| /* ---------------------------------------------------------------------- |
| * 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. |
| |
| <pre> |
| pDst[n] = -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 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_NEON_EXPERIMENTAL) |
| float32x4_t vec1; |
| float32x4_t res; |
| |
| /* Compute 4 outputs at a time */ |
| blkCnt = blockSize >> 2U; |
| |
| while (blkCnt > 0U) |
| { |
| /* C = -A */ |
| |
| /* Negate and then store the results in the destination buffer. */ |
| vec1 = vld1q_f32(pSrc); |
| res = vnegq_f32(vec1); |
| vst1q_f32(pDst, res); |
| |
| /* Increment pointers */ |
| pSrc += 4; |
| pDst += 4; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| /* Tail */ |
| blkCnt = blockSize & 0x3; |
| |
| #else |
| #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) */ |
| #endif /* #if defined(ARM_MATH_NEON_EXPERIMENTAL) */ |
| |
| while (blkCnt > 0U) |
| { |
| /* C = -A */ |
| |
| /* Negate and store result in destination buffer. */ |
| *pDst++ = -*pSrc++; |
| |
| /* Decrement loop counter */ |
| blkCnt--; |
| } |
| |
| } |
| |
| /** |
| @} end of BasicNegate group |
| */ |