materials provided with the
mbed_official 3:7a284390b0ce 22 * distribution.
mbed_official 3:7a284390b0ce 23 * - Neither the name of ARM LIMITED nor the names of its contributors
mbed_official 3:7a284390b0ce 24 * may be used to endorse or promote products derived from this
mbed_official 3:7a284390b0ce 25 * software without specific prior written permission.
mbed_official 3:7a284390b0ce 26 *
mbed_official 3:7a284390b0ce 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
mbed_official 3:7a284390b0ce 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
mbed_official 3:7a284390b0ce 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
mbed_official 3:7a284390b0ce 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
mbed_official 3:7a284390b0ce 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
mbed_official 3:7a284390b0ce 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
mbed_official 3:7a284390b0ce 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
mbed_official 3:7a284390b0ce 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 3:7a284390b0ce 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
mbed_official 3:7a284390b0ce 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
mbed_official 3:7a284390b0ce 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
mbed_official 3:7a284390b0ce 38 * POSSIBILITY OF SUCH DAMAGE.
emilmont 1:fdd22bb7aa52 39 * -------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 40
emilmont 1:fdd22bb7aa52 41 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 42
emilmont 1:fdd22bb7aa52 43 /**
emilmont 1:fdd22bb7aa52 44 * @ingroup groupMath
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @addtogroup BasicAbs
emilmont 1:fdd22bb7aa52 49 * @{
emilmont 1:fdd22bb7aa52 50 */
emilmont 1:fdd22bb7aa52 51
emilmont 1:fdd22bb7aa52 52 /**
emilmont 1:fdd22bb7aa52 53 * @brief Q15 vector absolute value.
emilmont 1:fdd22bb7aa52 54 * @param[in] *pSrc points to the input buffer
emilmont 1:fdd22bb7aa52 55 * @param[out] *pDst points to the output buffer
emilmont 1:fdd22bb7aa52 56 * @param[in] blockSize number of samples in each vector
emilmont 1:fdd22bb7aa52 57 * @return none.
emilmont 1:fdd22bb7aa52 58 *
emilmont 1:fdd22bb7aa52 59 * <b>Scaling and Overflow Behavior:</b>
emilmont 1:fdd22bb7aa52 60 * \par
emilmont 1:fdd22bb7aa52 61 * The function uses saturating arithmetic.
emilmont 1:fdd22bb7aa52 62 * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
emilmont 1:fdd22bb7aa52 63 */
emilmont 1:fdd22bb7aa52 64
emilmont 1:fdd22bb7aa52 65 void arm_abs_q15(
emilmont 1:fdd22bb7aa52 66 q15_t * pSrc,
emilmont 1:fdd22bb7aa52 67 q15_t * pDst,
emilmont 1:fdd22bb7aa52 68 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 69 {
emilmont 1:fdd22bb7aa52 70 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 71
mbed_official 3:7a284390b0ce 72 #ifndef ARM_MATH_CM0_FAMILY
mbed_official 3:7a284390b0ce 73 __SIMD32_TYPE *simd;
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 76
emilmont 1:fdd22bb7aa52 77 q15_t in1; /* Input value1 */
emilmont 1:fdd22bb7aa52 78 q15_t in2; /* Input value2 */
emilmont 1:fdd22bb7aa52 79
emilmont 1:fdd22bb7aa52 80
emilmont 1:fdd22bb7aa52 81 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 82 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 83
emilmont 1:fdd22bb7aa52 84 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 85 ** a second loop below computes the remaining 1 to 3 samples. */
mbed_official 3:7a284390b0ce 86 simd = __SIMD32_CONST(pDst);
emilmont 1:fdd22bb7aa52 87 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 88 {
emilmont 1:fdd22bb7aa52 89 /* C = |A| */
emilmont 1:fdd22bb7aa52 90 /* Read two inputs */
emilmont 1:fdd22bb7aa52 91 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 92 in2 = *pSrc++;
emilmont 1:fdd22bb7aa52 93
emilmont 1:fdd22bb7aa52 94
emilmont 1:fdd22bb7aa52 95 /* Store the Absolute result in the destination buffer by packing the two values, in a single cycle */
emilmont 1:fdd22bb7aa52 96 #ifndef ARM_MATH_BIG_ENDIAN
