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<h1>arm_conv_q15.c</h1> </div>
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<a href="arm__conv__q15_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>
<a name="l00002"></a>00002 <span class="comment">* Copyright (C) 2010 ARM Limited. All rights reserved. </span>
<a name="l00003"></a>00003 <span class="comment">* </span>
<a name="l00004"></a>00004 <span class="comment">* $Date: 15. July 2011 </span>
<a name="l00005"></a>00005 <span class="comment">* $Revision: V1.0.10 </span>
<a name="l00006"></a>00006 <span class="comment">* </span>
<a name="l00007"></a>00007 <span class="comment">* Project: CMSIS DSP Library </span>
<a name="l00008"></a>00008 <span class="comment">* Title: arm_conv_q15.c </span>
<a name="l00009"></a>00009 <span class="comment">* </span>
<a name="l00010"></a>00010 <span class="comment">* Description: Convolution of Q15 sequences. </span>
<a name="l00011"></a>00011 <span class="comment">* </span>
<a name="l00012"></a>00012 <span class="comment">* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0</span>
<a name="l00013"></a>00013 <span class="comment">* </span>
<a name="l00014"></a>00014 <span class="comment">* Version 1.0.10 2011/7/15 </span>
<a name="l00015"></a>00015 <span class="comment">* Big Endian support added and Merged M0 and M3/M4 Source code. </span>
<a name="l00016"></a>00016 <span class="comment">* </span>
<a name="l00017"></a>00017 <span class="comment">* Version 1.0.3 2010/11/29 </span>
<a name="l00018"></a>00018 <span class="comment">* Re-organized the CMSIS folders and updated documentation. </span>
<a name="l00019"></a>00019 <span class="comment">* </span>
<a name="l00020"></a>00020 <span class="comment">* Version 1.0.2 2010/11/11 </span>
<a name="l00021"></a>00021 <span class="comment">* Documentation updated. </span>
<a name="l00022"></a>00022 <span class="comment">* </span>
<a name="l00023"></a>00023 <span class="comment">* Version 1.0.1 2010/10/05 </span>
<a name="l00024"></a>00024 <span class="comment">* Production release and review comments incorporated. </span>
<a name="l00025"></a>00025 <span class="comment">* </span>
<a name="l00026"></a>00026 <span class="comment">* Version 1.0.0 2010/09/20 </span>
<a name="l00027"></a>00027 <span class="comment">* Production release and review comments incorporated </span>
<a name="l00028"></a>00028 <span class="comment">* </span>
<a name="l00029"></a>00029 <span class="comment">* Version 0.0.7 2010/06/10 </span>
<a name="l00030"></a>00030 <span class="comment">* Misra-C changes done </span>
<a name="l00031"></a>00031 <span class="comment">* </span>
<a name="l00032"></a>00032 <span class="comment">* -------------------------------------------------------------------- */</span>
<a name="l00033"></a>00033
<a name="l00034"></a>00034 <span class="preprocessor">#include &quot;<a class="code" href="arm__math_8h.html">arm_math.h</a>&quot;</span>
<a name="l00035"></a>00035
<a name="l00068"></a><a class="code" href="group___conv.html#gaccd6a89b0ff7a94df64610598e6e6893">00068</a> <span class="keywordtype">void</span> <a class="code" href="group___conv.html#gaccd6a89b0ff7a94df64610598e6e6893" title="Convolution of Q15 sequences.">arm_conv_q15</a>(
<a name="l00069"></a>00069 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> * pSrcA,
<a name="l00070"></a>00070 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>,
<a name="l00071"></a>00071 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> * pSrcB,
<a name="l00072"></a>00072 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>,
<a name="l00073"></a>00073 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> * pDst)
<a name="l00074"></a>00074 {
<a name="l00075"></a>00075
<a name="l00076"></a>00076 <span class="preprocessor">#ifndef ARM_MATH_CM0</span>
<a name="l00077"></a>00077 <span class="preprocessor"></span>
<a name="l00078"></a>00078 <span class="comment">/* Run the below code for Cortex-M4 and Cortex-M3 */</span>
<a name="l00079"></a>00079
<a name="l00080"></a>00080 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *pIn1; <span class="comment">/* inputA pointer */</span>
<a name="l00081"></a>00081 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *pIn2; <span class="comment">/* inputB pointer */</span>
<a name="l00082"></a>00082 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *pOut = pDst; <span class="comment">/* output pointer */</span>
<a name="l00083"></a>00083 <a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a> sum, acc0, acc1, acc2, acc3; <span class="comment">/* Accumulator */</span>
<a name="l00084"></a>00084 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *px; <span class="comment">/* Intermediate inputA pointer */</span>
<a name="l00085"></a>00085 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *py; <span class="comment">/* Intermediate inputB pointer */</span>
<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> *pSrc1, *pSrc2; <span class="comment">/* Intermediate pointers */</span>
<a name="l00087"></a>00087 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> x0, x1, x2, x3, c0; <span class="comment">/* Temporary variables to hold state and coefficient values */</span>
<a name="l00088"></a>00088 uint32_t blockSize1, blockSize2, blockSize3, j, k, count, blkCnt; <span class="comment">/* loop counter */</span>
<a name="l00089"></a>00089 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pb; <span class="comment">/* 32 bit pointer for inputB buffer */</span>
<a name="l00090"></a>00090
<a name="l00091"></a>00091
<a name="l00092"></a>00092 <span class="comment">/* The algorithm implementation is based on the lengths of the inputs. */</span>
