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CMSIS DSP library

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cmsis_dsp/TransformFunctions/arm_rfft_fast_init_f32.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
mbed_official 3:7a284390b0ce 1 /* ----------------------------------------------------------------------
mbed_official 3:7a284390b0ce 2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
mbed_official 3:7a284390b0ce 3 *
mbed_official 3:7a284390b0ce 4 * $Date: 17. January 2013
mbed_official 3:7a284390b0ce 5 * $Revision: V1.4.1
mbed_official 3:7a284390b0ce 6 *
mbed_official 3:7a284390b0ce 7 * Project: CMSIS DSP Library
mbed_official 3:7a284390b0ce 8 * Title: arm_cfft_init_f32.c
mbed_official 3:7a284390b0ce 9 *
mbed_official 3:7a284390b0ce 10 * Description: Split Radix Decimation in Frequency CFFT Floating point processing function
mbed_official 3:7a284390b0ce 11 *
mbed_official 3:7a284390b0ce 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
mbed_official 3:7a284390b0ce 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.
mbed_official 3:7a284390b0ce 39 * -------------------------------------------------------------------- */
mbed_official 3:7a284390b0ce 40
mbed_official 3:7a284390b0ce 41 #include "arm_math.h"
mbed_official 3:7a284390b0ce 42 #include "arm_common_tables.h"
mbed_official 3:7a284390b0ce 43
mbed_official 3:7a284390b0ce 44 /**
mbed_official 3:7a284390b0ce 45 * @ingroup groupTransforms
mbed_official 3:7a284390b0ce 46 */
mbed_official 3:7a284390b0ce 47
mbed_official 3:7a284390b0ce 48 /**
mbed_official 3:7a284390b0ce 49 * @addtogroup RealFFT
mbed_official 3:7a284390b0ce 50 * @{
mbed_official 3:7a284390b0ce 51 */
mbed_official 3:7a284390b0ce 52
mbed_official 3:7a284390b0ce 53 /**
mbed_official 3:7a284390b0ce 54 * @brief Initialization function for the floating-point real FFT.
mbed_official 3:7a284390b0ce 55 * @param[in,out] *S points to an arm_rfft_fast_instance_f32 structure.
mbed_official 3:7a284390b0ce 56 * @param[in] fftLen length of the Real Sequence.
mbed_official 3:7a284390b0ce 57 * @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
mbed_official 3:7a284390b0ce 58 *
mbed_official 3:7a284390b0ce 59 * \par Description:
mbed_official 3:7a284390b0ce 60 * \par
mbed_official 3:7a284390b0ce 61 * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
mbed_official 3:7a284390b0ce 62 * Set(=1) ifftFlag for calculation of CIFFT otherwise RFFT is calculated
mbed_official 3:7a284390b0ce 63 * \par
mbed_official 3:7a284390b0ce 64 * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
mbed_official 3:7a284390b0ce 65 * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
mbed_official 3:7a284390b0ce 66 * \par
mbed_official 3:7a284390b0ce 67 * The parameter <code>fftLen</code> Specifies length of RFFT/CIFFT process. Supported FFT Lengths are 16, 32, 64, 128, 256, 512, 1024, 2048, 4096.
