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<h1>arm_correlate_fast_q31.c</h1> </div>
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<a href="arm__correlate__fast__q31_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_correlate_fast_q31.c </span>
<a name="l00009"></a>00009 <span class="comment">* </span>
<a name="l00010"></a>00010 <span class="comment">* Description: Fast Q31 Correlation. </span>
<a name="l00011"></a>00011 <span class="comment">* </span>
<a name="l00012"></a>00012 <span class="comment">* Target Processor: Cortex-M4/Cortex-M3</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
<a name="l00030"></a>00030 <span class="preprocessor">#include &quot;<a class="code" href="arm__math_8h.html">arm_math.h</a>&quot;</span>
<a name="l00031"></a>00031
<a name="l00070"></a><a class="code" href="group___corr.html#gabecd3d7b077dbbef43f93e9e037815ed">00070</a> <span class="keywordtype">void</span> <a class="code" href="group___corr.html#gabecd3d7b077dbbef43f93e9e037815ed" title="Correlation of Q31 sequences (fast version) for Cortex-M3 and Cortex-M4.">arm_correlate_fast_q31</a>(
<a name="l00071"></a>00071 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pSrcA,
<a name="l00072"></a>00072 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>,
<a name="l00073"></a>00073 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pSrcB,
<a name="l00074"></a>00074 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>,
<a name="l00075"></a>00075 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pDst)
<a name="l00076"></a>00076 {
<a name="l00077"></a>00077 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pIn1; <span class="comment">/* inputA pointer */</span>
<a name="l00078"></a>00078 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pIn2; <span class="comment">/* inputB pointer */</span>
<a name="l00079"></a>00079 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pOut = pDst; <span class="comment">/* output pointer */</span>
<a name="l00080"></a>00080 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *px; <span class="comment">/* Intermediate inputA pointer */</span>
<a name="l00081"></a>00081 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *py; <span class="comment">/* Intermediate inputB pointer */</span>
<a name="l00082"></a>00082 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pSrc1; <span class="comment">/* Intermediate pointers */</span>
<a name="l00083"></a>00083 <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>
<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> x0, x1, x2, x3, c0; <span class="comment">/* temporary variables for holding input and coefficient values */</span>
<a name="l00085"></a>00085 uint32_t j, k = 0u, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3; <span class="comment">/* loop counter */</span>
<a name="l00086"></a>00086 int32_t inc = 1; <span class="comment">/* Destination address modifier */</span>
<a name="l00087"></a>00087
<a name="l00088"></a>00088
<a name="l00089"></a>00089 <span class="comment">/* The algorithm implementation is based on the lengths of the inputs. */</span>
<a name="l00090"></a>00090 <span class="comment">/* srcB is always made to slide across srcA. */</span>
<a name="l00091"></a>00091 <span class="comment">/* So srcBLen is always considered as shorter or equal to srcALen */</span>
<a name="l00092"></a>00092 <span class="keywordflow">if</span>(srcALen &gt;= srcBLen)
<a name="l00093"></a>00093 {
<a name="l00094"></a>00094 <span class="comment">/* Initialization of inputA pointer */</span>
<a name="l00095"></a>00095 pIn1 = (pSrcA);
<a name="l00096"></a>00096
<a name="l00097"></a>00097 <span class="comment">/* Initialization of inputB pointer */</span>
<a name="l00098"></a>00098 pIn2 = (pSrcB);
<a name="l00099"></a>00099
<a name="l00100"></a>00100 <span class="comment">/* Number of output samples is calculated */</span>
<a name="l00101"></a>00101 outBlockSize = (2u * <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>) - 1u;
<a name="l00102"></a>00102
