1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010 ARM Limited. All rights reserved.
7 * Project: CMSIS DSP Library
10 * Description: Floating-point vector subtraction.
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
14 * Version 1.0.10 2011/7/15
15 * Big Endian support added and Merged M0 and M3/M4 Source code.
17 * Version 1.0.3 2010/11/29
18 * Re-organized the CMSIS folders and updated documentation.
20 * Version 1.0.2 2010/11/11
21 * Documentation updated.
23 * Version 1.0.1 2010/10/05
24 * Production release and review comments incorporated.
26 * Version 1.0.0 2010/09/20
27 * Production release and review comments incorporated.
29 * Version 0.0.7 2010/06/10
30 * Misra-C changes done
31 * ---------------------------------------------------------------------------- */
40 * @defgroup BasicSub Vector Subtraction
42 * Element-by-element subtraction of two vectors.
45 * pDst[n] = pSrcA[n] - pSrcB[n], 0 <= n < blockSize.
48 * There are separate functions for floating-point, Q7, Q15, and Q31 data types.
52 * @addtogroup BasicSub
58 * @brief Floating-point vector subtraction.
59 * @param[in] *pSrcA points to the first input vector
60 * @param[in] *pSrcB points to the second input vector
61 * @param[out] *pDst points to the output vector
62 * @param[in] blockSize number of samples in each vector
72 uint32_t blkCnt; /* loop counter */
76 /* Run the below code for Cortex-M4 and Cortex-M3 */
78 blkCnt = blockSize >> 2u;
80 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
81 ** a second loop below computes the remaining 1 to 3 samples. */
85 /* Subtract and then store the results in the destination buffer. */
86 *pDst++ = (*pSrcA++) - (*pSrcB++);
87 *pDst++ = (*pSrcA++) - (*pSrcB++);
88 *pDst++ = (*pSrcA++) - (*pSrcB++);
89 *pDst++ = (*pSrcA++) - (*pSrcB++);
91 /* Decrement the loop counter */
95 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
96 ** No loop unrolling is used. */
97 blkCnt = blockSize % 0x4u;
101 /* Run the below code for Cortex-M0 */
103 /* Initialize blkCnt with number of samples */
106 #endif /* #ifndef ARM_MATH_CM0 */
112 /* Subtract and then store the results in the destination buffer. */
113 *pDst++ = (*pSrcA++) - (*pSrcB++);
115 /* Decrement the loop counter */
121 * @} end of BasicSub group