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CMSIS DSP library

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cmsis_dsp/SupportFunctions/arm_float_to_q7.c@5:3762170b6d4d, 2015-11-20 (annotated)

Committer:
mbed_official
Date:
Fri Nov 20 08:45:18 2015 +0000
Revision:
5:3762170b6d4d
Parent:
3:7a284390b0ce 
Synchronized with git revision 2eb940b9a73af188d3004a2575fdfbb05febe62b



Full URL: https://github.com/mbedmicro/mbed/commit/2eb940b9a73af188d3004a2575fdfbb05febe62b/



Added option to build rpc library. closes #1426

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------------
mbed_official 5:3762170b6d4d 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 5:3762170b6d4d 4 * $Date: 19. March 2015
mbed_official 5:3762170b6d4d 5 * $Revision: V.1.4.5
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 2:da51fb522205 8 * Title: arm_float_to_q7.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Converts the elements of the floating-point vector to Q7 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 * @addtogroup float_to_x
emilmont 1:fdd22bb7aa52 49 * @{
emilmont 1:fdd22bb7aa52 50 */
emilmont 1:fdd22bb7aa52 51
emilmont 1:fdd22bb7aa52 52 /**
emilmont 1:fdd22bb7aa52 53 * @brief Converts the elements of the floating-point vector to Q7 vector.
emilmont 1:fdd22bb7aa52 54 * @param[in] *pSrc points to the floating-point input vector
emilmont 1:fdd22bb7aa52 55 * @param[out] *pDst points to the Q7 output vector
emilmont 1:fdd22bb7aa52 56 * @param[in] blockSize length of the input vector
emilmont 1:fdd22bb7aa52 57 * @return none.
emilmont 1:fdd22bb7aa52 58 *
emilmont 1:fdd22bb7aa52 59 *\par Description:
emilmont 1:fdd22bb7aa52 60 * \par
emilmont 1:fdd22bb7aa52 61 * The equation used for the conversion process is:
emilmont 1:fdd22bb7aa52 62 * <pre>
emilmont 2:da51fb522205 63 * pDst[n] = (q7_t)(pSrc[n] * 128); 0 <= n < blockSize.
emilmont 1:fdd22bb7aa52 64 * </pre>
emilmont 1:fdd22bb7aa52 65 * \par Scaling and Overflow Behavior:
emilmont 1:fdd22bb7aa52 66 * \par
emilmont 1:fdd22bb7aa52 67 * The function uses saturating arithmetic.
emilmont 1:fdd22bb7aa52 68 * Results outside of the allowable Q7 range [0x80 0x7F] will be saturated.
emilmont 1:fdd22bb7aa52 69 * \note
emilmont 1:fdd22bb7aa52 70 * In order to apply rounding, the library should be rebuilt with the ROUNDING macro
emilmont 1:fdd22bb7aa52 71 * defined in the preprocessor section of project options.
emilmont 1:fdd22bb7aa52 72 */
emilmont 1:fdd22bb7aa52 73
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 void arm_float_to_q7(
emilmont 1:fdd22bb7aa52 76 float32_t * pSrc,
emilmont 1:fdd22bb7aa52 77 q7_t * pDst,
emilmont 1:fdd22bb7aa52 78 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 79 {
emilmont 1:fdd22bb7aa52 80 float32_t *pIn = pSrc; /* Src pointer */
emilmont 1:fdd22bb7aa52 81 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 82
emilmont 1:fdd22bb7aa52 83 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 84
emilmont 1:fdd22bb7aa52 85 float32_t in;
emilmont 1:fdd22bb7aa52 86
emilmont 1:fdd22bb7aa52 87 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 88
mbed_official 3:7a284390b0ce 89 #ifndef ARM_MATH_CM0_FAMILY
emilmont 1:fdd22bb7aa52 90
emilmont 1:fdd22bb7aa52 91 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 92
emilmont 1:fdd22bb7aa52 93 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 94 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 95
emilmont 1:fdd22bb7aa52 96 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 97 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 98 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 99 {
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 102 /* C = A * 128 */
emilmont 1:fdd22bb7aa52 103 /* convert from float to q7 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 104 in = *pIn++;
emilmont 1:fdd22bb7aa52 105 in = (in * 128);
mbed_official 5:3762170b6d4d 106 in += in > 0.0f ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 107 *pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
emilmont 1:fdd22bb7aa52 108
emilmont 1:fdd22bb7aa52 109 in = *pIn++;
emilmont 1:fdd22bb7aa52 110 in = (in * 128);
mbed_official 5:3762170b6d4d 111 in += in > 0.0f ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 112 *pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
emilmont 1:fdd22bb7aa52 113
emilmont 1:fdd22bb7aa52 114 in = *pIn++;
