/* ---------------------------------------------------------------------- * Copyright (C) 2010 ARM Limited. All rights reserved. * * $Date: 29. November 2010 * $Revision: V1.0.3 * * Project: CMSIS DSP Library * Title: arm_negate_f32.c * * Description: Negates floating-point vectors. * * Target Processor: Cortex-M4/Cortex-M3 * * 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 negate Vector Negate * * Negates the elements of a vector. * *
  
 *     pDst[n] = -pSrc[n],   0 <= n < blockSize.  
 * 
*/ /** * @addtogroup negate * @{ */ /** * @brief Negates the elements of a floating-point vector. * @param *pSrc points to the input vector * @param *pDst points to the output vector * @param blockSize number of samples in the vector * @return none. */ void arm_negate_f32( float32_t * pSrc, float32_t * pDst, uint32_t blockSize) { uint32_t blkCnt; /* loop counter */ /*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 */ /* Negate and then store the results in the destination buffer. */ *pDst++ = -*pSrc++; *pDst++ = -*pSrc++; *pDst++ = -*pSrc++; *pDst++ = -*pSrc++; /* 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; while(blkCnt > 0u) { /* C = ~A */ /* Negate and then store the results in the destination buffer. */ *pDst++ = -*pSrc++; /* Decrement the loop counter */ blkCnt--; } } /** * @} end of negate group */