<a name="l00103"></a>00103 <span class="comment">/* When srcALen &gt; srcBLen, zero padding is done to srcB </span>
<a name="l00104"></a>00104 <span class="comment"> * to make their lengths equal. </span>
<a name="l00105"></a>00105 <span class="comment"> * Instead, (outBlockSize - (srcALen + srcBLen - 1)) </span>
<a name="l00106"></a>00106 <span class="comment"> * number of output samples are made zero */</span>
<a name="l00107"></a>00107 j = outBlockSize - (srcALen + (srcBLen - 1u));
<a name="l00108"></a>00108
<a name="l00109"></a>00109 <span class="comment">/* Updating the pointer position to non zero value */</span>
<a name="l00110"></a>00110 pOut += j;
<a name="l00111"></a>00111
<a name="l00112"></a>00112 }
<a name="l00113"></a>00113 <span class="keywordflow">else</span>
<a name="l00114"></a>00114 {
<a name="l00115"></a>00115 <span class="comment">/* Initialization of inputA pointer */</span>
<a name="l00116"></a>00116 pIn1 = (pSrcB);
<a name="l00117"></a>00117
<a name="l00118"></a>00118 <span class="comment">/* Initialization of inputB pointer */</span>
<a name="l00119"></a>00119 pIn2 = (pSrcA);
<a name="l00120"></a>00120
<a name="l00121"></a>00121 <span class="comment">/* srcBLen is always considered as shorter or equal to srcALen */</span>
<a name="l00122"></a>00122 j = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
<a name="l00123"></a>00123 srcBLen = <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>;
<a name="l00124"></a>00124 srcALen = j;
<a name="l00125"></a>00125
<a name="l00126"></a>00126 <span class="comment">/* CORR(x, y) = Reverse order(CORR(y, x)) */</span>
<a name="l00127"></a>00127 <span class="comment">/* Hence set the destination pointer to point to the last output sample */</span>
<a name="l00128"></a>00128 pOut = pDst + ((srcALen + <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>) - 2u);
<a name="l00129"></a>00129
<a name="l00130"></a>00130 <span class="comment">/* Destination address modifier is set to -1 */</span>
<a name="l00131"></a>00131 inc = -1;
<a name="l00132"></a>00132
<a name="l00133"></a>00133 }
<a name="l00134"></a>00134
<a name="l00135"></a>00135 <span class="comment">/* The function is internally </span>
<a name="l00136"></a>00136 <span class="comment"> * divided into three parts according to the number of multiplications that has to be </span>
<a name="l00137"></a>00137 <span class="comment"> * taken place between inputA samples and inputB samples. In the first part of the </span>
<a name="l00138"></a>00138 <span class="comment"> * algorithm, the multiplications increase by one for every iteration. </span>
<a name="l00139"></a>00139 <span class="comment"> * In the second part of the algorithm, srcBLen number of multiplications are done. </span>
<a name="l00140"></a>00140 <span class="comment"> * In the third part of the algorithm, the multiplications decrease by one </span>
<a name="l00141"></a>00141 <span class="comment"> * for every iteration.*/</span>
<a name="l00142"></a>00142 <span class="comment">/* The algorithm is implemented in three stages. </span>
<a name="l00143"></a>00143 <span class="comment"> * The loop counters of each stage is initiated here. */</span>
<a name="l00144"></a>00144 blockSize1 = srcBLen - 1u;
<a name="l00145"></a>00145 blockSize2 = srcALen - (srcBLen - 1u);
<a name="l00146"></a>00146 blockSize3 = blockSize1;
<a name="l00147"></a>00147
<a name="l00148"></a>00148 <span class="comment">/* -------------------------- </span>
<a name="l00149"></a>00149 <span class="comment"> * Initializations of stage1 </span>
<a name="l00150"></a>00150 <span class="comment"> * -------------------------*/</span>
<a name="l00151"></a>00151
<a name="l00152"></a>00152 <span class="comment">/* sum = x[0] * y[srcBlen - 1] </span>
<a name="l00153"></a>00153 <span class="comment"> * sum = x[0] * y[srcBlen - 2] + x[1] * y[srcBlen - 1] </span>
<a name="l00154"></a>00154 <span class="comment"> * .... </span>
<a name="l00155"></a>00155 <span class="comment"> * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1] </span>
<a name="l00156"></a>00156 <span class="comment"> */</span>
