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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mult_cmplx_q15.c
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_mult_cmplx_q15.c
10 * Description: Q15 complex-by-complex multiplication
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * - Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * - Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in
21 * the documentation and/or other materials provided with the
23 * - Neither the name of ARM LIMITED nor the names of its contributors
24 * may be used to endorse or promote products derived from this
25 * software without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 * -------------------------------------------------------------------- */
44 * @ingroup groupCmplxMath
48 * @addtogroup CmplxByCmplxMult
53 * @brief Q15 complex-by-complex multiplication
54 * @param[in] *pSrcA points to the first input vector
55 * @param[in] *pSrcB points to the second input vector
56 * @param[out] *pDst points to the output vector
57 * @param[in] numSamples number of complex samples in each vector
60 * <b>Scaling and Overflow Behavior:</b>
62 * The function implements 1.15 by 1.15 multiplications and finally output is converted into 3.13 format.
65 void arm_cmplx_mult_cmplx_q15(
71 q15_t a
, b
, c
, d
; /* Temporary variables to store real and imaginary values */
73 #ifndef ARM_MATH_CM0_FAMILY
75 /* Run the below code for Cortex-M4 and Cortex-M3 */
76 uint32_t blkCnt
; /* loop counters */
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[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */
86 /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */
92 /* store the result in 3.13 format in the destination buffer. */
94 (q15_t
) (q31_t
) (((q31_t
) a
* c
) >> 17) - (((q31_t
) b
* d
) >> 17);
95 /* store the result in 3.13 format in the destination buffer. */
97 (q15_t
) (q31_t
) (((q31_t
) a
* d
) >> 17) + (((q31_t
) b
* c
) >> 17);
104 /* store the result in 3.13 format in the destination buffer. */
106 (q15_t
) (q31_t
) (((q31_t
) a
* c
) >> 17) - (((q31_t
) b
* d
) >> 17);
107 /* store the result in 3.13 format in the destination buffer. */
109 (q15_t
) (q31_t
) (((q31_t
) a
* d
) >> 17) + (((q31_t
) b
* c
) >> 17);
116 /* store the result in 3.13 format in the destination buffer. */
118 (q15_t
) (q31_t
) (((q31_t
) a
* c
) >> 17) - (((q31_t
) b
* d
) >> 17);
119 /* store the result in 3.13 format in the destination buffer. */
121 (q15_t
) (q31_t
) (((q31_t
) a
* d
) >> 17) + (((q31_t
) b
* c
) >> 17);
128 /* store the result in 3.13 format in the destination buffer. */
130 (q15_t
) (q31_t
) (((q31_t
) a
* c
) >> 17) - (((q31_t
) b
* d
) >> 17);
131 /* store the result in 3.13 format in the destination buffer. */
133 (q15_t
) (q31_t
) (((q31_t
) a
* d
) >> 17) + (((q31_t
) b
* c
) >> 17);
135 /* Decrement the blockSize loop counter */
139 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
140 ** No loop unrolling is used. */
141 blkCnt
= numSamples
% 0x4u
;
145 /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */
146 /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */
152 /* store the result in 3.13 format in the destination buffer. */
154 (q15_t
) (q31_t
) (((q31_t
) a
* c
) >> 17) - (((q31_t
) b
* d
) >> 17);
155 /* store the result in 3.13 format in the destination buffer. */
157 (q15_t
) (q31_t
) (((q31_t
) a
* d
) >> 17) + (((q31_t
) b
* c
) >> 17);
159 /* Decrement the blockSize loop counter */
165 /* Run the below code for Cortex-M0 */
167 while(numSamples
> 0u)
169 /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */
170 /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */
176 /* store the result in 3.13 format in the destination buffer. */
178 (q15_t
) (q31_t
) (((q31_t
) a
* c
) >> 17) - (((q31_t
) b
* d
) >> 17);
179 /* store the result in 3.13 format in the destination buffer. */
181 (q15_t
) (q31_t
) (((q31_t
) a
* d
) >> 17) + (((q31_t
) b
* c
) >> 17);
183 /* Decrement the blockSize loop counter */
187 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
192 * @} end of CmplxByCmplxMult group