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49 <div class="headertitle">
50 <h1>arm_correlate_q7.c</h1> </div>
52 <div class="contents">
53 <a href="arm__correlate__q7_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* ---------------------------------------------------------------------- </span>
54 <a name="l00002"></a>00002 <span class="comment">* Copyright (C) 2010 ARM Limited. All rights reserved. </span>
55 <a name="l00003"></a>00003 <span class="comment">* </span>
56 <a name="l00004"></a>00004 <span class="comment">* $Date: 15. July 2011 </span>
57 <a name="l00005"></a>00005 <span class="comment">* $Revision: V1.0.10 </span>
58 <a name="l00006"></a>00006 <span class="comment">* </span>
59 <a name="l00007"></a>00007 <span class="comment">* Project: CMSIS DSP Library </span>
60 <a name="l00008"></a>00008 <span class="comment">* Title: arm_correlate_q7.c </span>
61 <a name="l00009"></a>00009 <span class="comment">* </span>
62 <a name="l00010"></a>00010 <span class="comment">* Description: Correlation of Q7 sequences. </span>
63 <a name="l00011"></a>00011 <span class="comment">* </span>
64 <a name="l00012"></a>00012 <span class="comment">* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0</span>
65 <a name="l00013"></a>00013 <span class="comment">* </span>
66 <a name="l00014"></a>00014 <span class="comment">* Version 1.0.10 2011/7/15 </span>
67 <a name="l00015"></a>00015 <span class="comment">* Big Endian support added and Merged M0 and M3/M4 Source code. </span>
68 <a name="l00016"></a>00016 <span class="comment">* </span>
69 <a name="l00017"></a>00017 <span class="comment">* Version 1.0.3 2010/11/29 </span>
70 <a name="l00018"></a>00018 <span class="comment">* Re-organized the CMSIS folders and updated documentation. </span>
71 <a name="l00019"></a>00019 <span class="comment">* </span>
72 <a name="l00020"></a>00020 <span class="comment">* Version 1.0.2 2010/11/11 </span>
73 <a name="l00021"></a>00021 <span class="comment">* Documentation updated. </span>
74 <a name="l00022"></a>00022 <span class="comment">* </span>
75 <a name="l00023"></a>00023 <span class="comment">* Version 1.0.1 2010/10/05 </span>
76 <a name="l00024"></a>00024 <span class="comment">* Production release and review comments incorporated. </span>
77 <a name="l00025"></a>00025 <span class="comment">* </span>
78 <a name="l00026"></a>00026 <span class="comment">* Version 1.0.0 2010/09/20 </span>
79 <a name="l00027"></a>00027 <span class="comment">* Production release and review comments incorporated </span>
80 <a name="l00028"></a>00028 <span class="comment">* </span>
81 <a name="l00029"></a>00029 <span class="comment">* Version 0.0.7 2010/06/10 </span>
82 <a name="l00030"></a>00030 <span class="comment">* Misra-C changes done </span>
83 <a name="l00031"></a>00031 <span class="comment">* </span>
84 <a name="l00032"></a>00032 <span class="comment">* -------------------------------------------------------------------- */</span>
85 <a name="l00033"></a>00033
86 <a name="l00034"></a>00034 <span class="preprocessor">#include "<a class="code" href="arm__math_8h.html">arm_math.h</a>"</span>
87 <a name="l00035"></a>00035
88 <a name="l00065"></a><a class="code" href="group___corr.html#ga284ddcc49e4ac532d52a70d0383c5992">00065</a> <span class="keywordtype">void</span> <a class="code" href="group___corr.html#ga284ddcc49e4ac532d52a70d0383c5992" title="Correlation of Q7 sequences.">arm_correlate_q7</a>(
89 <a name="l00066"></a>00066 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> * pSrcA,
90 <a name="l00067"></a>00067 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>,
91 <a name="l00068"></a>00068 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> * pSrcB,
92 <a name="l00069"></a>00069 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>,
93 <a name="l00070"></a>00070 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> * pDst)
94 <a name="l00071"></a>00071 {
95 <a name="l00072"></a>00072
96 <a name="l00073"></a>00073
97 <a name="l00074"></a>00074 <span class="preprocessor">#ifndef ARM_MATH_CM0</span>
98 <a name="l00075"></a>00075 <span class="preprocessor"></span>
99 <a name="l00076"></a>00076 <span class="comment">/* Run the below code for Cortex-M4 and Cortex-M3 */</span>
100 <a name="l00077"></a>00077
101 <a name="l00078"></a>00078 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *pIn1; <span class="comment">/* inputA pointer */</span>
102 <a name="l00079"></a>00079 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *pIn2; <span class="comment">/* inputB pointer */</span>
103 <a name="l00080"></a>00080 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *pOut = pDst; <span class="comment">/* output pointer */</span>
104 <a name="l00081"></a>00081 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *px; <span class="comment">/* Intermediate inputA pointer */</span>
105 <a name="l00082"></a>00082 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *py; <span class="comment">/* Intermediate inputB pointer */</span>
106 <a name="l00083"></a>00083 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *pSrc1; <span class="comment">/* Intermediate pointers */</span>
107 <a name="l00084"></a>00084 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> sum, acc0, acc1, acc2, acc3; <span class="comment">/* Accumulators */</span>
108 <a name="l00085"></a>00085 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> input1, input2; <span class="comment">/* temporary variables */</span>
109 <a name="l00086"></a>00086 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> in1, in2; <span class="comment">/* temporary variables */</span>
110 <a name="l00087"></a>00087 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> x0, x1, x2, x3, c0, c1; <span class="comment">/* temporary variables for holding input and coefficient values */</span>
111 <a name="l00088"></a>00088 uint32_t j, k = 0u, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3; <span class="comment">/* loop counter */</span>
112 <a name="l00089"></a>00089 int32_t inc = 1;
113 <a name="l00090"></a>00090
114 <a name="l00091"></a>00091
115 <a name="l00092"></a>00092 <span class="comment">/* The algorithm implementation is based on the lengths of the inputs. */</span>
116 <a name="l00093"></a>00093 <span class="comment">/* srcB is always made to slide across srcA. */</span>
117 <a name="l00094"></a>00094 <span class="comment">/* So srcBLen is always considered as shorter or equal to srcALen */</span>
118 <a name="l00095"></a>00095 <span class="comment">/* But CORR(x, y) is reverse of CORR(y, x) */</span>
119 <a name="l00096"></a>00096 <span class="comment">/* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */</span>