<a name="l00157"></a>00157
<a name="l00158"></a>00158 <span class="comment">/* In this stage the MAC operations are increased by 1 for every iteration. </span>
<a name="l00159"></a>00159 <span class="comment"> The count variable holds the number of MAC operations performed */</span>
<a name="l00160"></a>00160 count = 1u;
<a name="l00161"></a>00161
<a name="l00162"></a>00162 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00163"></a>00163 px = pIn1;
<a name="l00164"></a>00164
<a name="l00165"></a>00165 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00166"></a>00166 pSrc1 = pIn2 + (srcBLen - 1u);
<a name="l00167"></a>00167 py = pSrc1;
<a name="l00168"></a>00168
<a name="l00169"></a>00169 <span class="comment">/* ------------------------ </span>
<a name="l00170"></a>00170 <span class="comment"> * Stage1 process </span>
<a name="l00171"></a>00171 <span class="comment"> * ----------------------*/</span>
<a name="l00172"></a>00172
<a name="l00173"></a>00173 <span class="comment">/* The first stage starts here */</span>
<a name="l00174"></a>00174 <span class="keywordflow">while</span>(blockSize1 &gt; 0u)
<a name="l00175"></a>00175 {
<a name="l00176"></a>00176 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00177"></a>00177 sum = 0;
<a name="l00178"></a>00178
<a name="l00179"></a>00179 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00180"></a>00180 k = count &gt;&gt; 2;
<a name="l00181"></a>00181
<a name="l00182"></a>00182 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00183"></a>00183 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00184"></a>00184 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00185"></a>00185 {
<a name="l00186"></a>00186 <span class="comment">/* x[0] * y[srcBLen - 4] */</span>
<a name="l00187"></a>00187 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00188"></a>00188 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00189"></a>00189 <span class="comment">/* x[1] * y[srcBLen - 3] */</span>
<a name="l00190"></a>00190 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00191"></a>00191 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00192"></a>00192 <span class="comment">/* x[2] * y[srcBLen - 2] */</span>
<a name="l00193"></a>00193 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00194"></a>00194 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00195"></a>00195 <span class="comment">/* x[3] * y[srcBLen - 1] */</span>
<a name="l00196"></a>00196 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00197"></a>00197 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00198"></a>00198
<a name="l00199"></a>00199 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00200"></a>00200 k--;
<a name="l00201"></a>00201 }
<a name="l00202"></a>00202
<a name="l00203"></a>00203 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00204"></a>00204 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00205"></a>00205 k = count % 0x4u;
<a name="l00206"></a>00206
<a name="l00207"></a>00207 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00208"></a>00208 {
<a name="l00209"></a>00209 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00210"></a>00210 <span class="comment">/* x[0] * y[srcBLen - 1] */</span>
<a name="l00211"></a>00211 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00212"></a>00212 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00213"></a>00213
<a name="l00214"></a>00214 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00215"></a>00215 k--;
<a name="l00216"></a>00216 }
<a name="l00217"></a>00217
<a name="l00218"></a>00218 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00219"></a>00219 *pOut = sum &lt;&lt; 1;
<a name="l00220"></a>00220 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
<a name="l00221"></a>00221 pOut += inc;
<a name="l00222"></a>00222
<a name="l00223"></a>00223 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00224"></a>00224 py = pSrc1 - count;
<a name="l00225"></a>00225 px = pIn1;
<a name="l00226"></a>00226