mbed_official 3:7a284390b0ce 68 * \par
mbed_official 3:7a284390b0ce 69 * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
mbed_official 3:7a284390b0ce 70 */
mbed_official 3:7a284390b0ce 71 arm_status arm_rfft_fast_init_f32(
mbed_official 3:7a284390b0ce 72 arm_rfft_fast_instance_f32 * S,
mbed_official 3:7a284390b0ce 73 uint16_t fftLen)
mbed_official 3:7a284390b0ce 74 {
mbed_official 3:7a284390b0ce 75 arm_cfft_instance_f32 * Sint;
mbed_official 3:7a284390b0ce 76 /* Initialise the default arm status */
mbed_official 3:7a284390b0ce 77 arm_status status = ARM_MATH_SUCCESS;
mbed_official 3:7a284390b0ce 78 /* Initialise the FFT length */
mbed_official 3:7a284390b0ce 79 Sint = &(S->Sint);
mbed_official 3:7a284390b0ce 80 Sint->fftLen = fftLen/2;
mbed_official 3:7a284390b0ce 81 S->fftLenRFFT = fftLen;
mbed_official 3:7a284390b0ce 82 /* Initialise the Twiddle coefficient pointer */
mbed_official 3:7a284390b0ce 83 // S->pTwiddle = (float32_t *) twiddleCoef;
mbed_official 3:7a284390b0ce 84
mbed_official 3:7a284390b0ce 85 /* Initializations of structure parameters depending on the FFT length */
mbed_official 3:7a284390b0ce 86 switch (Sint->fftLen)
mbed_official 3:7a284390b0ce 87 {
mbed_official 3:7a284390b0ce 88 case 4096u:
mbed_official 3:7a284390b0ce 89 /* Initializations of structure parameters for 4096 point FFT */
mbed_official 3:7a284390b0ce 90 /* Initialise the bit reversal table length */
mbed_official 3:7a284390b0ce 91 Sint->bitRevLength = ARMBITREVINDEXTABLE4096_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 92 /* Initialise the bit reversal table pointer */
mbed_official 3:7a284390b0ce 93 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable4096;
mbed_official 3:7a284390b0ce 94 /* Initialise the 1/fftLen Value */
mbed_official 3:7a284390b0ce 95 break;
mbed_official 3:7a284390b0ce 96 case 2048u:
mbed_official 3:7a284390b0ce 97 Sint->bitRevLength = ARMBITREVINDEXTABLE2048_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 98 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
mbed_official 3:7a284390b0ce 99 break;
mbed_official 3:7a284390b0ce 100 case 1024u:
mbed_official 3:7a284390b0ce 101 Sint->bitRevLength = ARMBITREVINDEXTABLE1024_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 102 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
mbed_official 3:7a284390b0ce 103 break;
mbed_official 3:7a284390b0ce 104 case 512u:
mbed_official 3:7a284390b0ce 105 Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 106 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
mbed_official 3:7a284390b0ce 107 break;
mbed_official 3:7a284390b0ce 108 case 256u:
mbed_official 3:7a284390b0ce 109 Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 110 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
mbed_official 3:7a284390b0ce 111 break;
mbed_official 3:7a284390b0ce 112 case 128u:
mbed_official 3:7a284390b0ce 113 Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 114 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
mbed_official 3:7a284390b0ce 115 break;
mbed_official 3:7a284390b0ce 116 case 64u:
mbed_official 3:7a284390b0ce 117 Sint->bitRevLength = ARMBITREVINDEXTABLE__64_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 118 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
mbed_official 3:7a284390b0ce 119 break;
mbed_official 3:7a284390b0ce 120 case 32u:
mbed_official 3:7a284390b0ce 121 Sint->bitRevLength = ARMBITREVINDEXTABLE__32_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 122 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
mbed_official 3:7a284390b0ce 123 break;
mbed_official 3:7a284390b0ce 124 case 16u:
mbed_official 3:7a284390b0ce 125 Sint->bitRevLength = ARMBITREVINDEXTABLE__16_TABLE_LENGTH;
mbed_official 3:7a284390b0ce 126 Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
mbed_official 3:7a284390b0ce 127 break;
mbed_official 3:7a284390b0ce 128 default:
mbed_official 3:7a284390b0ce 129 /* Reporting argument error if fftSize is not valid value */
mbed_official 3:7a284390b0ce 130 status = ARM_MATH_ARGUMENT_ERROR;
mbed_official 3:7a284390b0ce 131 break;
mbed_official 3:7a284390b0ce 132 }
mbed_official 3:7a284390b0ce 133
mbed_official 3:7a284390b0ce 134 return (status);
mbed_official 3:7a284390b0ce 135 }
mbed_official 3:7a284390b0ce 136
mbed_official 3:7a284390b0ce 137 /**
mbed_official 3:7a284390b0ce 138 * @} end of RealFFT group
mbed_official 3:7a284390b0ce 139 */