CMSIS DSP library

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cmsis_dsp/BasicMathFunctions/arm_offset_f32.c

Committer:
emilmont
Date:
2012-11-28
Revision:
1:fdd22bb7aa52
Child:
2:da51fb522205

File content as of revision 1:fdd22bb7aa52:

/* ----------------------------------------------------------------------    
* Copyright (C) 2010 ARM Limited. All rights reserved.    
*    
* $Date:        15. February 2012  
* $Revision:     V1.1.0  
*    
* Project:         CMSIS DSP Library    
* Title:        arm_offset_f32.c    
*    
* Description:    Floating-point vector offset.    
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Version 1.1.0 2012/02/15 
*    Updated with more optimizations, bug fixes and minor API changes.  
*   
* Version 1.0.10 2011/7/15  
*    Big Endian support added and Merged M0 and M3/M4 Source code.   
*    
* Version 1.0.3 2010/11/29   
*    Re-organized the CMSIS folders and updated documentation.    
*     
* Version 1.0.2 2010/11/11    
*    Documentation updated.     
*    
* Version 1.0.1 2010/10/05     
*    Production release and review comments incorporated.    
*    
* Version 1.0.0 2010/09/20     
*    Production release and review comments incorporated.    
*    
* Version 0.0.7  2010/06/10     
*    Misra-C changes done    
* ---------------------------------------------------------------------------- */
#include "arm_math.h"

/**        
 * @ingroup groupMath        
 */

/**        
 * @defgroup offset Vector Offset        
 *        
 * Adds a constant offset to each element of a vector.        
 *        
 * <pre>        
 *     pDst[n] = pSrc[n] + offset,   0 <= n < blockSize.        
 * </pre>        
 *        
 * There are separate functions for floating-point, Q7, Q15, and Q31 data types.        
 */

/**        
 * @addtogroup offset        
 * @{        
 */

/**        
 * @brief  Adds a constant offset to a floating-point vector.        
 * @param[in]  *pSrc points to the input vector        
 * @param[in]  offset is the offset to be added        
 * @param[out]  *pDst points to the output vector        
 * @param[in]  blockSize number of samples in the vector        
 * @return none.        
 */


void arm_offset_f32(
  float32_t * pSrc,
  float32_t offset,
  float32_t * pDst,
  uint32_t blockSize)
{
  uint32_t blkCnt;                               /* loop counter */

#ifndef ARM_MATH_CM0

/* Run the below code for Cortex-M4 and Cortex-M3 */
  float32_t in1, in2, in3, in4;

  /*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 + offset */
    /* Add offset and then store the results in the destination buffer. */
    /* read samples from source */
    in1 = *pSrc;
    in2 = *(pSrc + 1);

    /* add offset to input */
    in1 = in1 + offset;

    /* read samples from source */
    in3 = *(pSrc + 2);

    /* add offset to input */
    in2 = in2 + offset;

    /* read samples from source */
    in4 = *(pSrc + 3);

    /* add offset to input */
    in3 = in3 + offset;

    /* store result to destination */
    *pDst = in1;

    /* add offset to input */
    in4 = in4 + offset;

    /* store result to destination */
    *(pDst + 1) = in2;

    /* store result to destination */
    *(pDst + 2) = in3;

    /* store result to destination */
    *(pDst + 3) = in4;

    /* update pointers to process next samples */
    pSrc += 4u;
    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 */

  while(blkCnt > 0u)
  {
    /* C = A + offset */
    /* Add offset and then store the result in the destination buffer. */
    *pDst++ = (*pSrc++) + offset;

    /* Decrement the loop counter */
    blkCnt--;
  }
}

/**        
 * @} end of offset group        
 */