Analog Devices / Mbed OS EVAL-CN0540-ARDZ

Dependencies:   platform_drivers LTC26X6 AD77681

CMSIS-DSP_Lib/Source/BasicMathFunctions/arm_shift_q31.c@1:9dd7c64b4a64, 2021-12-06 (annotated)

Committer:
jngarlitos
Date:
Mon Dec 06 05:22:28 2021 +0000
Revision:
1:9dd7c64b4a64
EVAL-CN0540-ARDZ mbed example program Initial Commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jngarlitos 1:9dd7c64b4a64 1 /* ----------------------------------------------------------------------
jngarlitos 1:9dd7c64b4a64 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
jngarlitos 1:9dd7c64b4a64 3 *
jngarlitos 1:9dd7c64b4a64 4 * $Date: 19. March 2015
jngarlitos 1:9dd7c64b4a64 5 * $Revision: V.1.4.5
jngarlitos 1:9dd7c64b4a64 6 *
jngarlitos 1:9dd7c64b4a64 7 * Project: CMSIS DSP Library
jngarlitos 1:9dd7c64b4a64 8 * Title: arm_shift_q31.c
jngarlitos 1:9dd7c64b4a64 9 *
jngarlitos 1:9dd7c64b4a64 10 * Description: Shifts the elements of a Q31 vector by a specified number of bits.
jngarlitos 1:9dd7c64b4a64 11 *
jngarlitos 1:9dd7c64b4a64 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
jngarlitos 1:9dd7c64b4a64 13 *
jngarlitos 1:9dd7c64b4a64 14 * Redistribution and use in source and binary forms, with or without
jngarlitos 1:9dd7c64b4a64 15 * modification, are permitted provided that the following conditions
jngarlitos 1:9dd7c64b4a64 16 * are met:
jngarlitos 1:9dd7c64b4a64 17 * - Redistributions of source code must retain the above copyright
jngarlitos 1:9dd7c64b4a64 18 * notice, this list of conditions and the following disclaimer.
jngarlitos 1:9dd7c64b4a64 19 * - Redistributions in binary form must reproduce the above copyright
jngarlitos 1:9dd7c64b4a64 20 * notice, this list of conditions and the following disclaimer in
jngarlitos 1:9dd7c64b4a64 21 * the documentation and/or other materials provided with the
jngarlitos 1:9dd7c64b4a64 22 * distribution.
jngarlitos 1:9dd7c64b4a64 23 * - Neither the name of ARM LIMITED nor the names of its contributors
jngarlitos 1:9dd7c64b4a64 24 * may be used to endorse or promote products derived from this
jngarlitos 1:9dd7c64b4a64 25 * software without specific prior written permission.
jngarlitos 1:9dd7c64b4a64 26 *
jngarlitos 1:9dd7c64b4a64 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
jngarlitos 1:9dd7c64b4a64 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
jngarlitos 1:9dd7c64b4a64 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
jngarlitos 1:9dd7c64b4a64 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
jngarlitos 1:9dd7c64b4a64 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
jngarlitos 1:9dd7c64b4a64 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
jngarlitos 1:9dd7c64b4a64 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
jngarlitos 1:9dd7c64b4a64 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
jngarlitos 1:9dd7c64b4a64 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
jngarlitos 1:9dd7c64b4a64 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
jngarlitos 1:9dd7c64b4a64 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
jngarlitos 1:9dd7c64b4a64 38 * POSSIBILITY OF SUCH DAMAGE.
jngarlitos 1:9dd7c64b4a64 39 * -------------------------------------------------------------------- */
jngarlitos 1:9dd7c64b4a64 40
jngarlitos 1:9dd7c64b4a64 41 #include "arm_math.h"
jngarlitos 1:9dd7c64b4a64 42
jngarlitos 1:9dd7c64b4a64 43 /**
jngarlitos 1:9dd7c64b4a64 44 * @ingroup groupMath
jngarlitos 1:9dd7c64b4a64 45 */
jngarlitos 1:9dd7c64b4a64 46 /**
jngarlitos 1:9dd7c64b4a64 47 * @defgroup shift Vector Shift
jngarlitos 1:9dd7c64b4a64 48 *
jngarlitos 1:9dd7c64b4a64 49 * Shifts the elements of a fixed-point vector by a specified number of bits.