mbed_official 3:7a284390b0ce 97 *simd++ =
mbed_official 3:7a284390b0ce 98 __PKHBT(((in1 > 0) ? in1 : (q15_t)__QSUB16(0, in1)),
mbed_official 3:7a284390b0ce 99 ((in2 > 0) ? in2 : (q15_t)__QSUB16(0, in2)), 16);
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101 #else
emilmont 1:fdd22bb7aa52 102
emilmont 1:fdd22bb7aa52 103
mbed_official 3:7a284390b0ce 104 *simd++ =
mbed_official 3:7a284390b0ce 105 __PKHBT(((in2 > 0) ? in2 : (q15_t)__QSUB16(0, in2)),
mbed_official 3:7a284390b0ce 106 ((in1 > 0) ? in1 : (q15_t)__QSUB16(0, in1)), 16);
emilmont 1:fdd22bb7aa52 107
emilmont 1:fdd22bb7aa52 108 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
emilmont 1:fdd22bb7aa52 109
emilmont 1:fdd22bb7aa52 110 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 111 in2 = *pSrc++;
emilmont 1:fdd22bb7aa52 112
emilmont 1:fdd22bb7aa52 113
emilmont 1:fdd22bb7aa52 114 #ifndef ARM_MATH_BIG_ENDIAN
emilmont 1:fdd22bb7aa52 115
mbed_official 3:7a284390b0ce 116 *simd++ =
mbed_official 3:7a284390b0ce 117 __PKHBT(((in1 > 0) ? in1 : (q15_t)__QSUB16(0, in1)),
mbed_official 3:7a284390b0ce 118 ((in2 > 0) ? in2 : (q15_t)__QSUB16(0, in2)), 16);
emilmont 1:fdd22bb7aa52 119
emilmont 1:fdd22bb7aa52 120 #else
emilmont 1:fdd22bb7aa52 121
emilmont 1:fdd22bb7aa52 122
mbed_official 3:7a284390b0ce 123 *simd++ =
mbed_official 3:7a284390b0ce 124 __PKHBT(((in2 > 0) ? in2 : (q15_t)__QSUB16(0, in2)),
mbed_official 3:7a284390b0ce 125 ((in1 > 0) ? in1 : (q15_t)__QSUB16(0, in1)), 16);
emilmont 1:fdd22bb7aa52 126
emilmont 1:fdd22bb7aa52 127 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
emilmont 1:fdd22bb7aa52 128
emilmont 1:fdd22bb7aa52 129 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 130 blkCnt--;
emilmont 1:fdd22bb7aa52 131 }
mbed_official 3:7a284390b0ce 132 pDst = (q15_t *)simd;
mbed_official 3:7a284390b0ce 133
emilmont 1:fdd22bb7aa52 134 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 135 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 136 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 137
emilmont 1:fdd22bb7aa52 138 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 139 {
emilmont 1:fdd22bb7aa52 140 /* C = |A| */
emilmont 1:fdd22bb7aa52 141 /* Read the input */
emilmont 1:fdd22bb7aa52 142 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 143
emilmont 1:fdd22bb7aa52 144 /* Calculate absolute value of input and then store the result in the destination buffer. */
mbed_official 3:7a284390b0ce 145 *pDst++ = (in1 > 0) ? in1 : (q15_t)__QSUB16(0, in1);
emilmont 1:fdd22bb7aa52 146
emilmont 1:fdd22bb7aa52 147 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 148 blkCnt--;
emilmont 1:fdd22bb7aa52 149 }
emilmont 1:fdd22bb7aa52 150
emilmont 1:fdd22bb7aa52 151 #else
emilmont 1:fdd22bb7aa52 152
emilmont 1:fdd22bb7aa52 153 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 154
emilmont 1:fdd22bb7aa52 155 q15_t in; /* Temporary input variable */
emilmont 1:fdd22bb7aa52 156
emilmont 1:fdd22bb7aa52 157 /* Initialize blkCnt with number of samples */
emilmont 1:fdd22bb7aa52 158 blkCnt = blockSize;
emilmont 1:fdd22bb7aa52 159
emilmont 1:fdd22bb7aa52 160 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 161 {
emilmont 1:fdd22bb7aa52 162 /* C = |A| */
emilmont 1:fdd22bb7aa52 163 /* Read the input */
emilmont 1:fdd22bb7aa52 164 in = *pSrc++;
emilmont 1:fdd22bb7aa52 165
emilmont 1:fdd22bb7aa52 166 /* Calculate absolute value of input and then store the result in the destination buffer. */
emilmont 1:fdd22bb7aa52 167 *pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
emilmont 1:fdd22bb7aa52 168
emilmont 1:fdd22bb7aa52 169 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 170 blkCnt--;
emilmont 1:fdd22bb7aa52 171 }
emilmont 1:fdd22bb7aa52 172
mbed_official 3:7a284390b0ce 173 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emilmont 1:fdd22bb7aa52 174
emilmont 1:fdd22bb7aa52 175 }
emilmont 1:fdd22bb7aa52 176
emilmont 1:fdd22bb7aa52 177 /**
emilmont 1:fdd22bb7aa52 178 * @} end of BasicAbs group
emilmont 1:fdd22bb7aa52 179 */