emilmont 1:fdd22bb7aa52 115 in = (in * 128);
mbed_official 5:3762170b6d4d 116 in += in > 0.0f ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 117 *pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
emilmont 1:fdd22bb7aa52 118
emilmont 1:fdd22bb7aa52 119 in = *pIn++;
emilmont 1:fdd22bb7aa52 120 in = (in * 128);
mbed_official 5:3762170b6d4d 121 in += in > 0.0f ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 122 *pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
emilmont 1:fdd22bb7aa52 123
emilmont 1:fdd22bb7aa52 124 #else
emilmont 1:fdd22bb7aa52 125
emilmont 1:fdd22bb7aa52 126 /* C = A * 128 */
emilmont 1:fdd22bb7aa52 127 /* convert from float to q7 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 128 *pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
emilmont 1:fdd22bb7aa52 129 *pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
emilmont 1:fdd22bb7aa52 130 *pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
emilmont 1:fdd22bb7aa52 131 *pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
emilmont 1:fdd22bb7aa52 132
emilmont 1:fdd22bb7aa52 133 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 134
emilmont 1:fdd22bb7aa52 135 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 136 blkCnt--;
emilmont 1:fdd22bb7aa52 137 }
emilmont 1:fdd22bb7aa52 138
emilmont 1:fdd22bb7aa52 139 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 140 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 141 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 142
emilmont 1:fdd22bb7aa52 143 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 144 {
emilmont 1:fdd22bb7aa52 145
emilmont 1:fdd22bb7aa52 146 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 147 /* C = A * 128 */
emilmont 1:fdd22bb7aa52 148 /* convert from float to q7 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 149 in = *pIn++;
emilmont 1:fdd22bb7aa52 150 in = (in * 128);
mbed_official 5:3762170b6d4d 151 in += in > 0.0f ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 152 *pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
emilmont 1:fdd22bb7aa52 153
emilmont 1:fdd22bb7aa52 154 #else
emilmont 1:fdd22bb7aa52 155
emilmont 1:fdd22bb7aa52 156 /* C = A * 128 */
emilmont 1:fdd22bb7aa52 157 /* convert from float to q7 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 158 *pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
emilmont 1:fdd22bb7aa52 159
emilmont 1:fdd22bb7aa52 160 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 161
emilmont 1:fdd22bb7aa52 162 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 163 blkCnt--;
emilmont 1:fdd22bb7aa52 164 }
emilmont 1:fdd22bb7aa52 165
emilmont 1:fdd22bb7aa52 166
emilmont 1:fdd22bb7aa52 167 #else
emilmont 1:fdd22bb7aa52 168
emilmont 1:fdd22bb7aa52 169 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 170
emilmont 1:fdd22bb7aa52 171
emilmont 1:fdd22bb7aa52 172 /* Loop over blockSize number of values */
emilmont 1:fdd22bb7aa52 173 blkCnt = blockSize;
emilmont 1:fdd22bb7aa52 174
emilmont 1:fdd22bb7aa52 175 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 176 {
emilmont 1:fdd22bb7aa52 177 #ifdef ARM_MATH_ROUNDING
emilmont 1:fdd22bb7aa52 178 /* C = A * 128 */
emilmont 1:fdd22bb7aa52 179 /* convert from float to q7 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 180 in = *pIn++;
emilmont 1:fdd22bb7aa52 181 in = (in * 128.0f);
emilmont 1:fdd22bb7aa52 182 in += in > 0 ? 0.5f : -0.5f;
emilmont 1:fdd22bb7aa52 183 *pDst++ = (q7_t) (__SSAT((q31_t) (in), 8));
emilmont 1:fdd22bb7aa52 184
emilmont 1:fdd22bb7aa52 185 #else
emilmont 1:fdd22bb7aa52 186
emilmont 1:fdd22bb7aa52 187 /* C = A * 128 */
emilmont 1:fdd22bb7aa52 188 /* convert from float to q7 and then store the results in the destination buffer */
emilmont 1:fdd22bb7aa52 189 *pDst++ = (q7_t) __SSAT((q31_t) (*pIn++ * 128.0f), 8);
emilmont 1:fdd22bb7aa52 190
emilmont 1:fdd22bb7aa52 191 #endif /* #ifdef ARM_MATH_ROUNDING */
emilmont 1:fdd22bb7aa52 192
emilmont 1:fdd22bb7aa52 193 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 194 blkCnt--;
emilmont 1:fdd22bb7aa52 195 }
emilmont 1:fdd22bb7aa52 196
mbed_official 3:7a284390b0ce 197 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emilmont 1:fdd22bb7aa52 198
emilmont 1:fdd22bb7aa52 199 }
emilmont 1:fdd22bb7aa52 200
emilmont 1:fdd22bb7aa52 201 /**
emilmont 1:fdd22bb7aa52 202 * @} end of float_to_x group
emilmont 1:fdd22bb7aa52 203 */