arm_sub_q7.c
123 lines
| 3.2 KiB
| text/x-c
|
CLexer
jeandet@pc-de-jeandet3.LAB-LPP.LOCAL
|
r41 | /* ---------------------------------------------------------------------- | ||
| * Copyright (C) 2010 ARM Limited. All rights reserved. | ||||
| * | ||||
| * $Date: 15. July 2011 | ||||
| * $Revision: V1.0.10 | ||||
| * | ||||
| * Project: CMSIS DSP Library | ||||
| * Title: arm_sub_q7.c | ||||
| * | ||||
| * Description: Q7 vector subtraction. | ||||
| * | ||||
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | ||||
| * | ||||
| * 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 | ||||
| */ | ||||
| /** | ||||
| * @addtogroup BasicSub | ||||
| * @{ | ||||
| */ | ||||
| /** | ||||
| * @brief Q7 vector subtraction. | ||||
| * @param[in] *pSrcA points to the first input vector | ||||
| * @param[in] *pSrcB points to the second input vector | ||||
| * @param[out] *pDst points to the output vector | ||||
| * @param[in] blockSize number of samples in each vector | ||||
| * @return none. | ||||
| * | ||||
| * <b>Scaling and Overflow Behavior:</b> | ||||
| * \par | ||||
| * The function uses saturating arithmetic. | ||||
| * Results outside of the allowable Q7 range [0x80 0x7F] will be saturated. | ||||
| */ | ||||
| void arm_sub_q7( | ||||
| q7_t * pSrcA, | ||||
| q7_t * pSrcB, | ||||
| q7_t * pDst, | ||||
| uint32_t blockSize) | ||||
| { | ||||
| uint32_t blkCnt; /* loop counter */ | ||||
| #ifndef ARM_MATH_CM0 | ||||
| /* Run the below code for Cortex-M4 and Cortex-M3 */ | ||||
| /*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 - B */ | ||||
| /* Subtract and then store the results in the destination buffer 4 samples at a time. */ | ||||
| *__SIMD32(pDst)++ = __QSUB8(*__SIMD32(pSrcA)++, *__SIMD32(pSrcB)++); | ||||
| /* 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 - B */ | ||||
| /* Subtract and then store the result in the destination buffer. */ | ||||
| *pDst++ = __SSAT(*pSrcA++ - *pSrcB++, 8); | ||||
| /* Decrement the loop counter */ | ||||
| blkCnt--; | ||||
| } | ||||
| #else | ||||
| /* Run the below code for Cortex-M0 */ | ||||
| /* Initialize blkCnt with number of samples */ | ||||
| blkCnt = blockSize; | ||||
| while(blkCnt > 0u) | ||||
| { | ||||
| /* C = A - B */ | ||||
| /* Subtract and then store the result in the destination buffer. */ | ||||
| *pDst++ = (q7_t) __SSAT((q15_t) * pSrcA++ - *pSrcB++, 8); | ||||
| /* Decrement the loop counter */ | ||||
| blkCnt--; | ||||
| } | ||||
| #endif /* #ifndef ARM_MATH_CM0 */ | ||||
| } | ||||
| /** | ||||
| * @} end of BasicSub group | ||||
| */ | ||||