<a name="l00227"></a>00227 <span class="comment">/* Increment the MAC count */</span>
<a name="l00228"></a>00228 count++;
<a name="l00229"></a>00229
<a name="l00230"></a>00230 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00231"></a>00231 blockSize1--;
<a name="l00232"></a>00232 }
<a name="l00233"></a>00233
<a name="l00234"></a>00234 <span class="comment">/* -------------------------- </span>
<a name="l00235"></a>00235 <span class="comment"> * Initializations of stage2 </span>
<a name="l00236"></a>00236 <span class="comment"> * ------------------------*/</span>
<a name="l00237"></a>00237
<a name="l00238"></a>00238 <span class="comment">/* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1] </span>
<a name="l00239"></a>00239 <span class="comment"> * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1] </span>
<a name="l00240"></a>00240 <span class="comment"> * .... </span>
<a name="l00241"></a>00241 <span class="comment"> * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1] </span>
<a name="l00242"></a>00242 <span class="comment"> */</span>
<a name="l00243"></a>00243
<a name="l00244"></a>00244 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00245"></a>00245 px = pIn1;
<a name="l00246"></a>00246
<a name="l00247"></a>00247 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00248"></a>00248 py = pIn2;
<a name="l00249"></a>00249
<a name="l00250"></a>00250 <span class="comment">/* count is index by which the pointer pIn1 to be incremented */</span>
<a name="l00251"></a>00251 count = 1u;
<a name="l00252"></a>00252
<a name="l00253"></a>00253 <span class="comment">/* ------------------- </span>
<a name="l00254"></a>00254 <span class="comment"> * Stage2 process </span>
<a name="l00255"></a>00255 <span class="comment"> * ------------------*/</span>
<a name="l00256"></a>00256
<a name="l00257"></a>00257 <span class="comment">/* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed. </span>
<a name="l00258"></a>00258 <span class="comment"> * So, to loop unroll over blockSize2, </span>
<a name="l00259"></a>00259 <span class="comment"> * srcBLen should be greater than or equal to 4 */</span>
<a name="l00260"></a>00260 <span class="keywordflow">if</span>(srcBLen &gt;= 4u)
<a name="l00261"></a>00261 {
<a name="l00262"></a>00262 <span class="comment">/* Loop unroll over blockSize2, by 4 */</span>
<a name="l00263"></a>00263 blkCnt = blockSize2 &gt;&gt; 2u;
<a name="l00264"></a>00264
<a name="l00265"></a>00265 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00266"></a>00266 {
<a name="l00267"></a>00267 <span class="comment">/* Set all accumulators to zero */</span>
<a name="l00268"></a>00268 acc0 = 0;
<a name="l00269"></a>00269 acc1 = 0;
<a name="l00270"></a>00270 acc2 = 0;
<a name="l00271"></a>00271 acc3 = 0;
<a name="l00272"></a>00272
<a name="l00273"></a>00273 <span class="comment">/* read x[0], x[1], x[2] samples */</span>
<a name="l00274"></a>00274 x0 = *(px++);
<a name="l00275"></a>00275 x1 = *(px++);
<a name="l00276"></a>00276 x2 = *(px++);
<a name="l00277"></a>00277
<a name="l00278"></a>00278 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00279"></a>00279 k = srcBLen &gt;&gt; 2u;
<a name="l00280"></a>00280
<a name="l00281"></a>00281 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00282"></a>00282 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00283"></a>00283 <span class="keywordflow">do</span>
<a name="l00284"></a>00284 {
<a name="l00285"></a>00285 <span class="comment">/* Read y[0] sample */</span>
<a name="l00286"></a>00286 c0 = *(py++);
<a name="l00287"></a>00287
<a name="l00288"></a>00288 <span class="comment">/* Read x[3] sample */</span>
<a name="l00289"></a>00289 x3 = *(px++);
<a name="l00290"></a>00290
<a name="l00291"></a>00291 <span class="comment">/* Perform the multiply-accumulate */</span>
<a name="l00292"></a>00292 <span class="comment">/* acc0 += x[0] * y[0] */</span>
<a name="l00293"></a>00293 acc0 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc0 &lt;&lt; 32) + ((q63_t) x0 * c0)) &gt;&gt; 32);
<a name="l00294"></a>00294 <span class="comment">/* acc1 += x[1] * y[0] */</span>