120 <a name="l00097"></a>00097 <span class="comment">/* and the destination pointer modifier, inc is set to -1 */</span>
121 <a name="l00098"></a>00098 <span class="comment">/* If srcALen > srcBLen, zero pad has to be done to srcB to make the two inputs of same length */</span>
122 <a name="l00099"></a>00099 <span class="comment">/* But to improve the performance, </span>
123 <a name="l00100"></a>00100 <span class="comment"> * we include zeroes in the output instead of zero padding either of the the inputs*/</span>
124 <a name="l00101"></a>00101 <span class="comment">/* If srcALen > srcBLen, </span>
125 <a name="l00102"></a>00102 <span class="comment"> * (srcALen - srcBLen) zeroes has to included in the starting of the output buffer */</span>
126 <a name="l00103"></a>00103 <span class="comment">/* If srcALen < srcBLen, </span>
127 <a name="l00104"></a>00104 <span class="comment"> * (srcALen - srcBLen) zeroes has to included in the ending of the output buffer */</span>
128 <a name="l00105"></a>00105 <span class="keywordflow">if</span>(srcALen >= srcBLen)
129 <a name="l00106"></a>00106 {
130 <a name="l00107"></a>00107 <span class="comment">/* Initialization of inputA pointer */</span>
131 <a name="l00108"></a>00108 pIn1 = (pSrcA);
132 <a name="l00109"></a>00109
133 <a name="l00110"></a>00110 <span class="comment">/* Initialization of inputB pointer */</span>
134 <a name="l00111"></a>00111 pIn2 = (pSrcB);
135 <a name="l00112"></a>00112
136 <a name="l00113"></a>00113 <span class="comment">/* Number of output samples is calculated */</span>
137 <a name="l00114"></a>00114 outBlockSize = (2u * <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>) - 1u;
138 <a name="l00115"></a>00115
139 <a name="l00116"></a>00116 <span class="comment">/* When srcALen > srcBLen, zero padding is done to srcB </span>
140 <a name="l00117"></a>00117 <span class="comment"> * to make their lengths equal. </span>
141 <a name="l00118"></a>00118 <span class="comment"> * Instead, (outBlockSize - (srcALen + srcBLen - 1)) </span>
142 <a name="l00119"></a>00119 <span class="comment"> * number of output samples are made zero */</span>
143 <a name="l00120"></a>00120 j = outBlockSize - (srcALen + (srcBLen - 1u));
144 <a name="l00121"></a>00121
145 <a name="l00122"></a>00122 <span class="comment">/* Updating the pointer position to non zero value */</span>
146 <a name="l00123"></a>00123 pOut += j;
147 <a name="l00124"></a>00124
148 <a name="l00125"></a>00125 }
149 <a name="l00126"></a>00126 <span class="keywordflow">else</span>
150 <a name="l00127"></a>00127 {
151 <a name="l00128"></a>00128 <span class="comment">/* Initialization of inputA pointer */</span>
152 <a name="l00129"></a>00129 pIn1 = (pSrcB);
153 <a name="l00130"></a>00130
154 <a name="l00131"></a>00131 <span class="comment">/* Initialization of inputB pointer */</span>
155 <a name="l00132"></a>00132 pIn2 = (pSrcA);
156 <a name="l00133"></a>00133
157 <a name="l00134"></a>00134 <span class="comment">/* srcBLen is always considered as shorter or equal to srcALen */</span>
158 <a name="l00135"></a>00135 j = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
159 <a name="l00136"></a>00136 srcBLen = <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>;
160 <a name="l00137"></a>00137 srcALen = j;
161 <a name="l00138"></a>00138
162 <a name="l00139"></a>00139 <span class="comment">/* CORR(x, y) = Reverse order(CORR(y, x)) */</span>
163 <a name="l00140"></a>00140 <span class="comment">/* Hence set the destination pointer to point to the last output sample */</span>
164 <a name="l00141"></a>00141 pOut = pDst + ((srcALen + <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>) - 2u);
165 <a name="l00142"></a>00142
166 <a name="l00143"></a>00143 <span class="comment">/* Destination address modifier is set to -1 */</span>
167 <a name="l00144"></a>00144 inc = -1;
168 <a name="l00145"></a>00145
169 <a name="l00146"></a>00146 }
170 <a name="l00147"></a>00147
171 <a name="l00148"></a>00148 <span class="comment">/* The function is internally </span>
172 <a name="l00149"></a>00149 <span class="comment"> * divided into three parts according to the number of multiplications that has to be </span>
173 <a name="l00150"></a>00150 <span class="comment"> * taken place between inputA samples and inputB samples. In the first part of the </span>
174 <a name="l00151"></a>00151 <span class="comment"> * algorithm, the multiplications increase by one for every iteration. </span>
175 <a name="l00152"></a>00152 <span class="comment"> * In the second part of the algorithm, srcBLen number of multiplications are done. </span>
176 <a name="l00153"></a>00153 <span class="comment"> * In the third part of the algorithm, the multiplications decrease by one </span>
177 <a name="l00154"></a>00154 <span class="comment"> * for every iteration.*/</span>
178 <a name="l00155"></a>00155 <span class="comment">/* The algorithm is implemented in three stages. </span>
179 <a name="l00156"></a>00156 <span class="comment"> * The loop counters of each stage is initiated here. */</span>
180 <a name="l00157"></a>00157 blockSize1 = srcBLen - 1u;
181 <a name="l00158"></a>00158 blockSize2 = srcALen - (srcBLen - 1u);
182 <a name="l00159"></a>00159 blockSize3 = blockSize1;
183 <a name="l00160"></a>00160
184 <a name="l00161"></a>00161 <span class="comment">/* -------------------------- </span>
185 <a name="l00162"></a>00162 <span class="comment"> * Initializations of stage1 </span>
186 <a name="l00163"></a>00163 <span class="comment"> * -------------------------*/</span>
187 <a name="l00164"></a>00164
188 <a name="l00165"></a>00165 <span class="comment">/* sum = x[0] * y[srcBlen - 1] </span>
189 <a name="l00166"></a>00166 <span class="comment"> * sum = x[0] * y[srcBlen - 2] + x[1] * y[srcBlen - 1] </span>
190 <a name="l00167"></a>00167 <span class="comment"> * .... </span>
191 <a name="l00168"></a>00168 <span class="comment"> * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1] </span>
192 <a name="l00169"></a>00169 <span class="comment"> */</span>
193 <a name="l00170"></a>00170
194 <a name="l00171"></a>00171 <span class="comment">/* In this stage the MAC operations are increased by 1 for every iteration. </span>
195 <a name="l00172"></a>00172 <span class="comment"> The count variable holds the number of MAC operations performed */</span>
196 <a name="l00173"></a>00173 count = 1u;
197 <a name="l00174"></a>00174
198 <a name="l00175"></a>00175 <span class="comment">/* Working pointer of inputA */</span>
199 <a name="l00176"></a>00176 px = pIn1;
200 <a name="l00177"></a>00177
201 <a name="l00178"></a>00178 <span class="comment">/* Working pointer of inputB */</span>
202 <a name="l00179"></a>00179 pSrc1 = pIn2 + (srcBLen - 1u);
203 <a name="l00180"></a>00180 py = pSrc1;
204 <a name="l00181"></a>00181
