/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_negate_f32.c * Description: Negates floating-point vectors * * $Date: 18. March 2019 * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the License); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an AS IS BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "arm_math.h" /** @ingroup groupMath */ /** @defgroup BasicNegate Vector Negate Negates the elements of a vector.
      pDst[n] = -pSrc[n],   0 <= n < blockSize.
  
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 BasicNegate @{ */ /** @brief Negates the elements of a floating-point vector. @param[in] pSrc points to input vector. @param[out] pDst points to output vector. @param[in] blockSize number of samples in each vector. @return none */ void arm_negate_f32( const float32_t * pSrc, float32_t * pDst, uint32_t blockSize) { uint32_t blkCnt; /* Loop counter */ #if defined (ARM_MATH_LOOPUNROLL) /* Loop unrolling: Compute 4 outputs at a time */ blkCnt = blockSize >> 2U; while (blkCnt > 0U) { /* C = -A */ /* Negate and store result in destination buffer. */ *pDst++ = -*pSrc++; *pDst++ = -*pSrc++; *pDst++ = -*pSrc++; *pDst++ = -*pSrc++; /* Decrement loop counter */ blkCnt--; } /* Loop unrolling: Compute remaining outputs */ blkCnt = blockSize % 0x4U; #else /* Initialize blkCnt with number of samples */ blkCnt = blockSize; #endif /* #if defined (ARM_MATH_LOOPUNROLL) */ while (blkCnt > 0U) { /* C = -A */ /* Negate and store result in destination buffer. */ *pDst++ = -*pSrc++; /* Decrement loop counter */ blkCnt--; } } /** @} end of BasicNegate group */