<a name="l00295"></a>00295 acc1 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc1 &lt;&lt; 32) + ((q63_t) x1 * c0)) &gt;&gt; 32);
<a name="l00296"></a>00296 <span class="comment">/* acc2 += x[2] * y[0] */</span>
<a name="l00297"></a>00297 acc2 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc2 &lt;&lt; 32) + ((q63_t) x2 * c0)) &gt;&gt; 32);
<a name="l00298"></a>00298 <span class="comment">/* acc3 += x[3] * y[0] */</span>
<a name="l00299"></a>00299 acc3 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc3 &lt;&lt; 32) + ((q63_t) x3 * c0)) &gt;&gt; 32);
<a name="l00300"></a>00300
<a name="l00301"></a>00301 <span class="comment">/* Read y[1] sample */</span>
<a name="l00302"></a>00302 c0 = *(py++);
<a name="l00303"></a>00303
<a name="l00304"></a>00304 <span class="comment">/* Read x[4] sample */</span>
<a name="l00305"></a>00305 x0 = *(px++);
<a name="l00306"></a>00306
<a name="l00307"></a>00307 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00308"></a>00308 <span class="comment">/* acc0 += x[1] * y[1] */</span>
<a name="l00309"></a>00309 acc0 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc0 &lt;&lt; 32) + ((q63_t) x1 * c0)) &gt;&gt; 32);
<a name="l00310"></a>00310 <span class="comment">/* acc1 += x[2] * y[1] */</span>
<a name="l00311"></a>00311 acc1 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc1 &lt;&lt; 32) + ((q63_t) x2 * c0)) &gt;&gt; 32);
<a name="l00312"></a>00312 <span class="comment">/* acc2 += x[3] * y[1] */</span>
<a name="l00313"></a>00313 acc2 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc2 &lt;&lt; 32) + ((q63_t) x3 * c0)) &gt;&gt; 32);
<a name="l00314"></a>00314 <span class="comment">/* acc3 += x[4] * y[1] */</span>
<a name="l00315"></a>00315 acc3 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc3 &lt;&lt; 32) + ((q63_t) x0 * c0)) &gt;&gt; 32);
<a name="l00316"></a>00316
<a name="l00317"></a>00317 <span class="comment">/* Read y[2] sample */</span>
<a name="l00318"></a>00318 c0 = *(py++);
<a name="l00319"></a>00319
<a name="l00320"></a>00320 <span class="comment">/* Read x[5] sample */</span>
<a name="l00321"></a>00321 x1 = *(px++);
<a name="l00322"></a>00322
<a name="l00323"></a>00323 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00324"></a>00324 <span class="comment">/* acc0 += x[2] * y[2] */</span>
<a name="l00325"></a>00325 acc0 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc0 &lt;&lt; 32) + ((q63_t) x2 * c0)) &gt;&gt; 32);
<a name="l00326"></a>00326 <span class="comment">/* acc1 += x[3] * y[2] */</span>
<a name="l00327"></a>00327 acc1 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc1 &lt;&lt; 32) + ((q63_t) x3 * c0)) &gt;&gt; 32);
<a name="l00328"></a>00328 <span class="comment">/* acc2 += x[4] * y[2] */</span>
<a name="l00329"></a>00329 acc2 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc2 &lt;&lt; 32) + ((q63_t) x0 * c0)) &gt;&gt; 32);
<a name="l00330"></a>00330 <span class="comment">/* acc3 += x[5] * y[2] */</span>
<a name="l00331"></a>00331 acc3 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc3 &lt;&lt; 32) + ((q63_t) x1 * c0)) &gt;&gt; 32);
<a name="l00332"></a>00332
<a name="l00333"></a>00333 <span class="comment">/* Read y[3] sample */</span>
<a name="l00334"></a>00334 c0 = *(py++);
<a name="l00335"></a>00335
<a name="l00336"></a>00336 <span class="comment">/* Read x[6] sample */</span>
<a name="l00337"></a>00337 x2 = *(px++);
<a name="l00338"></a>00338
<a name="l00339"></a>00339 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00340"></a>00340 <span class="comment">/* acc0 += x[3] * y[3] */</span>
<a name="l00341"></a>00341 acc0 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc0 &lt;&lt; 32) + ((q63_t) x3 * c0)) &gt;&gt; 32);
<a name="l00342"></a>00342 <span class="comment">/* acc1 += x[4] * y[3] */</span>
<a name="l00343"></a>00343 acc1 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc1 &lt;&lt; 32) + ((q63_t) x0 * c0)) &gt;&gt; 32);
<a name="l00344"></a>00344 <span class="comment">/* acc2 += x[5] * y[3] */</span>