jngarlitos 1:9dd7c64b4a64 50 * There are separate functions for Q7, Q15, and Q31 data types.
jngarlitos 1:9dd7c64b4a64 51 * The underlying algorithm used is:
jngarlitos 1:9dd7c64b4a64 52 *
jngarlitos 1:9dd7c64b4a64 53 * <pre>
jngarlitos 1:9dd7c64b4a64 54 * pDst[n] = pSrc[n] << shift, 0 <= n < blockSize.
jngarlitos 1:9dd7c64b4a64 55 * </pre>
jngarlitos 1:9dd7c64b4a64 56 *
jngarlitos 1:9dd7c64b4a64 57 * If <code>shift</code> is positive then the elements of the vector are shifted to the left.
jngarlitos 1:9dd7c64b4a64 58 * If <code>shift</code> is negative then the elements of the vector are shifted to the right.
jngarlitos 1:9dd7c64b4a64 59 *
jngarlitos 1:9dd7c64b4a64 60 * The functions support in-place computation allowing the source and destination
jngarlitos 1:9dd7c64b4a64 61 * pointers to reference the same memory buffer.
jngarlitos 1:9dd7c64b4a64 62 */
jngarlitos 1:9dd7c64b4a64 63
jngarlitos 1:9dd7c64b4a64 64 /**
jngarlitos 1:9dd7c64b4a64 65 * @addtogroup shift
jngarlitos 1:9dd7c64b4a64 66 * @{
jngarlitos 1:9dd7c64b4a64 67 */
jngarlitos 1:9dd7c64b4a64 68
jngarlitos 1:9dd7c64b4a64 69 /**
jngarlitos 1:9dd7c64b4a64 70 * @brief Shifts the elements of a Q31 vector a specified number of bits.
jngarlitos 1:9dd7c64b4a64 71 * @param[in] *pSrc points to the input vector
jngarlitos 1:9dd7c64b4a64 72 * @param[in] shiftBits number of bits to shift. A positive value shifts left; a negative value shifts right.
jngarlitos 1:9dd7c64b4a64 73 * @param[out] *pDst points to the output vector
jngarlitos 1:9dd7c64b4a64 74 * @param[in] blockSize number of samples in the vector
jngarlitos 1:9dd7c64b4a64 75 * @return none.
jngarlitos 1:9dd7c64b4a64 76 *
jngarlitos 1:9dd7c64b4a64 77 *
jngarlitos 1:9dd7c64b4a64 78 * <b>Scaling and Overflow Behavior:</b>
jngarlitos 1:9dd7c64b4a64 79 * \par
jngarlitos 1:9dd7c64b4a64 80 * The function uses saturating arithmetic.
jngarlitos 1:9dd7c64b4a64 81 * Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] will be saturated.
jngarlitos 1:9dd7c64b4a64 82 */
jngarlitos 1:9dd7c64b4a64 83
jngarlitos 1:9dd7c64b4a64 84 void arm_shift_q31(
jngarlitos 1:9dd7c64b4a64 85 q31_t * pSrc,
jngarlitos 1:9dd7c64b4a64 86 int8_t shiftBits,
jngarlitos 1:9dd7c64b4a64 87 q31_t * pDst,
jngarlitos 1:9dd7c64b4a64 88 uint32_t blockSize)
jngarlitos 1:9dd7c64b4a64 89 {
jngarlitos 1:9dd7c64b4a64 90 uint32_t blkCnt; /* loop counter */
jngarlitos 1:9dd7c64b4a64 91 uint8_t sign = (shiftBits & 0x80); /* Sign of shiftBits */
jngarlitos 1:9dd7c64b4a64 92
jngarlitos 1:9dd7c64b4a64 93 #ifndef ARM_MATH_CM0_FAMILY
jngarlitos 1:9dd7c64b4a64 94
jngarlitos 1:9dd7c64b4a64 95 q31_t in1, in2, in3, in4; /* Temporary input variables */