205 <a name="l00182"></a>00182 <span class="comment">/* ------------------------ </span>
206 <a name="l00183"></a>00183 <span class="comment"> * Stage1 process </span>
207 <a name="l00184"></a>00184 <span class="comment"> * ----------------------*/</span>
208 <a name="l00185"></a>00185
209 <a name="l00186"></a>00186 <span class="comment">/* The first stage starts here */</span>
210 <a name="l00187"></a>00187 <span class="keywordflow">while</span>(blockSize1 > 0u)
211 <a name="l00188"></a>00188 {
212 <a name="l00189"></a>00189 <span class="comment">/* Accumulator is made zero for every iteration */</span>
213 <a name="l00190"></a>00190 sum = 0;
214 <a name="l00191"></a>00191
215 <a name="l00192"></a>00192 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
216 <a name="l00193"></a>00193 k = count >> 2;
217 <a name="l00194"></a>00194
218 <a name="l00195"></a>00195 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
219 <a name="l00196"></a>00196 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
220 <a name="l00197"></a>00197 <span class="keywordflow">while</span>(k > 0u)
221 <a name="l00198"></a>00198 {
222 <a name="l00199"></a>00199 <span class="comment">/* x[0] , x[1] */</span>
223 <a name="l00200"></a>00200 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
224 <a name="l00201"></a>00201 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
225 <a name="l00202"></a>00202 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
226 <a name="l00203"></a>00203
227 <a name="l00204"></a>00204 <span class="comment">/* y[srcBLen - 4] , y[srcBLen - 3] */</span>
228 <a name="l00205"></a>00205 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
229 <a name="l00206"></a>00206 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
230 <a name="l00207"></a>00207 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
231 <a name="l00208"></a>00208
232 <a name="l00209"></a>00209 <span class="comment">/* x[0] * y[srcBLen - 4] */</span>
233 <a name="l00210"></a>00210 <span class="comment">/* x[1] * y[srcBLen - 3] */</span>
234 <a name="l00211"></a>00211 sum = __SMLAD(input1, input2, sum);
235 <a name="l00212"></a>00212
236 <a name="l00213"></a>00213 <span class="comment">/* x[2] , x[3] */</span>
237 <a name="l00214"></a>00214 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
238 <a name="l00215"></a>00215 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
239 <a name="l00216"></a>00216 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
240 <a name="l00217"></a>00217
241 <a name="l00218"></a>00218 <span class="comment">/* y[srcBLen - 2] , y[srcBLen - 1] */</span>
242 <a name="l00219"></a>00219 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
243 <a name="l00220"></a>00220 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
244 <a name="l00221"></a>00221 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
245 <a name="l00222"></a>00222
246 <a name="l00223"></a>00223 <span class="comment">/* x[2] * y[srcBLen - 2] */</span>
247 <a name="l00224"></a>00224 <span class="comment">/* x[3] * y[srcBLen - 1] */</span>
248 <a name="l00225"></a>00225 sum = __SMLAD(input1, input2, sum);
249 <a name="l00226"></a>00226
250 <a name="l00227"></a>00227
251 <a name="l00228"></a>00228 <span class="comment">/* Decrement the loop counter */</span>
252 <a name="l00229"></a>00229 k--;
253 <a name="l00230"></a>00230 }
254 <a name="l00231"></a>00231
255 <a name="l00232"></a>00232 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
256 <a name="l00233"></a>00233 <span class="comment"> ** No loop unrolling is used. */</span>
257 <a name="l00234"></a>00234 k = count % 0x4u;
258 <a name="l00235"></a>00235
259 <a name="l00236"></a>00236 <span class="keywordflow">while</span>(k > 0u)
260 <a name="l00237"></a>00237 {
261 <a name="l00238"></a>00238 <span class="comment">/* Perform the multiply-accumulates */</span>
262 <a name="l00239"></a>00239 <span class="comment">/* x[0] * y[srcBLen - 1] */</span>
263 <a name="l00240"></a>00240 sum += (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++ * *py++);
264 <a name="l00241"></a>00241
265 <a name="l00242"></a>00242 <span class="comment">/* Decrement the loop counter */</span>
266 <a name="l00243"></a>00243 k--;
267 <a name="l00244"></a>00244 }
268 <a name="l00245"></a>00245
269 <a name="l00246"></a>00246 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
270 <a name="l00247"></a>00247 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(sum >> 7, 8));
271 <a name="l00248"></a>00248 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
272 <a name="l00249"></a>00249 pOut += inc;
273 <a name="l00250"></a>00250
274 <a name="l00251"></a>00251 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
275 <a name="l00252"></a>00252 py = pSrc1 - count;
276 <a name="l00253"></a>00253 px = pIn1;
277 <a name="l00254"></a>00254
278 <a name="l00255"></a>00255 <span class="comment">/* Increment the MAC count */</span>
279 <a name="l00256"></a>00256 count++;
280 <a name="l00257"></a>00257
281 <a name="l00258"></a>00258 <span class="comment">/* Decrement the loop counter */</span>
282 <a name="l00259"></a>00259 blockSize1--;
283 <a name="l00260"></a>00260 }
284 <a name="l00261"></a>00261
285 <a name="l00262"></a>00262 <span class="comment">/* -------------------------- </span>
286 <a name="l00263"></a>00263 <span class="comment"> * Initializations of stage2 </span>
287 <a name="l00264"></a>00264 <span class="comment"> * ------------------------*/</span>
288 <a name="l00265"></a>00265
289 <a name="l00266"></a>00266 <span class="comment">/* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1] </span>
290 <a name="l00267"></a>00267 <span class="comment"> * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1] </span>
291 <a name="l00268"></a>00268 <span class="comment"> * .... </span>
292 <a name="l00269"></a>00269 <span class="comment"> * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1] </span>
293 <a name="l00270"></a>00270 <span class="comment"> */</span>
294 <a name="l00271"></a>00271
295 <a name="l00272"></a>00272 <span class="comment">/* Working pointer of inputA */</span>
296 <a name="l00273"></a>00273 px = pIn1;
297 <a name="l00274"></a>00274
298 <a name="l00275"></a>00275 <span class="comment">/* Working pointer of inputB */</span>
299 <a name="l00276"></a>00276 py = pIn2;
300 <a name="l00277"></a>00277
301 <a name="l00278"></a>00278 <span class="comment">/* count is index by which the pointer pIn1 to be incremented */</span>
302 <a name="l00279"></a>00279 count = 1u;
303 <a name="l00280"></a>00280
304 <a name="l00281"></a>00281 <span class="comment">/* ------------------- </span>
305 <a name="l00282"></a>00282 <span class="comment"> * Stage2 process </span>
306 <a name="l00283"></a>00283 <span class="comment"> * ------------------*/</span>
