1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010 ARM Limited. All rights reserved.
7 * Project: CMSIS DSP Library
8 * Title: arm_cmplx_conj_q31.c
10 * Description: Q31 complex conjugate.
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.
28 * ---------------------------------------------------------------------------- */
33 * @ingroup groupCmplxMath
37 * @addtogroup cmplx_conj
42 * @brief Q31 complex conjugate.
43 * @param *pSrc points to the input vector
44 * @param *pDst points to the output vector
45 * @param numSamples number of complex samples in each vector
48 * <b>Scaling and Overflow Behavior:</b>
50 * The function uses saturating arithmetic.
51 * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
54 void arm_cmplx_conj_q31(
62 /* Run the below code for Cortex-M4 and Cortex-M3 */
63 uint32_t blkCnt; /* loop counter */
64 q31_t in; /* Input value */
67 blkCnt = numSamples >> 2u;
69 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
70 ** a second loop below computes the remaining 1 to 3 samples. */
73 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
74 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
75 /* Saturated to 0x7fffffff if the input is -1(0x80000000) */
78 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
81 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
84 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
87 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
89 /* Decrement the loop counter */
93 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
94 ** No loop unrolling is used. */
95 blkCnt = numSamples % 0x4u;
99 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
100 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
101 /* Saturated to 0x7fffffff if the input is -1(0x80000000) */
104 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
106 /* Decrement the loop counter */
112 /* Run the below code for Cortex-M0 */
114 while(numSamples > 0u)
116 /* realOut + j (imagOut) = realIn+ j (-1) imagIn */
117 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
121 /* Decrement the loop counter */
125 #endif /* #ifndef ARM_MATH_CM0 */
130 * @} end of cmplx_conj group