<a name="l00345"></a>00345 acc2 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc2 &lt;&lt; 32) + ((q63_t) x1 * c0)) &gt;&gt; 32);
<a name="l00346"></a>00346 <span class="comment">/* acc3 += x[6] * y[3] */</span>
<a name="l00347"></a>00347 acc3 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc3 &lt;&lt; 32) + ((q63_t) x2 * c0)) &gt;&gt; 32);
<a name="l00348"></a>00348
<a name="l00349"></a>00349
<a name="l00350"></a>00350 } <span class="keywordflow">while</span>(--k);
<a name="l00351"></a>00351
<a name="l00352"></a>00352 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00353"></a>00353 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00354"></a>00354 k = srcBLen % 0x4u;
<a name="l00355"></a>00355
<a name="l00356"></a>00356 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00357"></a>00357 {
<a name="l00358"></a>00358 <span class="comment">/* Read y[4] sample */</span>
<a name="l00359"></a>00359 c0 = *(py++);
<a name="l00360"></a>00360
<a name="l00361"></a>00361 <span class="comment">/* Read x[7] sample */</span>
<a name="l00362"></a>00362 x3 = *(px++);
<a name="l00363"></a>00363
<a name="l00364"></a>00364 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00365"></a>00365 <span class="comment">/* acc0 += x[4] * y[4] */</span>
<a name="l00366"></a>00366 acc0 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc0 &lt;&lt; 32) + ((q63_t) x0 * c0)) &gt;&gt; 32);
<a name="l00367"></a>00367 <span class="comment">/* acc1 += x[5] * y[4] */</span>
<a name="l00368"></a>00368 acc1 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc1 &lt;&lt; 32) + ((q63_t) x1 * c0)) &gt;&gt; 32);
<a name="l00369"></a>00369 <span class="comment">/* acc2 += x[6] * y[4] */</span>
<a name="l00370"></a>00370 acc2 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc2 &lt;&lt; 32) + ((q63_t) x2 * c0)) &gt;&gt; 32);
<a name="l00371"></a>00371 <span class="comment">/* acc3 += x[7] * y[4] */</span>
<a name="l00372"></a>00372 acc3 = (<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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) acc3 &lt;&lt; 32) + ((q63_t) x3 * c0)) &gt;&gt; 32);
<a name="l00373"></a>00373
<a name="l00374"></a>00374 <span class="comment">/* Reuse the present samples for the next MAC */</span>
<a name="l00375"></a>00375 x0 = x1;
<a name="l00376"></a>00376 x1 = x2;
<a name="l00377"></a>00377 x2 = x3;
<a name="l00378"></a>00378
<a name="l00379"></a>00379 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00380"></a>00380 k--;
<a name="l00381"></a>00381 }
<a name="l00382"></a>00382
<a name="l00383"></a>00383 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00384"></a>00384 *pOut = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (acc0 &lt;&lt; 1);
<a name="l00385"></a>00385 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
<a name="l00386"></a>00386 pOut += inc;
<a name="l00387"></a>00387
<a name="l00388"></a>00388 *pOut = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (acc1 &lt;&lt; 1);
<a name="l00389"></a>00389 pOut += inc;
<a name="l00390"></a>00390
<a name="l00391"></a>00391 *pOut = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (acc2 &lt;&lt; 1);
<a name="l00392"></a>00392 pOut += inc;
<a name="l00393"></a>00393
<a name="l00394"></a>00394 *pOut = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (acc3 &lt;&lt; 1);
<a name="l00395"></a>00395 pOut += inc;
<a name="l00396"></a>00396
<a name="l00397"></a>00397 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00398"></a>00398 px = pIn1 + (count * 4u);
<a name="l00399"></a>00399 py = pIn2;
<a name="l00400"></a>00400
<a name="l00401"></a>00401 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
<a name="l00402"></a>00402 count++;
<a name="l00403"></a>00403
<a name="l00404"></a>00404 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00405"></a>00405 blkCnt--;
<a name="l00406"></a>00406 }
<a name="l00407"></a>00407
<a name="l00408"></a>00408 <span class="comment">/* If the blockSize2 is not a multiple of 4, compute any remaining output samples here. </span>
<a name="l00409"></a>00409 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00410"></a>00410 blkCnt = blockSize2 % 0x4u;