jngarlitos 1:9dd7c64b4a64 96 q31_t out1, out2, out3, out4; /* Temporary output variables */
jngarlitos 1:9dd7c64b4a64 97
jngarlitos 1:9dd7c64b4a64 98 /*loop Unrolling */
jngarlitos 1:9dd7c64b4a64 99 blkCnt = blockSize >> 2u;
jngarlitos 1:9dd7c64b4a64 100
jngarlitos 1:9dd7c64b4a64 101
jngarlitos 1:9dd7c64b4a64 102 if(sign == 0u)
jngarlitos 1:9dd7c64b4a64 103 {
jngarlitos 1:9dd7c64b4a64 104 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
jngarlitos 1:9dd7c64b4a64 105 ** a second loop below computes the remaining 1 to 3 samples. */
jngarlitos 1:9dd7c64b4a64 106 while(blkCnt > 0u)
jngarlitos 1:9dd7c64b4a64 107 {
jngarlitos 1:9dd7c64b4a64 108 /* C = A << shiftBits */
jngarlitos 1:9dd7c64b4a64 109 /* Shift the input and then store the results in the destination buffer. */
jngarlitos 1:9dd7c64b4a64 110 in1 = *pSrc;
jngarlitos 1:9dd7c64b4a64 111 in2 = *(pSrc + 1);
jngarlitos 1:9dd7c64b4a64 112 out1 = in1 << shiftBits;
jngarlitos 1:9dd7c64b4a64 113 in3 = *(pSrc + 2);
jngarlitos 1:9dd7c64b4a64 114 out2 = in2 << shiftBits;
jngarlitos 1:9dd7c64b4a64 115 in4 = *(pSrc + 3);
jngarlitos 1:9dd7c64b4a64 116 if(in1 != (out1 >> shiftBits))
jngarlitos 1:9dd7c64b4a64 117 out1 = 0x7FFFFFFF ^ (in1 >> 31);
jngarlitos 1:9dd7c64b4a64 118
jngarlitos 1:9dd7c64b4a64 119 if(in2 != (out2 >> shiftBits))
jngarlitos 1:9dd7c64b4a64 120 out2 = 0x7FFFFFFF ^ (in2 >> 31);
jngarlitos 1:9dd7c64b4a64 121
jngarlitos 1:9dd7c64b4a64 122 *pDst = out1;
jngarlitos 1:9dd7c64b4a64 123 out3 = in3 << shiftBits;
jngarlitos 1:9dd7c64b4a64 124 *(pDst + 1) = out2;
jngarlitos 1:9dd7c64b4a64 125 out4 = in4 << shiftBits;
jngarlitos 1:9dd7c64b4a64 126
jngarlitos 1:9dd7c64b4a64 127 if(in3 != (out3 >> shiftBits))
jngarlitos 1:9dd7c64b4a64 128 out3 = 0x7FFFFFFF ^ (in3 >> 31);
jngarlitos 1:9dd7c64b4a64 129
jngarlitos 1:9dd7c64b4a64 130 if(in4 != (out4 >> shiftBits))
jngarlitos 1:9dd7c64b4a64 131 out4 = 0x7FFFFFFF ^ (in4 >> 31);
jngarlitos 1:9dd7c64b4a64 132
jngarlitos 1:9dd7c64b4a64 133 *(pDst + 2) = out3;
jngarlitos 1:9dd7c64b4a64 134 *(pDst + 3) = out4;
jngarlitos 1:9dd7c64b4a64 135
jngarlitos 1:9dd7c64b4a64 136 /* Update destination pointer to process next sampels */
jngarlitos 1:9dd7c64b4a64 137 pSrc += 4u;
jngarlitos 1:9dd7c64b4a64 138 pDst += 4u;
jngarlitos 1:9dd7c64b4a64 139
jngarlitos 1:9dd7c64b4a64 140 /* Decrement the loop counter */
jngarlitos 1:9dd7c64b4a64 141 blkCnt--;
jngarlitos 1:9dd7c64b4a64 142 }
jngarlitos 1:9dd7c64b4a64 143 }
jngarlitos 1:9dd7c64b4a64 144 else
jngarlitos 1:9dd7c64b4a64 145 {
jngarlitos 1:9dd7c64b4a64 146
jngarlitos 1:9dd7c64b4a64 147 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