<a name="l00093"></a>00093 <span class="comment">/* srcB is always made to slide across srcA. */</span>
<a name="l00094"></a>00094 <span class="comment">/* So srcBLen is always considered as shorter or equal to srcALen */</span>
<a name="l00095"></a>00095 <span class="keywordflow">if</span>(srcALen &gt;= srcBLen)
<a name="l00096"></a>00096 {
<a name="l00097"></a>00097 <span class="comment">/* Initialization of inputA pointer */</span>
<a name="l00098"></a>00098 pIn1 = pSrcA;
<a name="l00099"></a>00099
<a name="l00100"></a>00100 <span class="comment">/* Initialization of inputB pointer */</span>
<a name="l00101"></a>00101 pIn2 = pSrcB;
<a name="l00102"></a>00102 }
<a name="l00103"></a>00103 <span class="keywordflow">else</span>
<a name="l00104"></a>00104 {
<a name="l00105"></a>00105 <span class="comment">/* Initialization of inputA pointer */</span>
<a name="l00106"></a>00106 pIn1 = pSrcB;
<a name="l00107"></a>00107
<a name="l00108"></a>00108 <span class="comment">/* Initialization of inputB pointer */</span>
<a name="l00109"></a>00109 pIn2 = pSrcA;
<a name="l00110"></a>00110
<a name="l00111"></a>00111 <span class="comment">/* srcBLen is always considered as shorter or equal to srcALen */</span>
<a name="l00112"></a>00112 j = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
<a name="l00113"></a>00113 srcBLen = <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>;
<a name="l00114"></a>00114 srcALen = j;
<a name="l00115"></a>00115 }
<a name="l00116"></a>00116
<a name="l00117"></a>00117 <span class="comment">/* conv(x,y) at n = x[n] * y[0] + x[n-1] * y[1] + x[n-2] * y[2] + ...+ x[n-N+1] * y[N -1] */</span>
<a name="l00118"></a>00118 <span class="comment">/* The function is internally </span>
<a name="l00119"></a>00119 <span class="comment"> * divided into three stages according to the number of multiplications that has to be </span>
<a name="l00120"></a>00120 <span class="comment"> * taken place between inputA samples and inputB samples. In the first stage of the </span>
<a name="l00121"></a>00121 <span class="comment"> * algorithm, the multiplications increase by one for every iteration. </span>
<a name="l00122"></a>00122 <span class="comment"> * In the second stage of the algorithm, srcBLen number of multiplications are done. </span>
<a name="l00123"></a>00123 <span class="comment"> * In the third stage of the algorithm, the multiplications decrease by one </span>
<a name="l00124"></a>00124 <span class="comment"> * for every iteration. */</span>
<a name="l00125"></a>00125
<a name="l00126"></a>00126 <span class="comment">/* The algorithm is implemented in three stages. </span>
<a name="l00127"></a>00127 <span class="comment"> The loop counters of each stage is initiated here. */</span>
<a name="l00128"></a>00128 blockSize1 = srcBLen - 1u;
<a name="l00129"></a>00129 blockSize2 = srcALen - (srcBLen - 1u);
<a name="l00130"></a>00130
<a name="l00131"></a>00131 <span class="comment">/* -------------------------- </span>
<a name="l00132"></a>00132 <span class="comment"> * Initializations of stage1 </span>
<a name="l00133"></a>00133 <span class="comment"> * -------------------------*/</span>
<a name="l00134"></a>00134
<a name="l00135"></a>00135 <span class="comment">/* sum = x[0] * y[0] </span>
<a name="l00136"></a>00136 <span class="comment"> * sum = x[0] * y[1] + x[1] * y[0] </span>
<a name="l00137"></a>00137 <span class="comment"> * .... </span>
<a name="l00138"></a>00138 <span class="comment"> * sum = x[0] * y[srcBlen - 1] + x[1] * y[srcBlen - 2] +...+ x[srcBLen - 1] * y[0] </span>
<a name="l00139"></a>00139 <span class="comment"> */</span>
<a name="l00140"></a>00140
<a name="l00141"></a>00141 <span class="comment">/* In this stage the MAC operations are increased by 1 for every iteration. </span>
<a name="l00142"></a>00142 <span class="comment"> The count variable holds the number of MAC operations performed */</span>
<a name="l00143"></a>00143 count = 1u;
<a name="l00144"></a>00144
<a name="l00145"></a>00145 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00146"></a>00146 px = pIn1;
<a name="l00147"></a>00147
<a name="l00148"></a>00148 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00149"></a>00149 py = pIn2;
<a name="l00150"></a>00150
<a name="l00151"></a>00151
<a name="l00152"></a>00152 <span class="comment">/* ------------------------ </span>
<a name="l00153"></a>00153 <span class="comment"> * Stage1 process </span>
<a name="l00154"></a>00154 <span class="comment"> * ----------------------*/</span>
<a name="l00155"></a>00155
<a name="l00156"></a>00156 <span class="comment">/* For loop unrolling by 4, this stage is divided into two. */</span>
<a name="l00157"></a>00157 <span class="comment">/* First part of this stage computes the MAC operations less than 4 */</span>
<a name="l00158"></a>00158 <span class="comment">/* Second part of this stage computes the MAC operations greater than or equal to 4 */</span>
<a name="l00159"></a>00159
<a name="l00160"></a>00160 <span class="comment">/* The first part of the stage starts here */</span>
<a name="l00161"></a>00161 <span class="keywordflow">while</span>((count &lt; 4u) &amp;&amp; (blockSize1 &gt; 0u))
<a name="l00162"></a>00162 {
<a name="l00163"></a>00163 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00164"></a>00164 sum = 0;
<a name="l00165"></a>00165
<a name="l00166"></a>00166 <span class="comment">/* Loop over number of MAC operations between </span>
<a name="l00167"></a>00167 <span class="comment"> * inputA samples and inputB samples */</span>
<a name="l00168"></a>00168 k = count;
<a name="l00169"></a>00169
<a name="l00170"></a>00170 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00171"></a>00171 {
