1 /* ---------------------------------------------------------------------- 2 * Project: CMSIS DSP Library 3 * Title: arm_f64_to_q31.c 4 * Description: Converts the elements of the 64 bit floating-point vector to Q31 vector 5 * 6 * $Date: 18 August 2022 7 * $Revision: V1.0.0 8 * 9 * Target Processor: Cortex-M and Cortex-A cores 10 * -------------------------------------------------------------------- */ 11 /* 12 * Copyright (C) 2010-2022 ARM Limited or its affiliates. All rights reserved. 13 * 14 * SPDX-License-Identifier: Apache-2.0 15 * 16 * Licensed under the Apache License, Version 2.0 (the License); you may 17 * not use this file except in compliance with the License. 18 * You may obtain a copy of the License at 19 * 20 * www.apache.org/licenses/LICENSE-2.0 21 * 22 * Unless required by applicable law or agreed to in writing, software 23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT 24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 25 * See the License for the specific language governing permissions and 26 * limitations under the License. 27 */ 28 29 #include "dsp/support_functions.h" 30 31 /** 32 @ingroup groupSupport 33 */ 34 35 36 /** 37 @addtogroup f64_to_x 38 @{ 39 */ 40 41 /** 42 @brief Converts the elements of the 64 bit floating-point vector to Q31 vector. 43 @param[in] pSrc points to the 64 bit floating-point input vector 44 @param[out] pDst points to the Q31 output vector 45 @param[in] blockSize number of samples in each vector 46 47 @par Details 48 The equation used for the conversion process is: 49 <pre> 50 pDst[n] = (q31_t)(pSrc[n] * 2147483648); 0 <= n < blockSize. 51 </pre> 52 53 @par Scaling and Overflow Behavior 54 The function uses saturating arithmetic. 55 Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] are saturated. 56 57 @note 58 In order to apply rounding, the library should be rebuilt with the ROUNDING macro 59 defined in the preprocessor section of project options. 60 */ 61 62 arm_f64_to_q31(const float64_t * pSrc,q31_t * pDst,uint32_t blockSize)63void arm_f64_to_q31( 64 const float64_t * pSrc, 65 q31_t * pDst, 66 uint32_t blockSize) 67 { 68 uint32_t blkCnt; /* Loop counter */ 69 const float64_t *pIn = pSrc; /* Source pointer */ 70 71 #ifdef ARM_MATH_ROUNDING 72 float64_t in; 73 #endif /* #ifdef ARM_MATH_ROUNDING */ 74 75 #if defined (ARM_MATH_LOOPUNROLL) 76 77 /* Loop unrolling: Compute 4 outputs at a time */ 78 blkCnt = blockSize >> 2U; 79 80 while (blkCnt > 0U) 81 { 82 /* C = A * 2147483648 */ 83 84 /* convert from float to Q31 and store result in destination buffer */ 85 #ifdef ARM_MATH_ROUNDING 86 87 in = (*pIn++ * 2147483648.0); 88 in += in > 0.0 ? 0.5 : -0.5; 89 *pDst++ = clip_q63_to_q31((q63_t) (in)); 90 91 in = (*pIn++ * 2147483648.0); 92 in += in > 0.0 ? 0.5 : -0.5; 93 *pDst++ = clip_q63_to_q31((q63_t) (in)); 94 95 in = (*pIn++ * 2147483648.0); 96 in += in > 0.0 ? 0.5 : -0.5; 97 *pDst++ = clip_q63_to_q31((q63_t) (in)); 98 99 in = (*pIn++ * 2147483648.0); 100 in += in > 0.0 ? 0.5 : -0.5; 101 *pDst++ = clip_q63_to_q31((q63_t) (in)); 102 103 #else 104 105 /* C = A * 2147483648 */ 106 /* Convert from float to Q31 and then store the results in the destination buffer */ 107 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0)); 108 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0)); 109 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0)); 110 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0)); 111 112 #endif /* #ifdef ARM_MATH_ROUNDING */ 113 114 /* Decrement loop counter */ 115 blkCnt--; 116 } 117 118 /* Loop unrolling: Compute remaining outputs */ 119 blkCnt = blockSize % 0x4U; 120 121 #else 122 123 /* Initialize blkCnt with number of samples */ 124 blkCnt = blockSize; 125 126 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */ 127 128 while (blkCnt > 0U) 129 { 130 /* C = A * 2147483648 */ 131 132 /* convert from float to Q31 and store result in destination buffer */ 133 #ifdef ARM_MATH_ROUNDING 134 135 in = (*pIn++ * 2147483648.0); 136 in += in > 0.0 ? 0.5 : -0.5; 137 *pDst++ = clip_q63_to_q31((q63_t) (in)); 138 139 #else 140 141 /* C = A * 2147483648 */ 142 /* Convert from float to Q31 and then store the results in the destination buffer */ 143 *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0)); 144 145 #endif /* #ifdef ARM_MATH_ROUNDING */ 146 147 /* Decrement loop counter */ 148 blkCnt--; 149 } 150 151 } 152 153 154 /** 155 @} end of f64_to_x group 156 */ 157
