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CMSIS DSP library

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cmsis_dsp/SupportFunctions/arm_float_to_q31.c@4:9cee975aadce, 2014-06-23 (annotated)

Committer:
mbed_official
Date:
Mon Jun 23 09:30:09 2014 +0100
Revision:
4:9cee975aadce
Parent:
3:7a284390b0ce
Child:
5:3762170b6d4d
Synchronized with git revision 6e7c7bcec41226f536474daae3c13d49e4c0e865



Full URL: https://github.com/mbedmicro/mbed/commit/6e7c7bcec41226f536474daae3c13d49e4c0e865/



Fix signed unsigned compare in dsp library

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_float_to_q31.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Converts the elements of the floating-point vector to Q31 vector.
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 groupSupport
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @defgroup float_to_x Convert 32-bit floating point value
emilmont 1:fdd22bb7aa52 49 */
emilmont 1:fdd22bb7aa52 50
emilmont 1:fdd22bb7aa52 51 /**
emilmont 1:fdd22bb7aa52 52 * @addtogroup float_to_x
emilmont 1:fdd22bb7aa52 53 * @{
emilmont 1:fdd22bb7aa52 54 */
emilmont 1:fdd22bb7aa52 55
emilmont 1:fdd22bb7aa52 56 /**
emilmont 1:fdd22bb7aa52 57 * @brief Converts the elements of the floating-point vector to Q31 vector.
emilmont 1:fdd22bb7aa52 58 * @param[in] *pSrc points to the floating-point input vector
emilmont 1:fdd22bb7aa52 59 * @param[out] *pDst points to the Q31 output vector
emilmont 1:fdd22bb7aa52 60 * @param[in] blockSize length of the input vector
emilmont 1:fdd22bb7aa52 61 * @return none.
emilmont 1:fdd22bb7aa52 62 *
emilmont 1:fdd22bb7aa52 63 *\par Description:
emilmont 1:fdd22bb7aa52 64 * \par
emilmont 1:fdd22bb7aa52 65 * The equation used for the conversion process is:
emilmont 1:fdd22bb7aa52 66 *
emilmont 1:fdd22bb7aa52 67 * <pre>
emilmont 2:da51fb522205 68 * pDst[n] = (q31_t)(pSrc[n] * 2147483648); 0 <= n < blockSize.
emilmont 1:fdd22bb7aa52 69 * </pre>
emilmont 1:fdd22bb7aa52 70 * <b>Scaling and Overflow Behavior:</b>
emilmont 1:fdd22bb7aa52 71 * \par
emilmont 1:fdd22bb7aa52 72 * The function uses saturating arithmetic.
emilmont 1:fdd22bb7aa52 73 * Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated.
emilmont 1:fdd22bb7aa52 74 *
emilmont 1:fdd22bb7aa52 75 * \note In order to apply rounding, the library should be rebuilt with the ROUNDING macro
emilmont 1:fdd22bb7aa52 76 * defined in the preprocessor section of project options.
emilmont 1:fdd22bb7aa52 77 */
emilmont 1:fdd22bb7aa52 78
emilmont 1:fdd22bb7aa52 79
emilmont 1:fdd22bb7aa52 80 void arm_float_to_q31(
emilmont 1:fdd22bb7aa52 81 float32_t * pSrc,
emilmont 1:fdd22bb7aa52 82 q31_t * pDst,
emilmont 1:fdd22bb7aa52 83 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 84 {
emilmont 1:fdd22bb7aa52 85 float32_t *pIn = pSrc; /* Src pointer */
emilmont 1:fdd22bb7aa52 86 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 87
emilmont 1:fdd22bb7aa52 88 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 89
emilmont 1:fdd22bb7aa52 90 float32_t in;
emilmont 1:fdd22bb7aa52 91
emilmont 1:fdd22bb7aa52 92 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 93
mbed_official 3:7a284390b0ce 94 #ifndef ARM_MATH_CM0_FAMILY
emilmont 1:fdd22bb7aa52 95
emilmont 1:fdd22bb7aa52 96 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 97
emilmont 1:fdd22bb7aa52 98 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 99 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 102 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 103 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 104 {
emilmont 1:fdd22bb7aa52 105
emilmont 1:fdd22bb7aa52 106 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 107
emilmont 1:fdd22bb7aa52 108 /* C = A * 32768 */
emilmont 1:fdd22bb7aa52 109 /* convert from float to Q31 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 110 in = *pIn++;
emilmont 1:fdd22bb7aa52 111 in = (in * 2147483648.0f);
emilmont 1:fdd22bb7aa52 112 in += in > 0 ? 0.5 : -0.5;
emilmont 1:fdd22bb7aa52 113 *pDst++ = clip_q63_to_q31((q63_t) (in));
emilmont 1:fdd22bb7aa52 114
emilmont 1:fdd22bb7aa52 115 in = *pIn++;
emilmont 1:fdd22bb7aa52 116 in = (in * 2147483648.0f);
emilmont 1:fdd22bb7aa52 117 in += in > 0 ? 0.5 : -0.5;
emilmont 1:fdd22bb7aa52 118 *pDst++ = clip_q63_to_q31((q63_t) (in));
emilmont 1:fdd22bb7aa52 119