<a name="l00172"></a>00172 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00173"></a>00173 sum = __SMLALD(*px++, *py--, sum);
<a name="l00174"></a>00174
<a name="l00175"></a>00175 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00176"></a>00176 k--;
<a name="l00177"></a>00177 }
<a name="l00178"></a>00178
<a name="l00179"></a>00179 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00180"></a>00180 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (__SSAT((sum &gt;&gt; 15), 16));
<a name="l00181"></a>00181
<a name="l00182"></a>00182 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00183"></a>00183 py = pIn2 + count;
<a name="l00184"></a>00184 px = pIn1;
<a name="l00185"></a>00185
<a name="l00186"></a>00186 <span class="comment">/* Increment the MAC count */</span>
<a name="l00187"></a>00187 count++;
<a name="l00188"></a>00188
<a name="l00189"></a>00189 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00190"></a>00190 blockSize1--;
<a name="l00191"></a>00191 }
<a name="l00192"></a>00192
<a name="l00193"></a>00193 <span class="comment">/* The second part of the stage starts here */</span>
<a name="l00194"></a>00194 <span class="comment">/* The internal loop, over count, is unrolled by 4 */</span>
<a name="l00195"></a>00195 <span class="comment">/* To, read the last two inputB samples using SIMD: </span>
<a name="l00196"></a>00196 <span class="comment"> * y[srcBLen] and y[srcBLen-1] coefficients, py is decremented by 1 */</span>
<a name="l00197"></a>00197 py = py - 1;
<a name="l00198"></a>00198
<a name="l00199"></a>00199 <span class="keywordflow">while</span>(blockSize1 &gt; 0u)
<a name="l00200"></a>00200 {
<a name="l00201"></a>00201 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00202"></a>00202 sum = 0;
<a name="l00203"></a>00203
<a name="l00204"></a>00204 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00205"></a>00205 k = count &gt;&gt; 2u;
<a name="l00206"></a>00206
<a name="l00207"></a>00207 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00208"></a>00208 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00209"></a>00209 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00210"></a>00210 {
<a name="l00211"></a>00211 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00212"></a>00212 <span class="comment">/* x[0], x[1] are multiplied with y[srcBLen - 1], y[srcBLen - 2] respectively */</span>
<a name="l00213"></a>00213 sum = __SMLALDX(*<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(px)++, *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(py)--, sum);
<a name="l00214"></a>00214 <span class="comment">/* x[2], x[3] are multiplied with y[srcBLen - 3], y[srcBLen - 4] respectively */</span>
<a name="l00215"></a>00215 sum = __SMLALDX(*<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(px)++, *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(py)--, sum);
<a name="l00216"></a>00216
<a name="l00217"></a>00217 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00218"></a>00218 k--;
<a name="l00219"></a>00219 }
<a name="l00220"></a>00220
<a name="l00221"></a>00221 <span class="comment">/* For the next MAC operations, the pointer py is used without SIMD </span>
<a name="l00222"></a>00222 <span class="comment"> * So, py is incremented by 1 */</span>
<a name="l00223"></a>00223 py = py + 1u;
<a name="l00224"></a>00224
<a name="l00225"></a>00225 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00226"></a>00226 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00227"></a>00227 k = count % 0x4u;
<a name="l00228"></a>00228
<a name="l00229"></a>00229 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00230"></a>00230 {
<a name="l00231"></a>00231 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00232"></a>00232 sum = __SMLALD(*px++, *py--, sum);
<a name="l00233"></a>00233
<a name="l00234"></a>00234 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00235"></a>00235 k--;
<a name="l00236"></a>00236 }
<a name="l00237"></a>00237
<a name="l00238"></a>00238 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00239"></a>00239 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (__SSAT((sum &gt;&gt; 15), 16));
<a name="l00240"></a>00240
<a name="l00241"></a>00241 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00242"></a>00242 py = pIn2 + (count - 1u);
<a name="l00243"></a>00243 px = pIn1;
<a name="l00244"></a>00244
<a name="l00245"></a>00245 <span class="comment">/* Increment the MAC count */</span>
<a name="l00246"></a>00246 count++;
<a name="l00247"></a>00247
<a name="l00248"></a>00248 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00249"></a>00249 blockSize1--;
<a name="l00250"></a>00250 }
<a name="l00251"></a>00251
<a name="l00252"></a>00252 <span class="comment">/* -------------------------- </span>
<a name="l00253"></a>00253 <span class="comment"> * Initializations of stage2 </span>
<a name="l00254"></a>00254 <span class="comment"> * ------------------------*/</span>
<a name="l00255"></a>00255
<a name="l00256"></a>00256 <span class="comment">/* sum = x[0] * y[srcBLen-1] + x[1] * y[srcBLen-2] +...+ x[srcBLen-1] * y[0] </span>
<a name="l00257"></a>00257 <span class="comment"> * sum = x[1] * y[srcBLen-1] + x[2] * y[srcBLen-2] +...+ x[srcBLen] * y[0] </span>
<a name="l00258"></a>00258 <span class="comment"> * .... </span>
<a name="l00259"></a>00259 <span class="comment"> * sum = x[srcALen-srcBLen-2] * y[srcBLen-1] + x[srcALen] * y[srcBLen-2] +...+ x[srcALen-1] * y[0] </span>
<a name="l00260"></a>00260 <span class="comment"> */</span>
<a name="l00261"></a>00261
<a name="l00262"></a>00262 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00263"></a>00263 px = pIn1;
