1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
4 * $Date: 17. January 2013
7 * Project: CMSIS DSP Library
8 * Title: arm_cmplx_mag_squared_q15.c
10 * Description: Q15 complex magnitude squared.
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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15 * modification, are permitted provided that the following conditions
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27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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39 * ---------------------------------------------------------------------------- */
44 * @ingroup groupCmplxMath
48 * @addtogroup cmplx_mag_squared
53 * @brief Q15 complex magnitude squared
54 * @param *pSrc points to the complex input vector
55 * @param *pDst points to the real output vector
56 * @param numSamples number of complex samples in the input vector
59 * <b>Scaling and Overflow Behavior:</b>
61 * The function implements 1.15 by 1.15 multiplications and finally output is converted into 3.13 format.
64 void arm_cmplx_mag_squared_q15(
69 q31_t acc0, acc1; /* Accumulators */
71 #ifndef ARM_MATH_CM0_FAMILY
73 /* Run the below code for Cortex-M4 and Cortex-M3 */
74 uint32_t blkCnt; /* loop counter */
75 q31_t in1, in2, in3, in4;
79 blkCnt = numSamples >> 2u;
81 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
82 ** a second loop below computes the remaining 1 to 3 samples. */
85 /* C[0] = (A[0] * A[0] + A[1] * A[1]) */
86 in1 = *__SIMD32(pSrc)++;
87 in2 = *__SIMD32(pSrc)++;
88 in3 = *__SIMD32(pSrc)++;
89 in4 = *__SIMD32(pSrc)++;
91 acc0 = __SMUAD(in1, in1);
92 acc1 = __SMUAD(in2, in2);
93 acc2 = __SMUAD(in3, in3);
94 acc3 = __SMUAD(in4, in4);
96 /* store the result in 3.13 format in the destination buffer. */
97 *pDst++ = (q15_t) (acc0 >> 17);
98 *pDst++ = (q15_t) (acc1 >> 17);
99 *pDst++ = (q15_t) (acc2 >> 17);
100 *pDst++ = (q15_t) (acc3 >> 17);
102 /* Decrement the loop counter */
106 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
107 ** No loop unrolling is used. */
108 blkCnt = numSamples % 0x4u;
112 /* C[0] = (A[0] * A[0] + A[1] * A[1]) */
113 in1 = *__SIMD32(pSrc)++;
114 acc0 = __SMUAD(in1, in1);
116 /* store the result in 3.13 format in the destination buffer. */
117 *pDst++ = (q15_t) (acc0 >> 17);
119 /* Decrement the loop counter */
125 /* Run the below code for Cortex-M0 */
126 q15_t real, imag; /* Temporary variables to store real and imaginary values */
128 while(numSamples > 0u)
130 /* out = ((real * real) + (imag * imag)) */
133 acc0 = (real * real);
134 acc1 = (imag * imag);
135 /* store the result in 3.13 format in the destination buffer. */
136 *pDst++ = (q15_t) (((q63_t) acc0 + acc1) >> 17);
138 /* Decrement the loop counter */
142 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
147 * @} end of cmplx_mag_squared group