307 <a name="l00284"></a>00284
308 <a name="l00285"></a>00285 <span class="comment">/* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed. </span>
309 <a name="l00286"></a>00286 <span class="comment"> * So, to loop unroll over blockSize2, </span>
310 <a name="l00287"></a>00287 <span class="comment"> * srcBLen should be greater than or equal to 4 */</span>
311 <a name="l00288"></a>00288 <span class="keywordflow">if</span>(srcBLen >= 4u)
312 <a name="l00289"></a>00289 {
313 <a name="l00290"></a>00290 <span class="comment">/* Loop unroll over blockSize2, by 4 */</span>
314 <a name="l00291"></a>00291 blkCnt = blockSize2 >> 2u;
315 <a name="l00292"></a>00292
316 <a name="l00293"></a>00293 <span class="keywordflow">while</span>(blkCnt > 0u)
317 <a name="l00294"></a>00294 {
318 <a name="l00295"></a>00295 <span class="comment">/* Set all accumulators to zero */</span>
319 <a name="l00296"></a>00296 acc0 = 0;
320 <a name="l00297"></a>00297 acc1 = 0;
321 <a name="l00298"></a>00298 acc2 = 0;
322 <a name="l00299"></a>00299 acc3 = 0;
323 <a name="l00300"></a>00300
324 <a name="l00301"></a>00301 <span class="comment">/* read x[0], x[1], x[2] samples */</span>
325 <a name="l00302"></a>00302 x0 = *px++;
326 <a name="l00303"></a>00303 x1 = *px++;
327 <a name="l00304"></a>00304 x2 = *px++;
328 <a name="l00305"></a>00305
329 <a name="l00306"></a>00306 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
330 <a name="l00307"></a>00307 k = srcBLen >> 2u;
331 <a name="l00308"></a>00308
332 <a name="l00309"></a>00309 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
333 <a name="l00310"></a>00310 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
334 <a name="l00311"></a>00311 <span class="keywordflow">do</span>
335 <a name="l00312"></a>00312 {
336 <a name="l00313"></a>00313 <span class="comment">/* Read y[0] sample */</span>
337 <a name="l00314"></a>00314 c0 = *py++;
338 <a name="l00315"></a>00315 <span class="comment">/* Read y[1] sample */</span>
339 <a name="l00316"></a>00316 c1 = *py++;
340 <a name="l00317"></a>00317
341 <a name="l00318"></a>00318 <span class="comment">/* Read x[3] sample */</span>
342 <a name="l00319"></a>00319 x3 = *px++;
343 <a name="l00320"></a>00320
344 <a name="l00321"></a>00321 <span class="comment">/* x[0] and x[1] are packed */</span>
345 <a name="l00322"></a>00322 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x0;
346 <a name="l00323"></a>00323 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x1;
347 <a name="l00324"></a>00324
348 <a name="l00325"></a>00325 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
349 <a name="l00326"></a>00326
350 <a name="l00327"></a>00327 <span class="comment">/* y[0] and y[1] are packed */</span>
351 <a name="l00328"></a>00328 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) c0;
352 <a name="l00329"></a>00329 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) c1;
353 <a name="l00330"></a>00330
354 <a name="l00331"></a>00331 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
355 <a name="l00332"></a>00332
356 <a name="l00333"></a>00333 <span class="comment">/* acc0 += x[0] * y[0] + x[1] * y[1] */</span>
357 <a name="l00334"></a>00334 acc0 = __SMLAD(input1, input2, acc0);
358 <a name="l00335"></a>00335
359 <a name="l00336"></a>00336 <span class="comment">/* x[1] and x[2] are packed */</span>
360 <a name="l00337"></a>00337 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x1;
361 <a name="l00338"></a>00338 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x2;
362 <a name="l00339"></a>00339
363 <a name="l00340"></a>00340 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
364 <a name="l00341"></a>00341
365 <a name="l00342"></a>00342 <span class="comment">/* acc1 += x[1] * y[0] + x[2] * y[1] */</span>
366 <a name="l00343"></a>00343 acc1 = __SMLAD(input1, input2, acc1);
367 <a name="l00344"></a>00344
368 <a name="l00345"></a>00345 <span class="comment">/* x[2] and x[3] are packed */</span>
369 <a name="l00346"></a>00346 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x2;
370 <a name="l00347"></a>00347 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x3;
371 <a name="l00348"></a>00348
372 <a name="l00349"></a>00349 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
373 <a name="l00350"></a>00350
374 <a name="l00351"></a>00351 <span class="comment">/* acc2 += x[2] * y[0] + x[3] * y[1] */</span>
375 <a name="l00352"></a>00352 acc2 = __SMLAD(input1, input2, acc2);
376 <a name="l00353"></a>00353
377 <a name="l00354"></a>00354 <span class="comment">/* Read x[4] sample */</span>
378 <a name="l00355"></a>00355 x0 = *(px++);
379 <a name="l00356"></a>00356
380 <a name="l00357"></a>00357 <span class="comment">/* x[3] and x[4] are packed */</span>
381 <a name="l00358"></a>00358 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x3;
382 <a name="l00359"></a>00359 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x0;
383 <a name="l00360"></a>00360
384 <a name="l00361"></a>00361 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
385 <a name="l00362"></a>00362
386 <a name="l00363"></a>00363 <span class="comment">/* acc3 += x[3] * y[0] + x[4] * y[1] */</span>
387 <a name="l00364"></a>00364 acc3 = __SMLAD(input1, input2, acc3);
388 <a name="l00365"></a>00365
389 <a name="l00366"></a>00366 <span class="comment">/* Read y[2] sample */</span>
390 <a name="l00367"></a>00367 c0 = *py++;
391 <a name="l00368"></a>00368 <span class="comment">/* Read y[3] sample */</span>
392 <a name="l00369"></a>00369 c1 = *py++;
393 <a name="l00370"></a>00370
394 <a name="l00371"></a>00371 <span class="comment">/* Read x[5] sample */</span>
395 <a name="l00372"></a>00372 x1 = *px++;
396 <a name="l00373"></a>00373
397 <a name="l00374"></a>00374 <span class="comment">/* x[2] and x[3] are packed */</span>
398 <a name="l00375"></a>00375 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x2;
399 <a name="l00376"></a>00376 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x3;
400 <a name="l00377"></a>00377
401 <a name="l00378"></a>00378 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
402 <a name="l00379"></a>00379
403 <a name="l00380"></a>00380 <span class="comment">/* y[2] and y[3] are packed */</span>
404 <a name="l00381"></a>00381 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) c0;
405 <a name="l00382"></a>00382 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) c1;
406 <a name="l00383"></a>00383
407 <a name="l00384"></a>00384 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
408 <a name="l00385"></a>00385
409 <a name="l00386"></a>00386 <span class="comment">/* acc0 += x[2] * y[2] + x[3] * y[3] */</span>
410 <a name="l00387"></a>00387 acc0 = __SMLAD(input1, input2, acc0);
411 <a name="l00388"></a>00388