<a name="l00264"></a>00264
<a name="l00265"></a>00265 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00266"></a>00266 pSrc2 = pIn2 + (srcBLen - 1u);
<a name="l00267"></a>00267 py = pSrc2;
<a name="l00268"></a>00268
<a name="l00269"></a>00269 <span class="comment">/* Initialize inputB pointer of type q31 */</span>
<a name="l00270"></a>00270 pb = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (py - 1u);
<a name="l00271"></a>00271
<a name="l00272"></a>00272 <span class="comment">/* count is the index by which the pointer pIn1 to be incremented */</span>
<a name="l00273"></a>00273 count = 1u;
<a name="l00274"></a>00274
<a name="l00275"></a>00275
<a name="l00276"></a>00276 <span class="comment">/* -------------------- </span>
<a name="l00277"></a>00277 <span class="comment"> * Stage2 process </span>
<a name="l00278"></a>00278 <span class="comment"> * -------------------*/</span>
<a name="l00279"></a>00279
<a name="l00280"></a>00280 <span class="comment">/* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed. </span>
<a name="l00281"></a>00281 <span class="comment"> * So, to loop unroll over blockSize2, </span>
<a name="l00282"></a>00282 <span class="comment"> * srcBLen should be greater than or equal to 4 */</span>
<a name="l00283"></a>00283 <span class="keywordflow">if</span>(srcBLen &gt;= 4u)
<a name="l00284"></a>00284 {
<a name="l00285"></a>00285 <span class="comment">/* Loop unroll over blockSize2, by 4 */</span>
<a name="l00286"></a>00286 blkCnt = blockSize2 &gt;&gt; 2u;
<a name="l00287"></a>00287
<a name="l00288"></a>00288 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00289"></a>00289 {
<a name="l00290"></a>00290 <span class="comment">/* Set all accumulators to zero */</span>
<a name="l00291"></a>00291 acc0 = 0;
<a name="l00292"></a>00292 acc1 = 0;
<a name="l00293"></a>00293 acc2 = 0;
<a name="l00294"></a>00294 acc3 = 0;
<a name="l00295"></a>00295
<a name="l00296"></a>00296
<a name="l00297"></a>00297 <span class="comment">/* read x[0], x[1] samples */</span>
<a name="l00298"></a>00298 x0 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (px++);
<a name="l00299"></a>00299 <span class="comment">/* read x[1], x[2] samples */</span>
<a name="l00300"></a>00300 x1 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (px++);
<a name="l00301"></a>00301
<a name="l00302"></a>00302
<a name="l00303"></a>00303 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00304"></a>00304 k = srcBLen &gt;&gt; 2u;
<a name="l00305"></a>00305
<a name="l00306"></a>00306 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00307"></a>00307 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00308"></a>00308 <span class="keywordflow">do</span>
<a name="l00309"></a>00309 {
<a name="l00310"></a>00310 <span class="comment">/* Read the last two inputB samples using SIMD: </span>
<a name="l00311"></a>00311 <span class="comment"> * y[srcBLen - 1] and y[srcBLen - 2] */</span>
<a name="l00312"></a>00312 c0 = *(pb--);
<a name="l00313"></a>00313
<a name="l00314"></a>00314 <span class="comment">/* acc0 += x[0] * y[srcBLen - 1] + x[1] * y[srcBLen - 2] */</span>
<a name="l00315"></a>00315 acc0 = __SMLALDX(x0, c0, acc0);
<a name="l00316"></a>00316
<a name="l00317"></a>00317 <span class="comment">/* acc1 += x[1] * y[srcBLen - 1] + x[2] * y[srcBLen - 2] */</span>
<a name="l00318"></a>00318 acc1 = __SMLALDX(x1, c0, acc1);
<a name="l00319"></a>00319
<a name="l00320"></a>00320 <span class="comment">/* Read x[2], x[3] */</span>
<a name="l00321"></a>00321 x2 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (px++);
<a name="l00322"></a>00322
<a name="l00323"></a>00323 <span class="comment">/* Read x[3], x[4] */</span>
<a name="l00324"></a>00324 x3 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (px++);
<a name="l00325"></a>00325
<a name="l00326"></a>00326 <span class="comment">/* acc2 += x[2] * y[srcBLen - 1] + x[3] * y[srcBLen - 2] */</span>
<a name="l00327"></a>00327 acc2 = __SMLALDX(x2, c0, acc2);
<a name="l00328"></a>00328
<a name="l00329"></a>00329 <span class="comment">/* acc3 += x[3] * y[srcBLen - 1] + x[4] * y[srcBLen - 2] */</span>
<a name="l00330"></a>00330 acc3 = __SMLALDX(x3, c0, acc3);
<a name="l00331"></a>00331
<a name="l00332"></a>00332 <span class="comment">/* Read y[srcBLen - 3] and y[srcBLen - 4] */</span>
<a name="l00333"></a>00333 c0 = *(pb--);
<a name="l00334"></a>00334
<a name="l00335"></a>00335 <span class="comment">/* acc0 += x[2] * y[srcBLen - 3] + x[3] * y[srcBLen - 4] */</span>
<a name="l00336"></a>00336 acc0 = __SMLALDX(x2, c0, acc0);
<a name="l00337"></a>00337
<a name="l00338"></a>00338 <span class="comment">/* acc1 += x[3] * y[srcBLen - 3] + x[4] * y[srcBLen - 4] */</span>
<a name="l00339"></a>00339 acc1 = __SMLALDX(x3, c0, acc1);
<a name="l00340"></a>00340
<a name="l00341"></a>00341 <span class="comment">/* Read x[4], x[5] */</span>
<a name="l00342"></a>00342 x0 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (px++);
<a name="l00343"></a>00343
<a name="l00344"></a>00344 <span class="comment">/* Read x[5], x[6] */</span>
<a name="l00345"></a>00345 x1 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (px++);
<a name="l00346"></a>00346
<a name="l00347"></a>00347 <span class="comment">/* acc2 += x[4] * y[srcBLen - 3] + x[5] * y[srcBLen - 4] */</span>
<a name="l00348"></a>00348 acc2 = __SMLALDX(x0, c0, acc2);
<a name="l00349"></a>00349
<a name="l00350"></a>00350 <span class="comment">/* acc3 += x[5] * y[srcBLen - 3] + x[6] * y[srcBLen - 4] */</span>
<a name="l00351"></a>00351 acc3 = __SMLALDX(x1, c0, acc3);
<a name="l00352"></a>00352
<a name="l00353"></a>00353 } <span class="keywordflow">while</span>(--k);
<a name="l00354"></a>00354
