1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010 ARM Limited. All rights reserved.
7 * Project: CMSIS DSP Library
8 * Title: arm_offset_q31.c
10 * Description: Q31 vector offset.
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 * -------------------------------------------------------------------- */
45 * @brief Adds a constant offset to a Q31 vector.
46 * @param[in] *pSrc points to the input vector
47 * @param[in] offset is the offset to be added
48 * @param[out] *pDst points to the output vector
49 * @param[in] blockSize number of samples in the vector
52 * <b>Scaling and Overflow Behavior:</b>
54 * The function uses saturating arithmetic.
55 * Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] are saturated.
64 uint32_t blkCnt; /* loop counter */
68 /* Run the below code for Cortex-M4 and Cortex-M3 */
72 blkCnt = blockSize >> 2u;
74 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
75 ** a second loop below computes the remaining 1 to 3 samples. */
79 /* Add offset and then store the results in the destination buffer. */
80 *pDst++ = __QADD(*pSrc++, offset);
81 *pDst++ = __QADD(*pSrc++, offset);
82 *pDst++ = __QADD(*pSrc++, offset);
83 *pDst++ = __QADD(*pSrc++, offset);
85 /* Decrement the loop counter */
89 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
90 ** No loop unrolling is used. */
91 blkCnt = blockSize % 0x4u;
96 /* Add offset and then store the result in the destination buffer. */
97 *pDst++ = __QADD(*pSrc++, offset);
99 /* Decrement the loop counter */
105 /* Run the below code for Cortex-M0 */
107 /* Initialize blkCnt with number of samples */
113 /* Add offset and then store the result in the destination buffer. */
114 *pDst++ = (q31_t) clip_q63_to_q31((q63_t) * pSrc++ + offset);
116 /* Decrement the loop counter */
120 #endif /* #ifndef ARM_MATH_CM0 */
125 * @} end of offset group