<a name="l00411"></a>00411
<a name="l00412"></a>00412 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00413"></a>00413 {
<a name="l00414"></a>00414 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00415"></a>00415 sum = 0;
<a name="l00416"></a>00416
<a name="l00417"></a>00417 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00418"></a>00418 k = srcBLen &gt;&gt; 2u;
<a name="l00419"></a>00419
<a name="l00420"></a>00420 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00421"></a>00421 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00422"></a>00422 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00423"></a>00423 {
<a name="l00424"></a>00424 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00425"></a>00425 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00426"></a>00426 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00427"></a>00427 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00428"></a>00428 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00429"></a>00429 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00430"></a>00430 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00431"></a>00431 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00432"></a>00432 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00433"></a>00433
<a name="l00434"></a>00434 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00435"></a>00435 k--;
<a name="l00436"></a>00436 }
<a name="l00437"></a>00437
<a name="l00438"></a>00438 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00439"></a>00439 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00440"></a>00440 k = srcBLen % 0x4u;
<a name="l00441"></a>00441
<a name="l00442"></a>00442 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00443"></a>00443 {
<a name="l00444"></a>00444 <span class="comment">/* Perform the multiply-accumulate */</span>
<a name="l00445"></a>00445 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00446"></a>00446 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00447"></a>00447
<a name="l00448"></a>00448 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00449"></a>00449 k--;
<a name="l00450"></a>00450 }
<a name="l00451"></a>00451
<a name="l00452"></a>00452 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00453"></a>00453 *pOut = sum &lt;&lt; 1;
<a name="l00454"></a>00454 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
<a name="l00455"></a>00455 pOut += inc;
<a name="l00456"></a>00456
<a name="l00457"></a>00457 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00458"></a>00458 px = pIn1 + count;
<a name="l00459"></a>00459 py = pIn2;
<a name="l00460"></a>00460
<a name="l00461"></a>00461 <span class="comment">/* Increment the MAC count */</span>
<a name="l00462"></a>00462 count++;
<a name="l00463"></a>00463
<a name="l00464"></a>00464 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00465"></a>00465 blkCnt--;
<a name="l00466"></a>00466 }
<a name="l00467"></a>00467 }
<a name="l00468"></a>00468 <span class="keywordflow">else</span>
<a name="l00469"></a>00469 {
<a name="l00470"></a>00470 <span class="comment">/* If the srcBLen is not a multiple of 4, </span>
<a name="l00471"></a>00471 <span class="comment"> * the blockSize2 loop cannot be unrolled by 4 */</span>
<a name="l00472"></a>00472 blkCnt = blockSize2;
<a name="l00473"></a>00473
<a name="l00474"></a>00474 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00475"></a>00475 {
<a name="l00476"></a>00476 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00477"></a>00477 sum = 0;
<a name="l00478"></a>00478
<a name="l00479"></a>00479 <span class="comment">/* Loop over srcBLen */</span>
<a name="l00480"></a>00480 k = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
<a name="l00481"></a>00481
<a name="l00482"></a>00482 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00483"></a>00483 {
<a name="l00484"></a>00484 <span class="comment">/* Perform the multiply-accumulate */</span>