jngarlitos 1:9dd7c64b4a64 148 ** a second loop below computes the remaining 1 to 3 samples. */
jngarlitos 1:9dd7c64b4a64 149 while(blkCnt > 0u)
jngarlitos 1:9dd7c64b4a64 150 {
jngarlitos 1:9dd7c64b4a64 151 /* C = A >> shiftBits */
jngarlitos 1:9dd7c64b4a64 152 /* Shift the input and then store the results in the destination buffer. */
jngarlitos 1:9dd7c64b4a64 153 in1 = *pSrc;
jngarlitos 1:9dd7c64b4a64 154 in2 = *(pSrc + 1);
jngarlitos 1:9dd7c64b4a64 155 in3 = *(pSrc + 2);
jngarlitos 1:9dd7c64b4a64 156 in4 = *(pSrc + 3);
jngarlitos 1:9dd7c64b4a64 157
jngarlitos 1:9dd7c64b4a64 158 *pDst = (in1 >> -shiftBits);
jngarlitos 1:9dd7c64b4a64 159 *(pDst + 1) = (in2 >> -shiftBits);
jngarlitos 1:9dd7c64b4a64 160 *(pDst + 2) = (in3 >> -shiftBits);
jngarlitos 1:9dd7c64b4a64 161 *(pDst + 3) = (in4 >> -shiftBits);
jngarlitos 1:9dd7c64b4a64 162
jngarlitos 1:9dd7c64b4a64 163
jngarlitos 1:9dd7c64b4a64 164 pSrc += 4u;
jngarlitos 1:9dd7c64b4a64 165 pDst += 4u;
jngarlitos 1:9dd7c64b4a64 166
jngarlitos 1:9dd7c64b4a64 167 blkCnt--;
jngarlitos 1:9dd7c64b4a64 168 }
jngarlitos 1:9dd7c64b4a64 169
jngarlitos 1:9dd7c64b4a64 170 }
jngarlitos 1:9dd7c64b4a64 171
jngarlitos 1:9dd7c64b4a64 172 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
jngarlitos 1:9dd7c64b4a64 173 ** No loop unrolling is used. */
jngarlitos 1:9dd7c64b4a64 174 blkCnt = blockSize % 0x4u;
jngarlitos 1:9dd7c64b4a64 175
jngarlitos 1:9dd7c64b4a64 176 #else
jngarlitos 1:9dd7c64b4a64 177
jngarlitos 1:9dd7c64b4a64 178 /* Run the below code for Cortex-M0 */
jngarlitos 1:9dd7c64b4a64 179
jngarlitos 1:9dd7c64b4a64 180
jngarlitos 1:9dd7c64b4a64 181 /* Initialize blkCnt with number of samples */
jngarlitos 1:9dd7c64b4a64 182 blkCnt = blockSize;
jngarlitos 1:9dd7c64b4a64 183
jngarlitos 1:9dd7c64b4a64 184 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
jngarlitos 1:9dd7c64b4a64 185
jngarlitos 1:9dd7c64b4a64 186
jngarlitos 1:9dd7c64b4a64 187 while(blkCnt > 0u)
jngarlitos 1:9dd7c64b4a64 188 {
jngarlitos 1:9dd7c64b4a64 189 /* C = A (>> or <<) shiftBits */
jngarlitos 1:9dd7c64b4a64 190 /* Shift the input and then store the result in the destination buffer. */
jngarlitos 1:9dd7c64b4a64 191 *pDst++ = (sign == 0u) ? clip_q63_to_q31((q63_t) * pSrc++ << shiftBits) :
jngarlitos 1:9dd7c64b4a64 192 (*pSrc++ >> -shiftBits);
jngarlitos 1:9dd7c64b4a64 193
jngarlitos 1:9dd7c64b4a64 194 /* Decrement the loop counter */
jngarlitos 1:9dd7c64b4a64 195 blkCnt--;
jngarlitos 1:9dd7c64b4a64 196 }
jngarlitos 1:9dd7c64b4a64 197
jngarlitos 1:9dd7c64b4a64 198
jngarlitos 1:9dd7c64b4a64 199 }
jngarlitos 1:9dd7c64b4a64 200
jngarlitos 1:9dd7c64b4a64 201 /**
jngarlitos 1:9dd7c64b4a64 202 * @} end of shift group
jngarlitos 1:9dd7c64b4a64 203 */