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_q31.c
10 * Description: Multiplies a Q31 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. ------------------------------------------------ */
43 * @ingroup groupMatrix
47 * @addtogroup MatrixScale
52 * @brief Q31 matrix scaling.
53 * @param[in] *pSrc points to input matrix
54 * @param[in] scaleFract fractional portion of the scale factor
55 * @param[in] shift number of bits to shift the result by
56 * @param[out] *pDst points to output matrix structure
57 * @return The function returns either
58 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
61 * <b>Scaling and Overflow Behavior:</b>
63 * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.31 format.
64 * These are multiplied to yield a 2.62 intermediate result and this is shifted with saturation to 1.31 format.
67 arm_status arm_mat_scale_q31(
68 const arm_matrix_instance_q31 * pSrc,
71 arm_matrix_instance_q31 * pDst)
73 q31_t *pIn = pSrc->pData; /* input data matrix pointer */
74 q31_t *pOut = pDst->pData; /* output data matrix pointer */
75 uint32_t numSamples; /* total number of elements in the matrix */
76 int32_t totShift = shift + 1; /* shift to apply after scaling */
77 uint32_t blkCnt; /* loop counters */
78 arm_status status; /* status of matrix scaling */
79 q31_t in1, in2, out1; /* temporary variabels */
81 #ifndef ARM_MATH_CM0_FAMILY
83 q31_t in3, in4, out2, out3, out4; /* temporary variables */
85 #endif // #ifndef ARM_MAT_CM0
87 #ifdef ARM_MATH_MATRIX_CHECK
88 /* Check for matrix mismatch */
89 if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
91 /* Set status as ARM_MATH_SIZE_MISMATCH */
92 status = ARM_MATH_SIZE_MISMATCH;
95 #endif // #ifdef ARM_MATH_MATRIX_CHECK
97 /* Total number of samples in the input matrix */
98 numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
100 #ifndef ARM_MATH_CM0_FAMILY
102 /* Run the below code for Cortex-M4 and Cortex-M3 */
105 blkCnt = numSamples >> 2u;
107 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
108 ** a second loop below computes the remaining 1 to 3 samples. */
111 /* C(m,n) = A(m,n) * k */
112 /* Read values from input */
118 /* multiply input with scaler value */
119 in1 = ((q63_t) in1 * scaleFract) >> 32;
120 in2 = ((q63_t) in2 * scaleFract) >> 32;
121 in3 = ((q63_t) in3 * scaleFract) >> 32;
122 in4 = ((q63_t) in4 * scaleFract) >> 32;
125 out1 = in1 << totShift;
126 out2 = in2 << totShift;
128 /* saturate the results. */
129 if(in1 != (out1 >> totShift))
130 out1 = 0x7FFFFFFF ^ (in1 >> 31);
132 if(in2 != (out2 >> totShift))
133 out2 = 0x7FFFFFFF ^ (in2 >> 31);
135 out3 = in3 << totShift;
136 out4 = in4 << totShift;
141 if(in3 != (out3 >> totShift))
142 out3 = 0x7FFFFFFF ^ (in3 >> 31);
144 if(in4 != (out4 >> totShift))
145 out4 = 0x7FFFFFFF ^ (in4 >> 31);
151 /* update pointers to process next sampels */
156 /* Decrement the numSamples loop counter */
160 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
161 ** No loop unrolling is used. */
162 blkCnt = numSamples % 0x4u;
166 /* Run the below code for Cortex-M0 */
168 /* Initialize blkCnt with number of samples */
171 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
175 /* C(m,n) = A(m,n) * k */
176 /* Scale, saturate and then store the results in the destination buffer. */
179 in2 = ((q63_t) in1 * scaleFract) >> 32;
181 out1 = in2 << totShift;
183 if(in2 != (out1 >> totShift))
184 out1 = 0x7FFFFFFF ^ (in2 >> 31);
188 /* Decrement the numSamples loop counter */
192 /* Set status as ARM_MATH_SUCCESS */
193 status = ARM_MATH_SUCCESS;
196 /* Return to application */
201 * @} end of MatrixScale group