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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_real_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_real_q15.c
10 * Description: Q15 complex by real 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 CmplxByRealMult
54 * @brief Q15 complex-by-real multiplication
55 * @param[in] *pSrcCmplx points to the complex input vector
56 * @param[in] *pSrcReal points to the real input vector
57 * @param[out] *pCmplxDst points to the complex output vector
58 * @param[in] numSamples number of samples in each vector
61 * <b>Scaling and Overflow Behavior:</b>
63 * The function uses saturating arithmetic.
64 * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.
67 void arm_cmplx_mult_real_q15(
73 q15_t in
; /* Temporary variable to store input value */
75 #ifndef ARM_MATH_CM0_FAMILY
77 /* Run the below code for Cortex-M4 and Cortex-M3 */
78 uint32_t blkCnt
; /* loop counters */
79 q31_t inA1
, inA2
; /* Temporary variables to hold input data */
80 q31_t inB1
; /* Temporary variables to hold input data */
81 q15_t out1
, out2
, out3
, out4
; /* Temporary variables to hold output data */
82 q31_t mul1
, mul2
, mul3
, mul4
; /* Temporary variables to hold intermediate data */
85 blkCnt
= numSamples
>> 2u;
87 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
88 ** a second loop below computes the remaining 1 to 3 samples. */
91 /* C[2 * i] = A[2 * i] * B[i]. */
92 /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
93 /* read complex number both real and imaginary from complex input buffer */
94 inA1
= *__SIMD32(pSrcCmplx
)++;
95 /* read two real values at a time from real input buffer */
96 inB1
= *__SIMD32(pSrcReal
)++;
97 /* read complex number both real and imaginary from complex input buffer */
98 inA2
= *__SIMD32(pSrcCmplx
)++;
100 /* multiply complex number with real numbers */
101 #ifndef ARM_MATH_BIG_ENDIAN
103 mul1
= (q31_t
) ((q15_t
) (inA1
) * (q15_t
) (inB1
));
104 mul2
= (q31_t
) ((q15_t
) (inA1
>> 16) * (q15_t
) (inB1
));
105 mul3
= (q31_t
) ((q15_t
) (inA2
) * (q15_t
) (inB1
>> 16));
106 mul4
= (q31_t
) ((q15_t
) (inA2
>> 16) * (q15_t
) (inB1
>> 16));
110 mul2
= (q31_t
) ((q15_t
) (inA1
>> 16) * (q15_t
) (inB1
>> 16));
111 mul1
= (q31_t
) ((q15_t
) inA1
* (q15_t
) (inB1
>> 16));
112 mul4
= (q31_t
) ((q15_t
) (inA2
>> 16) * (q15_t
) inB1
);
113 mul3
= (q31_t
) ((q15_t
) inA2
* (q15_t
) inB1
);
115 #endif // #ifndef ARM_MATH_BIG_ENDIAN
117 /* saturate the result */
118 out1
= (q15_t
) __SSAT(mul1
>> 15u, 16);
119 out2
= (q15_t
) __SSAT(mul2
>> 15u, 16);
120 out3
= (q15_t
) __SSAT(mul3
>> 15u, 16);
121 out4
= (q15_t
) __SSAT(mul4
>> 15u, 16);
123 /* pack real and imaginary outputs and store them to destination */
124 *__SIMD32(pCmplxDst
)++ = __PKHBT(out1
, out2
, 16);
125 *__SIMD32(pCmplxDst
)++ = __PKHBT(out3
, out4
, 16);
127 inA1
= *__SIMD32(pSrcCmplx
)++;
128 inB1
= *__SIMD32(pSrcReal
)++;
129 inA2
= *__SIMD32(pSrcCmplx
)++;
131 #ifndef ARM_MATH_BIG_ENDIAN
133 mul1
= (q31_t
) ((q15_t
) (inA1
) * (q15_t
) (inB1
));
134 mul2
= (q31_t
) ((q15_t
) (inA1
>> 16) * (q15_t
) (inB1
));
135 mul3
= (q31_t
) ((q15_t
) (inA2
) * (q15_t
) (inB1
>> 16));
136 mul4
= (q31_t
) ((q15_t
) (inA2
>> 16) * (q15_t
) (inB1
>> 16));
140 mul2
= (q31_t
) ((q15_t
) (inA1
>> 16) * (q15_t
) (inB1
>> 16));
141 mul1
= (q31_t
) ((q15_t
) inA1
* (q15_t
) (inB1
>> 16));
142 mul4
= (q31_t
) ((q15_t
) (inA2
>> 16) * (q15_t
) inB1
);
143 mul3
= (q31_t
) ((q15_t
) inA2
* (q15_t
) inB1
);
145 #endif // #ifndef ARM_MATH_BIG_ENDIAN
147 out1
= (q15_t
) __SSAT(mul1
>> 15u, 16);
148 out2
= (q15_t
) __SSAT(mul2
>> 15u, 16);
149 out3
= (q15_t
) __SSAT(mul3
>> 15u, 16);
150 out4
= (q15_t
) __SSAT(mul4
>> 15u, 16);
152 *__SIMD32(pCmplxDst
)++ = __PKHBT(out1
, out2
, 16);
153 *__SIMD32(pCmplxDst
)++ = __PKHBT(out3
, out4
, 16);
155 /* Decrement the numSamples loop counter */
159 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
160 ** No loop unrolling is used. */
161 blkCnt
= numSamples
% 0x4u
;
165 /* C[2 * i] = A[2 * i] * B[i]. */
166 /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
168 /* store the result in the destination buffer. */
170 (q15_t
) __SSAT((((q31_t
) (*pSrcCmplx
++) * (in
)) >> 15), 16);
172 (q15_t
) __SSAT((((q31_t
) (*pSrcCmplx
++) * (in
)) >> 15), 16);
174 /* Decrement the numSamples loop counter */
180 /* Run the below code for Cortex-M0 */
182 while(numSamples
> 0u)
184 /* realOut = realA * realB. */
185 /* imagOut = imagA * realB. */
187 /* store the result in the destination buffer. */
189 (q15_t
) __SSAT((((q31_t
) (*pSrcCmplx
++) * (in
)) >> 15), 16);
191 (q15_t
) __SSAT((((q31_t
) (*pSrcCmplx
++) * (in
)) >> 15), 16);
193 /* Decrement the numSamples loop counter */
197 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
202 * @} end of CmplxByRealMult group