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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/MatrixFunctions/arm_mat_scale_f32.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_f32.c
10 * Description: Multiplies a floating-point 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 * @defgroup MatrixScale Matrix Scale
50 * Multiplies a matrix by a scalar. This is accomplished by multiplying each element in the
51 * matrix by the scalar. For example:
52 * \image html MatrixScale.gif "Matrix Scaling of a 3 x 3 matrix"
54 * The function checks to make sure that the input and output matrices are of the same size.
56 * In the fixed-point Q15 and Q31 functions, <code>scale</code> is represented by
57 * a fractional multiplication <code>scaleFract</code> and an arithmetic shift <code>shift</code>.
58 * The shift allows the gain of the scaling operation to exceed 1.0.
59 * The overall scale factor applied to the fixed-point data is
61 * scale = scaleFract * 2^shift.
66 * @addtogroup MatrixScale
71 * @brief Floating-point matrix scaling.
72 * @param[in] *pSrc points to input matrix structure
73 * @param[in] scale scale factor to be applied
74 * @param[out] *pDst points to output matrix structure
75 * @return The function returns either <code>ARM_MATH_SIZE_MISMATCH</code>
76 * or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
80 arm_status
arm_mat_scale_f32(
81 const arm_matrix_instance_f32
* pSrc
,
83 arm_matrix_instance_f32
* pDst
)
85 float32_t
*pIn
= pSrc
->pData
; /* input data matrix pointer */
86 float32_t
*pOut
= pDst
->pData
; /* output data matrix pointer */
87 uint32_t numSamples
; /* total number of elements in the matrix */
88 uint32_t blkCnt
; /* loop counters */
89 arm_status status
; /* status of matrix scaling */
91 #ifndef ARM_MATH_CM0_FAMILY
93 float32_t in1
, in2
, in3
, in4
; /* temporary variables */
94 float32_t out1
, out2
, out3
, out4
; /* temporary variables */
96 #endif // #ifndef ARM_MATH_CM0_FAMILY
98 #ifdef ARM_MATH_MATRIX_CHECK
99 /* Check for matrix mismatch condition */
100 if((pSrc
->numRows
!= pDst
->numRows
) || (pSrc
->numCols
!= pDst
->numCols
))
102 /* Set status as ARM_MATH_SIZE_MISMATCH */
103 status
= ARM_MATH_SIZE_MISMATCH
;
106 #endif /* #ifdef ARM_MATH_MATRIX_CHECK */
108 /* Total number of samples in the input matrix */
109 numSamples
= (uint32_t) pSrc
->numRows
* pSrc
->numCols
;
111 #ifndef ARM_MATH_CM0_FAMILY
113 /* Run the below code for Cortex-M4 and Cortex-M3 */
116 blkCnt
= numSamples
>> 2;
118 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
119 ** a second loop below computes the remaining 1 to 3 samples. */
122 /* C(m,n) = A(m,n) * scale */
123 /* Scaling and results are stored in the destination buffer. */
140 /* update pointers to process next sampels */
144 /* Decrement the numSamples loop counter */
148 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
149 ** No loop unrolling is used. */
150 blkCnt
= numSamples
% 0x4u
;
154 /* Run the below code for Cortex-M0 */
156 /* Initialize blkCnt with number of samples */
159 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
163 /* C(m,n) = A(m,n) * scale */
164 /* The results are stored in the destination buffer. */
165 *pOut
++ = (*pIn
++) * scale
;
167 /* Decrement the loop counter */
171 /* Set status as ARM_MATH_SUCCESS */
172 status
= ARM_MATH_SUCCESS
;
175 /* Return to application */
180 * @} end of MatrixScale group