emilmont 1:fdd22bb7aa52 120 in = *pIn++;
emilmont 1:fdd22bb7aa52 121 in = (in * 2147483648.0f);
emilmont 1:fdd22bb7aa52 122 in += in > 0 ? 0.5 : -0.5;
emilmont 1:fdd22bb7aa52 123 *pDst++ = clip_q63_to_q31((q63_t) (in));
emilmont 1:fdd22bb7aa52 124
emilmont 1:fdd22bb7aa52 125 in = *pIn++;
emilmont 1:fdd22bb7aa52 126 in = (in * 2147483648.0f);
emilmont 1:fdd22bb7aa52 127 in += in > 0 ? 0.5 : -0.5;
emilmont 1:fdd22bb7aa52 128 *pDst++ = clip_q63_to_q31((q63_t) (in));
emilmont 1:fdd22bb7aa52 129
emilmont 1:fdd22bb7aa52 130 #else
emilmont 1:fdd22bb7aa52 131
emilmont 1:fdd22bb7aa52 132 /* C = A * 2147483648 */
emilmont 1:fdd22bb7aa52 133 /* convert from float to Q31 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 134 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
emilmont 1:fdd22bb7aa52 135 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
emilmont 1:fdd22bb7aa52 136 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
emilmont 1:fdd22bb7aa52 137 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
emilmont 1:fdd22bb7aa52 138
emilmont 1:fdd22bb7aa52 139 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 140
emilmont 1:fdd22bb7aa52 141 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 142 blkCnt--;
emilmont 1:fdd22bb7aa52 143 }
emilmont 1:fdd22bb7aa52 144
emilmont 1:fdd22bb7aa52 145 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 146 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 147 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 148
emilmont 1:fdd22bb7aa52 149 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 150 {
emilmont 1:fdd22bb7aa52 151
emilmont 1:fdd22bb7aa52 152 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 153
emilmont 1:fdd22bb7aa52 154 /* C = A * 2147483648 */
emilmont 1:fdd22bb7aa52 155 /* convert from float to Q31 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 156 in = *pIn++;
emilmont 1:fdd22bb7aa52 157 in = (in * 2147483648.0f);
emilmont 1:fdd22bb7aa52 158 in += in > 0 ? 0.5 : -0.5;
emilmont 1:fdd22bb7aa52 159 *pDst++ = clip_q63_to_q31((q63_t) (in));
emilmont 1:fdd22bb7aa52 160
emilmont 1:fdd22bb7aa52 161 #else
emilmont 1:fdd22bb7aa52 162
emilmont 1:fdd22bb7aa52 163 /* C = A * 2147483648 */
emilmont 1:fdd22bb7aa52 164 /* convert from float to Q31 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 165 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
emilmont 1:fdd22bb7aa52 166
emilmont 1:fdd22bb7aa52 167 #endif /* #ifdef ARM_MATH_ROUNDING */
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
emilmont 1:fdd22bb7aa52 173
emilmont 1:fdd22bb7aa52 174 #else
emilmont 1:fdd22bb7aa52 175
emilmont 1:fdd22bb7aa52 176 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 177
emilmont 1:fdd22bb7aa52 178 /* Loop over blockSize number of values */
emilmont 1:fdd22bb7aa52 179 blkCnt = blockSize;
emilmont 1:fdd22bb7aa52 180
emilmont 1:fdd22bb7aa52 181 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 182 {
emilmont 1:fdd22bb7aa52 183
emilmont 1:fdd22bb7aa52 184 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 185
emilmont 1:fdd22bb7aa52 186 /* C = A * 2147483648 */
emilmont 1:fdd22bb7aa52 187 /* convert from float to Q31 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 188 in = *pIn++;
emilmont 1:fdd22bb7aa52 189 in = (in * 2147483648.0f);
emilmont 1:fdd22bb7aa52 190 in += in > 0 ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 191 *pDst++ = clip_q63_to_q31((q63_t) (in));
emilmont 1:fdd22bb7aa52 192
emilmont 1:fdd22bb7aa52 193 #else
emilmont 1:fdd22bb7aa52 194
emilmont 1:fdd22bb7aa52 195 /* C = A * 2147483648 */
emilmont 1:fdd22bb7aa52 196 /* convert from float to Q31 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 197 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
emilmont 1:fdd22bb7aa52 198
emilmont 1:fdd22bb7aa52 199 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 200
emilmont 1:fdd22bb7aa52 201 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 202 blkCnt--;
emilmont 1:fdd22bb7aa52 203 }
emilmont 1:fdd22bb7aa52 204
mbed_official 3:7a284390b0ce 205 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emilmont 1:fdd22bb7aa52 206
emilmont 1:fdd22bb7aa52 207 }
emilmont 1:fdd22bb7aa52 208
emilmont 1:fdd22bb7aa52 209 /**
emilmont 1:fdd22bb7aa52 210 * @} end of float_to_x group
emilmont 1:fdd22bb7aa52 211 */