/* ----------------------------------------------------------------------
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* Copyright (C) 2010-2012 ARM Limited. All rights reserved.
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*
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* $Date: 17. January 2013
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* $Revision: V1.4.0
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*
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* Project: CMSIS DSP Library
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* Title: arm_linear_interp_example_f32.c
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*
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* Description: Example code demonstrating usage of sin function
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* and uses linear interpolation to get higher precision
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*
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* Target Processor: Cortex-M4/Cortex-M3
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of ARM LIMITED nor the names of its contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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* -------------------------------------------------------------------- */
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/**
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* @ingroup groupExamples
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*/
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/**
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* @defgroup LinearInterpExample Linear Interpolate Example
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*
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* <b> CMSIS DSP Software Library -- Linear Interpolate Example </b>
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*
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* <b> Description </b>
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* This example demonstrates usage of linear interpolate modules and fast math modules.
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* Method 1 uses fast math sine function to calculate sine values using cubic interpolation and method 2 uses
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* linear interpolation function and results are compared to reference output.
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* Example shows linear interpolation function can be used to get higher precision compared to fast math sin calculation.
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*
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* \par Block Diagram:
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* \par
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* \image html linearInterpExampleMethod1.gif "Method 1: Sine caluclation using fast math"
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* \par
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* \image html linearInterpExampleMethod2.gif "Method 2: Sine caluclation using interpolation function"
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*
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* \par Variables Description:
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* \par
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* \li \c testInputSin_f32 points to the input values for sine calculation
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* \li \c testRefSinOutput32_f32 points to the reference values caculated from sin() matlab function
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* \li \c testOutput points to output buffer calculation from cubic interpolation
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* \li \c testLinIntOutput points to output buffer calculation from linear interpolation
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* \li \c snr1 Signal to noise ratio for reference and cubic interpolation output
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* \li \c snr2 Signal to noise ratio for reference and linear interpolation output
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*
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* \par CMSIS DSP Software Library Functions Used:
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* \par
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* - arm_sin_f32()
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* - arm_linear_interp_f32()
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*
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* <b> Refer </b>
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* \link arm_linear_interp_example_f32.c \endlink
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*
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*/
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/** \example arm_linear_interp_example_f32.c
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*/
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#include "arm_math.h"
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#include "math_helper.h"
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#define SNR_THRESHOLD 90
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#define TEST_LENGTH_SAMPLES 10
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#define XSPACING (0.00005f)
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/* ----------------------------------------------------------------------
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* Test input data for F32 SIN function
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* Generated by the MATLAB rand() function
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* randn('state', 0)
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* xi = (((1/4.18318581819710)* randn(blockSize, 1) * 2* pi));
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* --------------------------------------------------------------------*/
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float32_t testInputSin_f32[TEST_LENGTH_SAMPLES] =
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{
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-0.649716504673081170, -2.501723745497831200,
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0.188250329003310100, 0.432092748487532540,
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-1.722010988459680800, 1.788766476323060600,
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1.786136060975809500, -0.056525543169408797,
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0.491596272728153760, 0.262309671126153390
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};
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/*------------------------------------------------------------------------------
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* Reference out of SIN F32 function for Block Size = 10
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* Calculated from sin(testInputSin_f32)
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*------------------------------------------------------------------------------*/
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float32_t testRefSinOutput32_f32[TEST_LENGTH_SAMPLES] =
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{
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-0.604960695383043530, -0.597090287967934840,
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0.187140422442966500, 0.418772124875992690,
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-0.988588831792106880, 0.976338412038794010,
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0.976903856413481100, -0.056495446835214236,
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0.472033731854734240, 0.259311907228582830
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};
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/*------------------------------------------------------------------------------
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* Method 1: Test out Buffer Calculated from Cubic Interpolation
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*------------------------------------------------------------------------------*/
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float32_t testOutput[TEST_LENGTH_SAMPLES];
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/*------------------------------------------------------------------------------
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* Method 2: Test out buffer Calculated from Linear Interpolation
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*------------------------------------------------------------------------------*/
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float32_t testLinIntOutput[TEST_LENGTH_SAMPLES];
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/*------------------------------------------------------------------------------
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* External table used for linear interpolation
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*------------------------------------------------------------------------------*/
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extern float arm_linear_interep_table[188495];
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/* ----------------------------------------------------------------------
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* Global Variables for caluclating SNR's for Method1 & Method 2
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* ------------------------------------------------------------------- */
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float32_t snr1;
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float32_t snr2;
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/* ----------------------------------------------------------------------------
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* Calculation of Sine values from Cubic Interpolation and Linear interpolation
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* ---------------------------------------------------------------------------- */
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int32_t main(void)
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{
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uint32_t i;
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arm_status status;
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arm_linear_interp_instance_f32 S = {188495, -3.141592653589793238, XSPACING, &arm_linear_interep_table[0]};
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/*------------------------------------------------------------------------------
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* Method 1: Test out Calculated from Cubic Interpolation
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*------------------------------------------------------------------------------*/
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for(i=0; i< TEST_LENGTH_SAMPLES; i++)
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{
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testOutput[i] = arm_sin_f32(testInputSin_f32[i]);
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}
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/*------------------------------------------------------------------------------
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* Method 2: Test out Calculated from Cubic Interpolation and Linear interpolation
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*------------------------------------------------------------------------------*/
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for(i=0; i< TEST_LENGTH_SAMPLES; i++)
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{
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testLinIntOutput[i] = arm_linear_interp_f32(&S, testInputSin_f32[i]);
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}
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/*------------------------------------------------------------------------------
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* SNR calculation for method 1
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*------------------------------------------------------------------------------*/
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snr1 = arm_snr_f32(testRefSinOutput32_f32, testOutput, 2);
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/*------------------------------------------------------------------------------
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* SNR calculation for method 2
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*------------------------------------------------------------------------------*/
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snr2 = arm_snr_f32(testRefSinOutput32_f32, testLinIntOutput, 2);
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/*------------------------------------------------------------------------------
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* Initialise status depending on SNR calculations
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*------------------------------------------------------------------------------*/
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if ( snr2 > snr1)
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{
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status = ARM_MATH_SUCCESS;
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}
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else
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{
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status = ARM_MATH_TEST_FAILURE;
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}
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/* ----------------------------------------------------------------------
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** Loop here if the signals fail the PASS check.
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** This denotes a test failure
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** ------------------------------------------------------------------- */
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if ( status != ARM_MATH_SUCCESS)
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{
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while (1);
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}
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while (1); /* main function does not return */
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}
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/** \endlink */
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