412 <a name="l00389"></a>00389 <span class="comment">/* x[3] and x[4] are packed */</span>
413 <a name="l00390"></a>00390 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x3;
414 <a name="l00391"></a>00391 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x0;
415 <a name="l00392"></a>00392
416 <a name="l00393"></a>00393 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
417 <a name="l00394"></a>00394
418 <a name="l00395"></a>00395 <span class="comment">/* acc1 += x[3] * y[2] + x[4] * y[3] */</span>
419 <a name="l00396"></a>00396 acc1 = __SMLAD(input1, input2, acc1);
420 <a name="l00397"></a>00397
421 <a name="l00398"></a>00398 <span class="comment">/* x[4] and x[5] are packed */</span>
422 <a name="l00399"></a>00399 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x0;
423 <a name="l00400"></a>00400 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x1;
424 <a name="l00401"></a>00401
425 <a name="l00402"></a>00402 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
426 <a name="l00403"></a>00403
427 <a name="l00404"></a>00404 <span class="comment">/* acc2 += x[4] * y[2] + x[5] * y[3] */</span>
428 <a name="l00405"></a>00405 acc2 = __SMLAD(input1, input2, acc2);
429 <a name="l00406"></a>00406
430 <a name="l00407"></a>00407 <span class="comment">/* Read x[6] sample */</span>
431 <a name="l00408"></a>00408 x2 = *px++;
432 <a name="l00409"></a>00409
433 <a name="l00410"></a>00410 <span class="comment">/* x[5] and x[6] are packed */</span>
434 <a name="l00411"></a>00411 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x1;
435 <a name="l00412"></a>00412 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x2;
436 <a name="l00413"></a>00413
437 <a name="l00414"></a>00414 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
438 <a name="l00415"></a>00415
439 <a name="l00416"></a>00416 <span class="comment">/* acc3 += x[5] * y[2] + x[6] * y[3] */</span>
440 <a name="l00417"></a>00417 acc3 = __SMLAD(input1, input2, acc3);
441 <a name="l00418"></a>00418
442 <a name="l00419"></a>00419 } <span class="keywordflow">while</span>(--k);
443 <a name="l00420"></a>00420
444 <a name="l00421"></a>00421 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
445 <a name="l00422"></a>00422 <span class="comment"> ** No loop unrolling is used. */</span>
446 <a name="l00423"></a>00423 k = srcBLen % 0x4u;
447 <a name="l00424"></a>00424
448 <a name="l00425"></a>00425 <span class="keywordflow">while</span>(k > 0u)
449 <a name="l00426"></a>00426 {
450 <a name="l00427"></a>00427 <span class="comment">/* Read y[4] sample */</span>
451 <a name="l00428"></a>00428 c0 = *py++;
452 <a name="l00429"></a>00429
453 <a name="l00430"></a>00430 <span class="comment">/* Read x[7] sample */</span>
454 <a name="l00431"></a>00431 x3 = *px++;
455 <a name="l00432"></a>00432
456 <a name="l00433"></a>00433 <span class="comment">/* Perform the multiply-accumulates */</span>
457 <a name="l00434"></a>00434 <span class="comment">/* acc0 += x[4] * y[4] */</span>
458 <a name="l00435"></a>00435 acc0 += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x0 * c0);
459 <a name="l00436"></a>00436 <span class="comment">/* acc1 += x[5] * y[4] */</span>
460 <a name="l00437"></a>00437 acc1 += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x1 * c0);
461 <a name="l00438"></a>00438 <span class="comment">/* acc2 += x[6] * y[4] */</span>
462 <a name="l00439"></a>00439 acc2 += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x2 * c0);
463 <a name="l00440"></a>00440 <span class="comment">/* acc3 += x[7] * y[4] */</span>
464 <a name="l00441"></a>00441 acc3 += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) x3 * c0);
465 <a name="l00442"></a>00442
466 <a name="l00443"></a>00443 <span class="comment">/* Reuse the present samples for the next MAC */</span>
467 <a name="l00444"></a>00444 x0 = x1;
468 <a name="l00445"></a>00445 x1 = x2;
469 <a name="l00446"></a>00446 x2 = x3;
470 <a name="l00447"></a>00447
471 <a name="l00448"></a>00448 <span class="comment">/* Decrement the loop counter */</span>
472 <a name="l00449"></a>00449 k--;
473 <a name="l00450"></a>00450 }
474 <a name="l00451"></a>00451
475 <a name="l00452"></a>00452 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
476 <a name="l00453"></a>00453 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(acc0 >> 7, 8));
477 <a name="l00454"></a>00454 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
478 <a name="l00455"></a>00455 pOut += inc;
479 <a name="l00456"></a>00456
480 <a name="l00457"></a>00457 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(acc1 >> 7, 8));
481 <a name="l00458"></a>00458 pOut += inc;
482 <a name="l00459"></a>00459
483 <a name="l00460"></a>00460 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(acc2 >> 7, 8));
484 <a name="l00461"></a>00461 pOut += inc;
485 <a name="l00462"></a>00462
486 <a name="l00463"></a>00463 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(acc3 >> 7, 8));
487 <a name="l00464"></a>00464 pOut += inc;
488 <a name="l00465"></a>00465
489 <a name="l00466"></a>00466 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
490 <a name="l00467"></a>00467 px = pIn1 + (count * 4u);
491 <a name="l00468"></a>00468 py = pIn2;
492 <a name="l00469"></a>00469
493 <a name="l00470"></a>00470 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
494 <a name="l00471"></a>00471 count++;
495 <a name="l00472"></a>00472
496 <a name="l00473"></a>00473 <span class="comment">/* Decrement the loop counter */</span>
497 <a name="l00474"></a>00474 blkCnt--;
498 <a name="l00475"></a>00475 }
499 <a name="l00476"></a>00476
500 <a name="l00477"></a>00477 <span class="comment">/* If the blockSize2 is not a multiple of 4, compute any remaining output samples here. </span>
501 <a name="l00478"></a>00478 <span class="comment"> ** No loop unrolling is used. */</span>
502 <a name="l00479"></a>00479 blkCnt = blockSize2 % 0x4u;
503 <a name="l00480"></a>00480
504 <a name="l00481"></a>00481 <span class="keywordflow">while</span>(blkCnt > 0u)
505 <a name="l00482"></a>00482 {
506 <a name="l00483"></a>00483 <span class="comment">/* Accumulator is made zero for every iteration */</span>
507 <a name="l00484"></a>00484 sum = 0;
508 <a name="l00485"></a>00485
509 <a name="l00486"></a>00486 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
510 <a name="l00487"></a>00487 k = srcBLen >> 2u;
511 <a name="l00488"></a>00488
512 <a name="l00489"></a>00489 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
513 <a name="l00490"></a>00490 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
514 <a name="l00491"></a>00491 <span class="keywordflow">while</span>(k > 0u)
515 <a name="l00492"></a>00492 {
516 <a name="l00493"></a>00493 <span class="comment">/* Reading two inputs of SrcA buffer and packing */</span>
