]>
git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/MatrixFunctions/arm_mat_scale_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_mat_scale_q15.c
10 * Description: Multiplies a Q15 matrix by a scalar.
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 groupMatrix
48 * @addtogroup MatrixScale
53 * @brief Q15 matrix scaling.
54 * @param[in] *pSrc points to input matrix
55 * @param[in] scaleFract fractional portion of the scale factor
56 * @param[in] shift number of bits to shift the result by
57 * @param[out] *pDst points to output matrix structure
58 * @return The function returns either
59 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
62 * <b>Scaling and Overflow Behavior:</b>
64 * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.
65 * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.
68 arm_status
arm_mat_scale_q15(
69 const arm_matrix_instance_q15
* pSrc
,
72 arm_matrix_instance_q15
* pDst
)
74 q15_t
*pIn
= pSrc
->pData
; /* input data matrix pointer */
75 q15_t
*pOut
= pDst
->pData
; /* output data matrix pointer */
76 uint32_t numSamples
; /* total number of elements in the matrix */
77 int32_t totShift
= 15 - shift
; /* total shift to apply after scaling */
78 uint32_t blkCnt
; /* loop counters */
79 arm_status status
; /* status of matrix scaling */
81 #ifndef ARM_MATH_CM0_FAMILY
83 q15_t in1
, in2
, in3
, in4
;
84 q31_t out1
, out2
, out3
, out4
;
87 #endif // #ifndef ARM_MATH_CM0_FAMILY
89 #ifdef ARM_MATH_MATRIX_CHECK
90 /* Check for matrix mismatch */
91 if((pSrc
->numRows
!= pDst
->numRows
) || (pSrc
->numCols
!= pDst
->numCols
))
93 /* Set status as ARM_MATH_SIZE_MISMATCH */
94 status
= ARM_MATH_SIZE_MISMATCH
;
97 #endif // #ifdef ARM_MATH_MATRIX_CHECK
99 /* Total number of samples in the input matrix */
100 numSamples
= (uint32_t) pSrc
->numRows
* pSrc
->numCols
;
102 #ifndef ARM_MATH_CM0_FAMILY
104 /* Run the below code for Cortex-M4 and Cortex-M3 */
106 blkCnt
= numSamples
>> 2;
108 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
109 ** a second loop below computes the remaining 1 to 3 samples. */
112 /* C(m,n) = A(m,n) * k */
113 /* Scale, saturate and then store the results in the destination buffer. */
114 /* Reading 2 inputs from memory */
115 inA1
= _SIMD32_OFFSET(pIn
);
116 inA2
= _SIMD32_OFFSET(pIn
+ 2);
119 /* Scale the inputs and then store the 2 results in the destination buffer
120 * in single cycle by packing the outputs */
121 out1
= (q31_t
) ((q15_t
) (inA1
>> 16) * scaleFract
);
122 out2
= (q31_t
) ((q15_t
) inA1
* scaleFract
);
123 out3
= (q31_t
) ((q15_t
) (inA2
>> 16) * scaleFract
);
124 out4
= (q31_t
) ((q15_t
) inA2
* scaleFract
);
126 out1
= out1
>> totShift
;
127 inA1
= _SIMD32_OFFSET(pIn
+ 4);
128 out2
= out2
>> totShift
;
129 inA2
= _SIMD32_OFFSET(pIn
+ 6);
130 out3
= out3
>> totShift
;
131 out4
= out4
>> totShift
;
133 in1
= (q15_t
) (__SSAT(out1
, 16));
134 in2
= (q15_t
) (__SSAT(out2
, 16));
135 in3
= (q15_t
) (__SSAT(out3
, 16));
136 in4
= (q15_t
) (__SSAT(out4
, 16));
138 _SIMD32_OFFSET(pOut
) = __PKHBT(in2
, in1
, 16);
139 _SIMD32_OFFSET(pOut
+ 2) = __PKHBT(in4
, in3
, 16);
141 /* update pointers to process next sampels */
146 /* Decrement the numSamples loop counter */
150 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
151 ** No loop unrolling is used. */
152 blkCnt
= numSamples
% 0x4u
;
156 /* Run the below code for Cortex-M0 */
158 /* Initialize blkCnt with number of samples */
161 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
165 /* C(m,n) = A(m,n) * k */
166 /* Scale, saturate and then store the results in the destination buffer. */
168 (q15_t
) (__SSAT(((q31_t
) (*pIn
++) * scaleFract
) >> totShift
, 16));
170 /* Decrement the numSamples loop counter */
173 /* Set status as ARM_MATH_SUCCESS */
174 status
= ARM_MATH_SUCCESS
;
177 /* Return to application */
182 * @} end of MatrixScale group