<a name="l00355"></a>00355 <span class="comment">/* For the next MAC operations, SIMD is not used </span>
<a name="l00356"></a>00356 <span class="comment"> * So, the 16 bit pointer if inputB, py is updated */</span>
<a name="l00357"></a>00357 py = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *) pb;
<a name="l00358"></a>00358 py = py + 1;
<a name="l00359"></a>00359
<a name="l00360"></a>00360 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00361"></a>00361 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00362"></a>00362 k = srcBLen % 0x4u;
<a name="l00363"></a>00363
<a name="l00364"></a>00364 <span class="keywordflow">if</span>(k == 1u)
<a name="l00365"></a>00365 {
<a name="l00366"></a>00366 <span class="comment">/* Read y[srcBLen - 5] */</span>
<a name="l00367"></a>00367 c0 = *(py);
<a name="l00368"></a>00368
<a name="l00369"></a>00369 <span class="preprocessor">#ifdef ARM_MATH_BIG_ENDIAN</span>
<a name="l00370"></a>00370 <span class="preprocessor"></span>
<a name="l00371"></a>00371 c0 = c0 &lt;&lt; 16u;
<a name="l00372"></a>00372
<a name="l00373"></a>00373 <span class="preprocessor">#endif </span><span class="comment">/* #ifdef ARM_MATH_BIG_ENDIAN */</span>
<a name="l00374"></a>00374
<a name="l00375"></a>00375 <span class="comment">/* Read x[7] */</span>
<a name="l00376"></a>00376 x3 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) px++;
<a name="l00377"></a>00377
<a name="l00378"></a>00378 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00379"></a>00379 acc0 = __SMLALD(x0, c0, acc0);
<a name="l00380"></a>00380 acc1 = __SMLALD(x1, c0, acc1);
<a name="l00381"></a>00381 acc2 = __SMLALDX(x1, c0, acc2);
<a name="l00382"></a>00382 acc3 = __SMLALDX(x3, c0, acc3);
<a name="l00383"></a>00383 }
<a name="l00384"></a>00384
<a name="l00385"></a>00385 <span class="keywordflow">if</span>(k == 2u)
<a name="l00386"></a>00386 {
<a name="l00387"></a>00387 <span class="comment">/* Read y[srcBLen - 5], y[srcBLen - 6] */</span>
<a name="l00388"></a>00388 c0 = *(pb);
<a name="l00389"></a>00389
<a name="l00390"></a>00390 <span class="comment">/* Read x[7], x[8] */</span>
<a name="l00391"></a>00391 x3 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) px++;
<a name="l00392"></a>00392
<a name="l00393"></a>00393 <span class="comment">/* Read x[9] */</span>
<a name="l00394"></a>00394 x2 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) px++;
<a name="l00395"></a>00395
<a name="l00396"></a>00396 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00397"></a>00397 acc0 = __SMLALDX(x0, c0, acc0);
<a name="l00398"></a>00398 acc1 = __SMLALDX(x1, c0, acc1);
<a name="l00399"></a>00399 acc2 = __SMLALDX(x3, c0, acc2);
<a name="l00400"></a>00400 acc3 = __SMLALDX(x2, c0, acc3);
<a name="l00401"></a>00401 }
<a name="l00402"></a>00402
<a name="l00403"></a>00403 <span class="keywordflow">if</span>(k == 3u)
<a name="l00404"></a>00404 {
<a name="l00405"></a>00405 <span class="comment">/* Read y[srcBLen - 5], y[srcBLen - 6] */</span>
<a name="l00406"></a>00406 c0 = *pb--;
<a name="l00407"></a>00407
<a name="l00408"></a>00408 <span class="comment">/* Read x[7], x[8] */</span>
<a name="l00409"></a>00409 x3 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) px++;
<a name="l00410"></a>00410
<a name="l00411"></a>00411 <span class="comment">/* Read x[9] */</span>
<a name="l00412"></a>00412 x2 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) px++;
<a name="l00413"></a>00413
<a name="l00414"></a>00414 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00415"></a>00415 acc0 = __SMLALDX(x0, c0, acc0);
<a name="l00416"></a>00416 acc1 = __SMLALDX(x1, c0, acc1);
<a name="l00417"></a>00417 acc2 = __SMLALDX(x3, c0, acc2);
<a name="l00418"></a>00418 acc3 = __SMLALDX(x2, c0, acc3);
<a name="l00419"></a>00419
<a name="l00420"></a>00420 <span class="preprocessor">#ifdef ARM_MATH_BIG_ENDIAN</span>
<a name="l00421"></a>00421 <span class="preprocessor"></span>
<a name="l00422"></a>00422 <span class="comment">/* Read y[srcBLen - 7] */</span>
<a name="l00423"></a>00423 c0 = (*pb);
<a name="l00424"></a>00424
<a name="l00425"></a>00425 <span class="comment">//c0 = (c0 &amp; 0x0000FFFF)&lt;&lt;16; </span>
<a name="l00426"></a>00426 c0 = (c0) &lt;&lt; 16;
<a name="l00427"></a>00427
<a name="l00428"></a>00428 <span class="preprocessor">#else</span>
<a name="l00429"></a>00429 <span class="preprocessor"></span>
<a name="l00430"></a>00430 <span class="comment">/* Read y[srcBLen - 7] */</span>
<a name="l00431"></a>00431 c0 = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (*pb &gt;&gt; 16);
<a name="l00432"></a>00432
<a name="l00433"></a>00433 <span class="preprocessor">#endif </span><span class="comment">/* #ifdef ARM_MATH_BIG_ENDIAN */</span>
<a name="l00434"></a>00434
<a name="l00435"></a>00435 <span class="comment">/* Read x[10] */</span>
<a name="l00436"></a>00436 x3 = *(<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) px++;
<a name="l00437"></a>00437
<a name="l00438"></a>00438 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00439"></a>00439 acc0 = __SMLALDX(x1, c0, acc0);
<a name="l00440"></a>00440 acc1 = __SMLALD(x2, c0, acc1);
<a name="l00441"></a>00441 acc2 = __SMLALDX(x2, c0, acc2);
<a name="l00442"></a>00442 acc3 = __SMLALDX(x3, c0, acc3);
<a name="l00443"></a>00443 }
<a name="l00444"></a>00444
<a name="l00445"></a>00445
<a name="l00446"></a>00446 <span class="comment">/* Store the results in the accumulators in the destination buffer. */</span>
<a name="l00447"></a>00447
<a name="l00448"></a>00448 <span class="preprocessor">#ifndef ARM_MATH_BIG_ENDIAN</span>
<a name="l00449"></a>00449 <span class="preprocessor"></span>