517 <a name="l00494"></a>00494 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
518 <a name="l00495"></a>00495 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
519 <a name="l00496"></a>00496 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
520 <a name="l00497"></a>00497
521 <a name="l00498"></a>00498 <span class="comment">/* Reading two inputs of SrcB buffer and packing */</span>
522 <a name="l00499"></a>00499 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
523 <a name="l00500"></a>00500 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
524 <a name="l00501"></a>00501 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
525 <a name="l00502"></a>00502
526 <a name="l00503"></a>00503 <span class="comment">/* Perform the multiply-accumulates */</span>
527 <a name="l00504"></a>00504 sum = __SMLAD(input1, input2, sum);
528 <a name="l00505"></a>00505
529 <a name="l00506"></a>00506 <span class="comment">/* Reading two inputs of SrcA buffer and packing */</span>
530 <a name="l00507"></a>00507 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
531 <a name="l00508"></a>00508 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
532 <a name="l00509"></a>00509 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
533 <a name="l00510"></a>00510
534 <a name="l00511"></a>00511 <span class="comment">/* Reading two inputs of SrcB buffer and packing */</span>
535 <a name="l00512"></a>00512 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
536 <a name="l00513"></a>00513 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
537 <a name="l00514"></a>00514 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
538 <a name="l00515"></a>00515
539 <a name="l00516"></a>00516 <span class="comment">/* Perform the multiply-accumulates */</span>
540 <a name="l00517"></a>00517 sum = __SMLAD(input1, input2, sum);
541 <a name="l00518"></a>00518
542 <a name="l00519"></a>00519 <span class="comment">/* Decrement the loop counter */</span>
543 <a name="l00520"></a>00520 k--;
544 <a name="l00521"></a>00521 }
545 <a name="l00522"></a>00522
546 <a name="l00523"></a>00523 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
547 <a name="l00524"></a>00524 <span class="comment"> ** No loop unrolling is used. */</span>
548 <a name="l00525"></a>00525 k = srcBLen % 0x4u;
549 <a name="l00526"></a>00526
550 <a name="l00527"></a>00527 <span class="keywordflow">while</span>(k > 0u)
551 <a name="l00528"></a>00528 {
552 <a name="l00529"></a>00529 <span class="comment">/* Perform the multiply-accumulates */</span>
553 <a name="l00530"></a>00530 sum += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++ * *py++);
554 <a name="l00531"></a>00531
555 <a name="l00532"></a>00532 <span class="comment">/* Decrement the loop counter */</span>
556 <a name="l00533"></a>00533 k--;
557 <a name="l00534"></a>00534 }
558 <a name="l00535"></a>00535
559 <a name="l00536"></a>00536 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
560 <a name="l00537"></a>00537 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(sum >> 7, 8));
561 <a name="l00538"></a>00538 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
562 <a name="l00539"></a>00539 pOut += inc;
563 <a name="l00540"></a>00540
564 <a name="l00541"></a>00541 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
565 <a name="l00542"></a>00542 px = pIn1 + count;
566 <a name="l00543"></a>00543 py = pIn2;
567 <a name="l00544"></a>00544
568 <a name="l00545"></a>00545 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
569 <a name="l00546"></a>00546 count++;
570 <a name="l00547"></a>00547
571 <a name="l00548"></a>00548 <span class="comment">/* Decrement the loop counter */</span>
572 <a name="l00549"></a>00549 blkCnt--;
573 <a name="l00550"></a>00550 }
574 <a name="l00551"></a>00551 }
575 <a name="l00552"></a>00552 <span class="keywordflow">else</span>
576 <a name="l00553"></a>00553 {
577 <a name="l00554"></a>00554 <span class="comment">/* If the srcBLen is not a multiple of 4, </span>
578 <a name="l00555"></a>00555 <span class="comment"> * the blockSize2 loop cannot be unrolled by 4 */</span>
579 <a name="l00556"></a>00556 blkCnt = blockSize2;
580 <a name="l00557"></a>00557
581 <a name="l00558"></a>00558 <span class="keywordflow">while</span>(blkCnt > 0u)
582 <a name="l00559"></a>00559 {
583 <a name="l00560"></a>00560 <span class="comment">/* Accumulator is made zero for every iteration */</span>
584 <a name="l00561"></a>00561 sum = 0;
585 <a name="l00562"></a>00562
586 <a name="l00563"></a>00563 <span class="comment">/* Loop over srcBLen */</span>
587 <a name="l00564"></a>00564 k = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
588 <a name="l00565"></a>00565
589 <a name="l00566"></a>00566 <span class="keywordflow">while</span>(k > 0u)
590 <a name="l00567"></a>00567 {
591 <a name="l00568"></a>00568 <span class="comment">/* Perform the multiply-accumulate */</span>
592 <a name="l00569"></a>00569 sum += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++ * *py++);
593 <a name="l00570"></a>00570
594 <a name="l00571"></a>00571 <span class="comment">/* Decrement the loop counter */</span>
595 <a name="l00572"></a>00572 k--;
596 <a name="l00573"></a>00573 }
597 <a name="l00574"></a>00574
598 <a name="l00575"></a>00575 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
599 <a name="l00576"></a>00576 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(sum >> 7, 8));
600 <a name="l00577"></a>00577 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
601 <a name="l00578"></a>00578 pOut += inc;
602 <a name="l00579"></a>00579
603 <a name="l00580"></a>00580 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
604 <a name="l00581"></a>00581 px = pIn1 + count;
605 <a name="l00582"></a>00582 py = pIn2;
606 <a name="l00583"></a>00583
607 <a name="l00584"></a>00584 <span class="comment">/* Increment the MAC count */</span>
608 <a name="l00585"></a>00585 count++;
609 <a name="l00586"></a>00586
610 <a name="l00587"></a>00587 <span class="comment">/* Decrement the loop counter */</span>
611 <a name="l00588"></a>00588 blkCnt--;
612 <a name="l00589"></a>00589 }
613 <a name="l00590"></a>00590 }
614 <a name="l00591"></a>00591
615 <a name="l00592"></a>00592 <span class="comment">/* -------------------------- </span>
616 <a name="l00593"></a>00593 <span class="comment"> * Initializations of stage3 </span>
617 <a name="l00594"></a>00594 <span class="comment"> * -------------------------*/</span>
618 <a name="l00595"></a>00595
619 <a name="l00596"></a>00596 <span class="comment">/* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1] </span>
620 <a name="l00597"></a>00597 <span class="comment"> * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1] </span>
621 <a name="l00598"></a>00598 <span class="comment"> * .... </span>
