text: /* ----------------------------------------------------------------------    
  * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  *    
  * $Date:        19. March 2015
  * $Revision: 	V.1.4.5
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:		arm_abs_f32.c    
  *    
  * Description:	Vector absolute value.    
  *    
  * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  *  
  * Redistribution and use in source and binary forms, with or without 
  * modification, are permitted provided that the following conditions
  * are met:
  *   - Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *   - Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the 
  *     distribution.
  *   - Neither the name of ARM LIMITED nor the names of its contributors
  *     may be used to endorse or promote products derived from this
  *     software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.   
  * ---------------------------------------------------------------------------- */
  
  #include "arm_math.h"
  #include <math.h>
  
  /**        
   * @ingroup groupMath        
   */
  
  /**        
   * @defgroup BasicAbs Vector Absolute Value        
   *        
   * Computes the absolute value of a vector on an element-by-element basis.        
   *        
   * <pre>        
   *     pDst[n] = abs(pSrc[n]),   0 <= n < blockSize.        
   * </pre>        
   *        
   * The functions support in-place computation allowing the source and
   * destination pointers to reference the same memory buffer.
   * There are separate functions for floating-point, Q7, Q15, and Q31 data types.
   */
  
  /**        
   * @addtogroup BasicAbs        
   * @{        
   */
  
  /**        
   * @brief Floating-point vector absolute value.        
   * @param[in]       *pSrc points to the input buffer        
   * @param[out]      *pDst points to the output buffer        
   * @param[in]       blockSize number of samples in each vector        
   * @return none.        
   */
  
  void arm_abs_f32(
    float32_t * pSrc,
    float32_t * pDst,
    uint32_t blockSize)
  {
    uint32_t blkCnt;                               /* loop counter */
  
  #ifndef ARM_MATH_CM0_FAMILY
  
    /* Run the below code for Cortex-M4 and Cortex-M3 */
    float32_t in1, in2, in3, in4;                  /* temporary variables */
  
    /*loop Unrolling */
    blkCnt = blockSize >> 2u;
  
    /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
     ** a second loop below computes the remaining 1 to 3 samples. */
    while(blkCnt > 0u)
    {
      /* C = |A| */
      /* Calculate absolute and then store the results in the destination buffer. */
      /* read sample from source */
      in1 = *pSrc;
      in2 = *(pSrc + 1);
      in3 = *(pSrc + 2);
  
      /* find absolute value */
      in1 = fabsf(in1);
  
      /* read sample from source */
      in4 = *(pSrc + 3);
  
      /* find absolute value */
      in2 = fabsf(in2);
  
      /* read sample from source */
      *pDst = in1;
  
      /* find absolute value */
      in3 = fabsf(in3);
  
      /* find absolute value */
      in4 = fabsf(in4);
  
      /* store result to destination */
      *(pDst + 1) = in2;
  
      /* store result to destination */
      *(pDst + 2) = in3;
  
      /* store result to destination */
      *(pDst + 3) = in4;
  
  
      /* Update source pointer to process next sampels */
      pSrc += 4u;
  
      /* Update destination pointer to process next sampels */
      pDst += 4u;
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  
    /* If the blockSize is not a multiple of 4, compute any remaining output samples here.    
     ** No loop unrolling is used. */
    blkCnt = blockSize % 0x4u;
  
  #else
  
    /* Run the below code for Cortex-M0 */
  
    /* Initialize blkCnt with number of samples */
    blkCnt = blockSize;
  
  #endif /*   #ifndef ARM_MATH_CM0_FAMILY   */
  
    while(blkCnt > 0u)
    {
      /* C = |A| */
      /* Calculate absolute and then store the results in the destination buffer. */
      *pDst++ = fabsf(*pSrc++);
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  }
  
  /**        
   * @} end of BasicAbs group        
   */
  