<a name="l00450"></a>00450 *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(pOut)++ =
<a name="l00451"></a>00451 __PKHBT(__SSAT((acc0 &gt;&gt; 15), 16), __SSAT((acc1 &gt;&gt; 15), 16), 16);
<a name="l00452"></a>00452 *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(pOut)++ =
<a name="l00453"></a>00453 __PKHBT(__SSAT((acc2 &gt;&gt; 15), 16), __SSAT((acc3 &gt;&gt; 15), 16), 16);
<a name="l00454"></a>00454
<a name="l00455"></a>00455 <span class="preprocessor">#else</span>
<a name="l00456"></a>00456 <span class="preprocessor"></span>
<a name="l00457"></a>00457 *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(pOut)++ =
<a name="l00458"></a>00458 __PKHBT(__SSAT((acc1 &gt;&gt; 15), 16), __SSAT((acc0 &gt;&gt; 15), 16), 16);
<a name="l00459"></a>00459 *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(pOut)++ =
<a name="l00460"></a>00460 __PKHBT(__SSAT((acc3 &gt;&gt; 15), 16), __SSAT((acc2 &gt;&gt; 15), 16), 16);
<a name="l00461"></a>00461
<a name="l00462"></a>00462 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_BIG_ENDIAN */</span>
<a name="l00463"></a>00463
<a name="l00464"></a>00464 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00465"></a>00465 px = pIn1 + (count * 4u);
<a name="l00466"></a>00466 py = pSrc2;
<a name="l00467"></a>00467 pb = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *) (py - 1);
<a name="l00468"></a>00468
<a name="l00469"></a>00469 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
<a name="l00470"></a>00470 count++;
<a name="l00471"></a>00471
<a name="l00472"></a>00472 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00473"></a>00473 blkCnt--;
<a name="l00474"></a>00474 }
<a name="l00475"></a>00475
<a name="l00476"></a>00476 <span class="comment">/* If the blockSize2 is not a multiple of 4, compute any remaining output samples here. </span>
<a name="l00477"></a>00477 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00478"></a>00478 blkCnt = blockSize2 % 0x4u;
<a name="l00479"></a>00479
<a name="l00480"></a>00480 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00481"></a>00481 {
<a name="l00482"></a>00482 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00483"></a>00483 sum = 0;
<a name="l00484"></a>00484
<a name="l00485"></a>00485 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00486"></a>00486 k = srcBLen &gt;&gt; 2u;
<a name="l00487"></a>00487
<a name="l00488"></a>00488 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00489"></a>00489 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00490"></a>00490 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00491"></a>00491 {
<a name="l00492"></a>00492 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00493"></a>00493 sum += (<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00494"></a>00494 sum += (<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00495"></a>00495 sum += (<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00496"></a>00496 sum += (<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00497"></a>00497
<a name="l00498"></a>00498 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00499"></a>00499 k--;
<a name="l00500"></a>00500 }
<a name="l00501"></a>00501
<a name="l00502"></a>00502 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00503"></a>00503 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00504"></a>00504 k = srcBLen % 0x4u;
<a name="l00505"></a>00505
<a name="l00506"></a>00506 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00507"></a>00507 {
<a name="l00508"></a>00508 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00509"></a>00509 sum += (<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00510"></a>00510
<a name="l00511"></a>00511 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00512"></a>00512 k--;
<a name="l00513"></a>00513 }
<a name="l00514"></a>00514
<a name="l00515"></a>00515 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00516"></a>00516 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (__SSAT(sum &gt;&gt; 15, 16));
<a name="l00517"></a>00517
<a name="l00518"></a>00518 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00519"></a>00519 px = pIn1 + count;
<a name="l00520"></a>00520 py = pSrc2;
<a name="l00521"></a>00521
<a name="l00522"></a>00522 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
<a name="l00523"></a>00523 count++;
<a name="l00524"></a>00524
<a name="l00525"></a>00525 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00526"></a>00526 blkCnt--;
<a name="l00527"></a>00527 }
<a name="l00528"></a>00528 }
<a name="l00529"></a>00529 <span class="keywordflow">else</span>
<a name="l00530"></a>00530 {
<a name="l00531"></a>00531 <span class="comment">/* If the srcBLen is not a multiple of 4, </span>
<a name="l00532"></a>00532 <span class="comment"> * the blockSize2 loop cannot be unrolled by 4 */</span>
<a name="l00533"></a>00533 blkCnt = blockSize2;
<a name="l00534"></a>00534
<a name="l00535"></a>00535 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00536"></a>00536 {
<a name="l00537"></a>00537 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00538"></a>00538 sum = 0;
<a name="l00539"></a>00539
<a name="l00540"></a>00540 <span class="comment">/* srcBLen number of MACS should be performed */</span>
<a name="l00541"></a>00541 k = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
<a name="l00542"></a>00542
<a name="l00543"></a>00543 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00544"></a>00544 {
<a name="l00545"></a>00545 <span class="comment">/* Perform the multiply-accumulate */</span>
<a name="l00546"></a>00546 sum += (<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) ((<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00547"></a>00547