622 <a name="l00599"></a>00599 <span class="comment"> * sum += x[srcALen-2] * y[0] + x[srcALen-1] * y[1] </span>
623 <a name="l00600"></a>00600 <span class="comment"> * sum += x[srcALen-1] * y[0] </span>
624 <a name="l00601"></a>00601 <span class="comment"> */</span>
625 <a name="l00602"></a>00602
626 <a name="l00603"></a>00603 <span class="comment">/* In this stage the MAC operations are decreased by 1 for every iteration. </span>
627 <a name="l00604"></a>00604 <span class="comment"> The count variable holds the number of MAC operations performed */</span>
628 <a name="l00605"></a>00605 count = srcBLen - 1u;
629 <a name="l00606"></a>00606
630 <a name="l00607"></a>00607 <span class="comment">/* Working pointer of inputA */</span>
631 <a name="l00608"></a>00608 pSrc1 = pIn1 + (srcALen - (srcBLen - 1u));
632 <a name="l00609"></a>00609 px = pSrc1;
633 <a name="l00610"></a>00610
634 <a name="l00611"></a>00611 <span class="comment">/* Working pointer of inputB */</span>
635 <a name="l00612"></a>00612 py = pIn2;
636 <a name="l00613"></a>00613
637 <a name="l00614"></a>00614 <span class="comment">/* ------------------- </span>
638 <a name="l00615"></a>00615 <span class="comment"> * Stage3 process </span>
639 <a name="l00616"></a>00616 <span class="comment"> * ------------------*/</span>
640 <a name="l00617"></a>00617
641 <a name="l00618"></a>00618 <span class="keywordflow">while</span>(blockSize3 > 0u)
642 <a name="l00619"></a>00619 {
643 <a name="l00620"></a>00620 <span class="comment">/* Accumulator is made zero for every iteration */</span>
644 <a name="l00621"></a>00621 sum = 0;
645 <a name="l00622"></a>00622
646 <a name="l00623"></a>00623 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
647 <a name="l00624"></a>00624 k = count >> 2u;
648 <a name="l00625"></a>00625
649 <a name="l00626"></a>00626 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
650 <a name="l00627"></a>00627 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
651 <a name="l00628"></a>00628 <span class="keywordflow">while</span>(k > 0u)
652 <a name="l00629"></a>00629 {
653 <a name="l00630"></a>00630 <span class="comment">/* x[srcALen - srcBLen + 1] , x[srcALen - srcBLen + 2] */</span>
654 <a name="l00631"></a>00631 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
655 <a name="l00632"></a>00632 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
656 <a name="l00633"></a>00633 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
657 <a name="l00634"></a>00634
658 <a name="l00635"></a>00635 <span class="comment">/* y[0] , y[1] */</span>
659 <a name="l00636"></a>00636 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
660 <a name="l00637"></a>00637 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
661 <a name="l00638"></a>00638 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
662 <a name="l00639"></a>00639
663 <a name="l00640"></a>00640 <span class="comment">/* sum += x[srcALen - srcBLen + 1] * y[0] */</span>
664 <a name="l00641"></a>00641 <span class="comment">/* sum += x[srcALen - srcBLen + 2] * y[1] */</span>
665 <a name="l00642"></a>00642 sum = __SMLAD(input1, input2, sum);
666 <a name="l00643"></a>00643
667 <a name="l00644"></a>00644 <span class="comment">/* x[srcALen - srcBLen + 3] , x[srcALen - srcBLen + 4] */</span>
668 <a name="l00645"></a>00645 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
669 <a name="l00646"></a>00646 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++;
670 <a name="l00647"></a>00647 input1 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
671 <a name="l00648"></a>00648
672 <a name="l00649"></a>00649 <span class="comment">/* y[2] , y[3] */</span>
673 <a name="l00650"></a>00650 in1 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
674 <a name="l00651"></a>00651 in2 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * py++;
675 <a name="l00652"></a>00652 input2 = ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in1 & 0x0000FFFF) | ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) in2 << 16);
676 <a name="l00653"></a>00653
677 <a name="l00654"></a>00654 <span class="comment">/* sum += x[srcALen - srcBLen + 3] * y[2] */</span>
678 <a name="l00655"></a>00655 <span class="comment">/* sum += x[srcALen - srcBLen + 4] * y[3] */</span>
679 <a name="l00656"></a>00656 sum = __SMLAD(input1, input2, sum);
680 <a name="l00657"></a>00657
681 <a name="l00658"></a>00658 <span class="comment">/* Decrement the loop counter */</span>
682 <a name="l00659"></a>00659 k--;
683 <a name="l00660"></a>00660 }
684 <a name="l00661"></a>00661
685 <a name="l00662"></a>00662 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
686 <a name="l00663"></a>00663 <span class="comment"> ** No loop unrolling is used. */</span>
687 <a name="l00664"></a>00664 k = count % 0x4u;
688 <a name="l00665"></a>00665
689 <a name="l00666"></a>00666 <span class="keywordflow">while</span>(k > 0u)
690 <a name="l00667"></a>00667 {
691 <a name="l00668"></a>00668 <span class="comment">/* Perform the multiply-accumulates */</span>
692 <a name="l00669"></a>00669 sum += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) * px++ * *py++);
693 <a name="l00670"></a>00670
694 <a name="l00671"></a>00671 <span class="comment">/* Decrement the loop counter */</span>
695 <a name="l00672"></a>00672 k--;
696 <a name="l00673"></a>00673 }
697 <a name="l00674"></a>00674
698 <a name="l00675"></a>00675 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
699 <a name="l00676"></a>00676 *pOut = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) (__SSAT(sum >> 7, 8));
700 <a name="l00677"></a>00677 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
701 <a name="l00678"></a>00678 pOut += inc;
702 <a name="l00679"></a>00679
703 <a name="l00680"></a>00680 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
704 <a name="l00681"></a>00681 px = ++pSrc1;
705 <a name="l00682"></a>00682 py = pIn2;
706 <a name="l00683"></a>00683
707 <a name="l00684"></a>00684 <span class="comment">/* Decrement the MAC count */</span>
708 <a name="l00685"></a>00685 count--;
709 <a name="l00686"></a>00686
710 <a name="l00687"></a>00687 <span class="comment">/* Decrement the loop counter */</span>
711 <a name="l00688"></a>00688 blockSize3--;
712 <a name="l00689"></a>00689 }
713 <a name="l00690"></a>00690
714 <a name="l00691"></a>00691 <span class="preprocessor">#else</span>
715 <a name="l00692"></a>00692 <span class="preprocessor"></span>
716 <a name="l00693"></a>00693 <span class="comment">/* Run the below code for Cortex-M0 */</span>
717 <a name="l00694"></a>00694
718 <a name="l00695"></a>00695 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *pIn1 = pSrcA; <span class="comment">/* inputA pointer */</span>
