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Diff: cmsis_dsp/BasicMathFunctions/arm_negate_f32.c
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diff -r 83d0537c7d84 -r fdd22bb7aa52 cmsis_dsp/BasicMathFunctions/arm_negate_f32.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/BasicMathFunctions/arm_negate_f32.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,137 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_negate_f32.c +* +* Description: Negates floating-point vectors. +* +* 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 negate Vector Negate + * + * Negates the elements of a vector. + * + * <pre> + * pDst[n] = -pSrc[n], 0 <= n < blockSize. + * </pre> + */ + +/** + * @addtogroup negate + * @{ + */ + +/** + * @brief Negates the elements of a floating-point vector. + * @param[in] *pSrc points to the input vector + * @param[out] *pDst points to the output vector + * @param[in] 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 */ + + +#ifndef ARM_MATH_CM0 + +/* 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) + { + /* read inputs from source */ + in1 = *pSrc; + in2 = *(pSrc + 1); + in3 = *(pSrc + 2); + in4 = *(pSrc + 3); + + /* negate the input */ + in1 = -in1; + in2 = -in2; + in3 = -in3; + in4 = -in4; + + /* store the result to destination */ + *pDst = in1; + *(pDst + 1) = in2; + *(pDst + 2) = in3; + *(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 */ + /* Negate and then store the results in the destination buffer. */ + *pDst++ = -*pSrc++; + + /* Decrement the loop counter */ + blkCnt--; + } +} + +/** + * @} end of negate group + */