<a name="l00548"></a>00548 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00549"></a>00549 k--;
<a name="l00550"></a>00550 }
<a name="l00551"></a>00551
<a name="l00552"></a>00552 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00553"></a>00553 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (__SSAT(sum &gt;&gt; 15, 16));
<a name="l00554"></a>00554
<a name="l00555"></a>00555 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00556"></a>00556 px = pIn1 + count;
<a name="l00557"></a>00557 py = pSrc2;
<a name="l00558"></a>00558
<a name="l00559"></a>00559 <span class="comment">/* Increment the MAC count */</span>
<a name="l00560"></a>00560 count++;
<a name="l00561"></a>00561
<a name="l00562"></a>00562 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00563"></a>00563 blkCnt--;
<a name="l00564"></a>00564 }
<a name="l00565"></a>00565 }
<a name="l00566"></a>00566
<a name="l00567"></a>00567
<a name="l00568"></a>00568 <span class="comment">/* -------------------------- </span>
<a name="l00569"></a>00569 <span class="comment"> * Initializations of stage3 </span>
<a name="l00570"></a>00570 <span class="comment"> * -------------------------*/</span>
<a name="l00571"></a>00571
<a name="l00572"></a>00572 <span class="comment">/* sum += x[srcALen-srcBLen+1] * y[srcBLen-1] + x[srcALen-srcBLen+2] * y[srcBLen-2] +...+ x[srcALen-1] * y[1] </span>
<a name="l00573"></a>00573 <span class="comment"> * sum += x[srcALen-srcBLen+2] * y[srcBLen-1] + x[srcALen-srcBLen+3] * y[srcBLen-2] +...+ x[srcALen-1] * y[2] </span>
<a name="l00574"></a>00574 <span class="comment"> * .... </span>
<a name="l00575"></a>00575 <span class="comment"> * sum += x[srcALen-2] * y[srcBLen-1] + x[srcALen-1] * y[srcBLen-2] </span>
<a name="l00576"></a>00576 <span class="comment"> * sum += x[srcALen-1] * y[srcBLen-1] </span>
<a name="l00577"></a>00577 <span class="comment"> */</span>
<a name="l00578"></a>00578
<a name="l00579"></a>00579 <span class="comment">/* In this stage the MAC operations are decreased by 1 for every iteration. </span>
<a name="l00580"></a>00580 <span class="comment"> The blockSize3 variable holds the number of MAC operations performed */</span>
<a name="l00581"></a>00581
<a name="l00582"></a>00582 blockSize3 = srcBLen - 1u;
<a name="l00583"></a>00583
<a name="l00584"></a>00584 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00585"></a>00585 pSrc1 = (pIn1 + <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>) - (srcBLen - 1u);
<a name="l00586"></a>00586 px = pSrc1;
<a name="l00587"></a>00587
<a name="l00588"></a>00588 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00589"></a>00589 pSrc2 = pIn2 + (srcBLen - 1u);
<a name="l00590"></a>00590 pIn2 = pSrc2 - 1u;
<a name="l00591"></a>00591 py = pIn2;
<a name="l00592"></a>00592
<a name="l00593"></a>00593 <span class="comment">/* ------------------- </span>
<a name="l00594"></a>00594 <span class="comment"> * Stage3 process </span>
<a name="l00595"></a>00595 <span class="comment"> * ------------------*/</span>
<a name="l00596"></a>00596
<a name="l00597"></a>00597 <span class="comment">/* For loop unrolling by 4, this stage is divided into two. */</span>
<a name="l00598"></a>00598 <span class="comment">/* First part of this stage computes the MAC operations greater than 4 */</span>
<a name="l00599"></a>00599 <span class="comment">/* Second part of this stage computes the MAC operations less than or equal to 4 */</span>
<a name="l00600"></a>00600
<a name="l00601"></a>00601 <span class="comment">/* The first part of the stage starts here */</span>
<a name="l00602"></a>00602 j = blockSize3 &gt;&gt; 2u;
<a name="l00603"></a>00603
<a name="l00604"></a>00604 <span class="keywordflow">while</span>((j &gt; 0u) &amp;&amp; (blockSize3 &gt; 0u))
<a name="l00605"></a>00605 {
<a name="l00606"></a>00606 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00607"></a>00607 sum = 0;
<a name="l00608"></a>00608
<a name="l00609"></a>00609 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00610"></a>00610 k = blockSize3 &gt;&gt; 2u;
<a name="l00611"></a>00611
<a name="l00612"></a>00612 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00613"></a>00613 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00614"></a>00614 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00615"></a>00615 {
<a name="l00616"></a>00616 <span class="comment">/* x[srcALen - srcBLen + 1], x[srcALen - srcBLen + 2] are multiplied </span>
<a name="l00617"></a>00617 <span class="comment"> * with y[srcBLen - 1], y[srcBLen - 2] respectively */</span>
<a name="l00618"></a>00618 sum = __SMLALDX(*<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(px)++, *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(py)--, sum);
<a name="l00619"></a>00619 <span class="comment">/* x[srcALen - srcBLen + 3], x[srcALen - srcBLen + 4] are multiplied </span>
<a name="l00620"></a>00620 <span class="comment"> * with y[srcBLen - 3], y[srcBLen - 4] respectively */</span>
<a name="l00621"></a>00621 sum = __SMLALDX(*<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(px)++, *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(py)--, sum);
<a name="l00622"></a>00622
<a name="l00623"></a>00623 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00624"></a>00624 k--;
<a name="l00625"></a>00625 }
<a name="l00626"></a>00626
<a name="l00627"></a>00627 <span class="comment">/* For the next MAC operations, the pointer py is used without SIMD </span>
<a name="l00628"></a>00628 <span class="comment"> * So, py is incremented by 1 */</span>
<a name="l00629"></a>00629 py = py + 1u;
<a name="l00630"></a>00630