719 <a name="l00696"></a>00696 <a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a> *pIn2 = pSrcB + (srcBLen - 1u); <span class="comment">/* inputB pointer */</span>
720 <a name="l00697"></a>00697 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> sum; <span class="comment">/* Accumulator */</span>
721 <a name="l00698"></a>00698 uint32_t i = 0u, j; <span class="comment">/* loop counters */</span>
722 <a name="l00699"></a>00699 uint32_t inv = 0u; <span class="comment">/* Reverse order flag */</span>
723 <a name="l00700"></a>00700 uint32_t tot = 0u; <span class="comment">/* Length */</span>
724 <a name="l00701"></a>00701
725 <a name="l00702"></a>00702 <span class="comment">/* The algorithm implementation is based on the lengths of the inputs. */</span>
726 <a name="l00703"></a>00703 <span class="comment">/* srcB is always made to slide across srcA. */</span>
727 <a name="l00704"></a>00704 <span class="comment">/* So srcBLen is always considered as shorter or equal to srcALen */</span>
728 <a name="l00705"></a>00705 <span class="comment">/* But CORR(x, y) is reverse of CORR(y, x) */</span>
729 <a name="l00706"></a>00706 <span class="comment">/* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */</span>
730 <a name="l00707"></a>00707 <span class="comment">/* and a varaible, inv is set to 1 */</span>
731 <a name="l00708"></a>00708 <span class="comment">/* If lengths are not equal then zero pad has to be done to make the two </span>
732 <a name="l00709"></a>00709 <span class="comment"> * inputs of same length. But to improve the performance, we include zeroes </span>
733 <a name="l00710"></a>00710 <span class="comment"> * in the output instead of zero padding either of the the inputs*/</span>
734 <a name="l00711"></a>00711 <span class="comment">/* If srcALen > srcBLen, (srcALen - srcBLen) zeroes has to included in the </span>
735 <a name="l00712"></a>00712 <span class="comment"> * starting of the output buffer */</span>
736 <a name="l00713"></a>00713 <span class="comment">/* If srcALen < srcBLen, (srcALen - srcBLen) zeroes has to included in the </span>
737 <a name="l00714"></a>00714 <span class="comment"> * ending of the output buffer */</span>
738 <a name="l00715"></a>00715 <span class="comment">/* Once the zero padding is done the remaining of the output is calcualted </span>
739 <a name="l00716"></a>00716 <span class="comment"> * using convolution but with the shorter signal time shifted. */</span>
740 <a name="l00717"></a>00717
741 <a name="l00718"></a>00718 <span class="comment">/* Calculate the length of the remaining sequence */</span>
742 <a name="l00719"></a>00719 tot = ((srcALen + <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>) - 2u);
743 <a name="l00720"></a>00720
744 <a name="l00721"></a>00721 <span class="keywordflow">if</span>(srcALen > srcBLen)
745 <a name="l00722"></a>00722 {
746 <a name="l00723"></a>00723 <span class="comment">/* Calculating the number of zeros to be padded to the output */</span>
747 <a name="l00724"></a>00724 j = srcALen - <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
748 <a name="l00725"></a>00725
749 <a name="l00726"></a>00726 <span class="comment">/* Initialise the pointer after zero padding */</span>
750 <a name="l00727"></a>00727 pDst += j;
751 <a name="l00728"></a>00728 }
752 <a name="l00729"></a>00729
753 <a name="l00730"></a>00730 <span class="keywordflow">else</span> <span class="keywordflow">if</span>(srcALen < srcBLen)
754 <a name="l00731"></a>00731 {
755 <a name="l00732"></a>00732 <span class="comment">/* Initialization to inputB pointer */</span>
756 <a name="l00733"></a>00733 pIn1 = pSrcB;
757 <a name="l00734"></a>00734
758 <a name="l00735"></a>00735 <span class="comment">/* Initialization to the end of inputA pointer */</span>
759 <a name="l00736"></a>00736 pIn2 = pSrcA + (srcALen - 1u);
760 <a name="l00737"></a>00737
761 <a name="l00738"></a>00738 <span class="comment">/* Initialisation of the pointer after zero padding */</span>
762 <a name="l00739"></a>00739 pDst = pDst + tot;
763 <a name="l00740"></a>00740
764 <a name="l00741"></a>00741 <span class="comment">/* Swapping the lengths */</span>
765 <a name="l00742"></a>00742 j = <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>;
766 <a name="l00743"></a>00743 srcALen = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
767 <a name="l00744"></a>00744 srcBLen = j;
768 <a name="l00745"></a>00745
769 <a name="l00746"></a>00746 <span class="comment">/* Setting the reverse flag */</span>
770 <a name="l00747"></a>00747 inv = 1;
771 <a name="l00748"></a>00748
772 <a name="l00749"></a>00749 }
773 <a name="l00750"></a>00750
774 <a name="l00751"></a>00751 <span class="comment">/* Loop to calculate convolution for output length number of times */</span>
775 <a name="l00752"></a>00752 <span class="keywordflow">for</span> (i = 0u; i <= tot; i++)
776 <a name="l00753"></a>00753 {
777 <a name="l00754"></a>00754 <span class="comment">/* Initialize sum with zero to carry on MAC operations */</span>
778 <a name="l00755"></a>00755 sum = 0;
779 <a name="l00756"></a>00756
780 <a name="l00757"></a>00757 <span class="comment">/* Loop to perform MAC operations according to convolution equation */</span>
781 <a name="l00758"></a>00758 <span class="keywordflow">for</span> (j = 0u; j <= i; j++)
782 <a name="l00759"></a>00759 {
783 <a name="l00760"></a>00760 <span class="comment">/* Check the array limitations */</span>
784 <a name="l00761"></a>00761 <span class="keywordflow">if</span>((((i - j) < <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>) && (j < srcALen)))
785 <a name="l00762"></a>00762 {
786 <a name="l00763"></a>00763 <span class="comment">/* z[i] += x[i-j] * y[j] */</span>
787 <a name="l00764"></a>00764 sum += ((<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) pIn1[j] * pIn2[-((int32_t) i - j)]);
788 <a name="l00765"></a>00765 }
789 <a name="l00766"></a>00766 }
790 <a name="l00767"></a>00767 <span class="comment">/* Store the output in the destination buffer */</span>
791 <a name="l00768"></a>00768 <span class="keywordflow">if</span>(inv == 1)
792 <a name="l00769"></a>00769 *pDst-- = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) __SSAT((sum >> 7u), 8u);
793 <a name="l00770"></a>00770 <span class="keywordflow">else</span>
794 <a name="l00771"></a>00771 *pDst++ = (<a class="code" href="arm__math_8h.html#ae541b6f232c305361e9b416fc9eed263" title="8-bit fractional data type in 1.7 format.">q7_t</a>) __SSAT((sum >> 7u), 8u);
795 <a name="l00772"></a>00772 }
796 <a name="l00773"></a>00773
797 <a name="l00774"></a>00774 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_CM0 */</span>
798 <a name="l00775"></a>00775
799 <a name="l00776"></a>00776 }
800 <a name="l00777"></a>00777
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