<a name="l00631"></a>00631 <span class="comment">/* If the blockSize3 is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00632"></a>00632 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00633"></a>00633 k = blockSize3 % 0x4u;
<a name="l00634"></a>00634
<a name="l00635"></a>00635 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00636"></a>00636 {
<a name="l00637"></a>00637 <span class="comment">/* sum += x[srcALen - srcBLen + 5] * y[srcBLen - 5] */</span>
<a name="l00638"></a>00638 sum = __SMLALD(*px++, *py--, sum);
<a name="l00639"></a>00639
<a name="l00640"></a>00640 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00641"></a>00641 k--;
<a name="l00642"></a>00642 }
<a name="l00643"></a>00643
<a name="l00644"></a>00644 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00645"></a>00645 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (__SSAT((sum &gt;&gt; 15), 16));
<a name="l00646"></a>00646
<a name="l00647"></a>00647 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00648"></a>00648 px = ++pSrc1;
<a name="l00649"></a>00649 py = pIn2;
<a name="l00650"></a>00650
<a name="l00651"></a>00651 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00652"></a>00652 blockSize3--;
<a name="l00653"></a>00653
<a name="l00654"></a>00654 j--;
<a name="l00655"></a>00655 }
<a name="l00656"></a>00656
<a name="l00657"></a>00657 <span class="comment">/* The second part of the stage starts here */</span>
<a name="l00658"></a>00658 <span class="comment">/* SIMD is not used for the next MAC operations, </span>
<a name="l00659"></a>00659 <span class="comment"> * so pointer py is updated to read only one sample at a time */</span>
<a name="l00660"></a>00660 py = py + 1u;
<a name="l00661"></a>00661
<a name="l00662"></a>00662 <span class="keywordflow">while</span>(blockSize3 &gt; 0u)
<a name="l00663"></a>00663 {
<a name="l00664"></a>00664 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00665"></a>00665 sum = 0;
<a name="l00666"></a>00666
<a name="l00667"></a>00667 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00668"></a>00668 k = blockSize3;
<a name="l00669"></a>00669
<a name="l00670"></a>00670 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00671"></a>00671 {
<a name="l00672"></a>00672 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00673"></a>00673 <span class="comment">/* sum += x[srcALen-1] * y[srcBLen-1] */</span>
<a name="l00674"></a>00674 sum = __SMLALD(*px++, *py--, sum);
<a name="l00675"></a>00675
<a name="l00676"></a>00676 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00677"></a>00677 k--;
<a name="l00678"></a>00678 }
<a name="l00679"></a>00679
<a name="l00680"></a>00680 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00681"></a>00681 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (__SSAT((sum &gt;&gt; 15), 16));
<a name="l00682"></a>00682
<a name="l00683"></a>00683 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00684"></a>00684 px = ++pSrc1;
<a name="l00685"></a>00685 py = pSrc2;
<a name="l00686"></a>00686
<a name="l00687"></a>00687 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00688"></a>00688 blockSize3--;
<a name="l00689"></a>00689 }
<a name="l00690"></a>00690
<a name="l00691"></a>00691 <span class="preprocessor">#else</span>
<a name="l00692"></a>00692 <span class="preprocessor"></span>
<a name="l00693"></a>00693 <span class="comment">/* Run the below code for Cortex-M0 */</span>
<a name="l00694"></a>00694
<a name="l00695"></a>00695 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *pIn1 = pSrcA; <span class="comment">/* input pointer */</span>
<a name="l00696"></a>00696 <a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a> *pIn2 = pSrcB; <span class="comment">/* coefficient pointer */</span>
<a name="l00697"></a>00697 <a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a> sum; <span class="comment">/* Accumulator */</span>
<a name="l00698"></a>00698 uint32_t i, j; <span class="comment">/* loop counter */</span>
<a name="l00699"></a>00699
<a name="l00700"></a>00700 <span class="comment">/* Loop to calculate output of convolution for output length number of times */</span>
<a name="l00701"></a>00701 <span class="keywordflow">for</span> (i = 0; i &lt; (srcALen + srcBLen - 1); i++)
<a name="l00702"></a>00702 {
<a name="l00703"></a>00703 <span class="comment">/* Initialize sum with zero to carry on MAC operations */</span>
<a name="l00704"></a>00704 sum = 0;
<a name="l00705"></a>00705
<a name="l00706"></a>00706 <span class="comment">/* Loop to perform MAC operations according to convolution equation */</span>
<a name="l00707"></a>00707 <span class="keywordflow">for</span> (j = 0; j &lt;= i; j++)
<a name="l00708"></a>00708 {
<a name="l00709"></a>00709 <span class="comment">/* Check the array limitations */</span>
<a name="l00710"></a>00710 <span class="keywordflow">if</span>(((i - j) &lt; <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>) &amp;&amp; (j &lt; srcALen))
<a name="l00711"></a>00711 {
<a name="l00712"></a>00712 <span class="comment">/* z[i] += x[i-j] * y[j] */</span>
<a name="l00713"></a>00713 sum += (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) pIn1[j] * (pIn2[i - j]);
<a name="l00714"></a>00714 }
<a name="l00715"></a>00715 }
<a name="l00716"></a>00716
<a name="l00717"></a>00717 <span class="comment">/* Store the output in the destination buffer */</span>
<a name="l00718"></a>00718 pDst[i] = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) __SSAT((sum &gt;&gt; 15u), 16u);
<a name="l00719"></a>00719 }
<a name="l00720"></a>00720
<a name="l00721"></a>00721 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_CM0 */</span>
<a name="l00722"></a>00722
<a name="l00723"></a>00723 }
<a name="l00724"></a>00724
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