<a name="l00485"></a>00485 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00486"></a>00486 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00487"></a>00487
<a name="l00488"></a>00488 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00489"></a>00489 k--;
<a name="l00490"></a>00490 }
<a name="l00491"></a>00491
<a name="l00492"></a>00492 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00493"></a>00493 *pOut = sum &lt;&lt; 1;
<a name="l00494"></a>00494 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
<a name="l00495"></a>00495 pOut += inc;
<a name="l00496"></a>00496
<a name="l00497"></a>00497 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00498"></a>00498 px = pIn1 + count;
<a name="l00499"></a>00499 py = pIn2;
<a name="l00500"></a>00500
<a name="l00501"></a>00501 <span class="comment">/* Increment the MAC count */</span>
<a name="l00502"></a>00502 count++;
<a name="l00503"></a>00503
<a name="l00504"></a>00504 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00505"></a>00505 blkCnt--;
<a name="l00506"></a>00506 }
<a name="l00507"></a>00507 }
<a name="l00508"></a>00508
<a name="l00509"></a>00509 <span class="comment">/* -------------------------- </span>
<a name="l00510"></a>00510 <span class="comment"> * Initializations of stage3 </span>
<a name="l00511"></a>00511 <span class="comment"> * -------------------------*/</span>
<a name="l00512"></a>00512
<a name="l00513"></a>00513 <span class="comment">/* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1] </span>
<a name="l00514"></a>00514 <span class="comment"> * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1] </span>
<a name="l00515"></a>00515 <span class="comment"> * .... </span>
<a name="l00516"></a>00516 <span class="comment"> * sum += x[srcALen-2] * y[0] + x[srcALen-1] * y[1] </span>
<a name="l00517"></a>00517 <span class="comment"> * sum += x[srcALen-1] * y[0] </span>
<a name="l00518"></a>00518 <span class="comment"> */</span>
<a name="l00519"></a>00519
<a name="l00520"></a>00520 <span class="comment">/* In this stage the MAC operations are decreased by 1 for every iteration. </span>
<a name="l00521"></a>00521 <span class="comment"> The count variable holds the number of MAC operations performed */</span>
<a name="l00522"></a>00522 count = srcBLen - 1u;
<a name="l00523"></a>00523
<a name="l00524"></a>00524 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00525"></a>00525 pSrc1 = ((pIn1 + <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>) - srcBLen) + 1u;
<a name="l00526"></a>00526 px = pSrc1;
<a name="l00527"></a>00527
<a name="l00528"></a>00528 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00529"></a>00529 py = pIn2;
<a name="l00530"></a>00530
<a name="l00531"></a>00531 <span class="comment">/* ------------------- </span>
<a name="l00532"></a>00532 <span class="comment"> * Stage3 process </span>
<a name="l00533"></a>00533 <span class="comment"> * ------------------*/</span>
<a name="l00534"></a>00534
<a name="l00535"></a>00535 <span class="keywordflow">while</span>(blockSize3 &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">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00541"></a>00541 k = count &gt;&gt; 2u;
<a name="l00542"></a>00542
<a name="l00543"></a>00543 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00544"></a>00544 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00545"></a>00545 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00546"></a>00546 {
<a name="l00547"></a>00547 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00548"></a>00548 <span class="comment">/* sum += x[srcALen - srcBLen + 4] * y[3] */</span>
<a name="l00549"></a>00549 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00550"></a>00550 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00551"></a>00551 <span class="comment">/* sum += x[srcALen - srcBLen + 3] * y[2] */</span>
<a name="l00552"></a>00552 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00553"></a>00553 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00554"></a>00554 <span class="comment">/* sum += x[srcALen - srcBLen + 2] * y[1] */</span>
<a name="l00555"></a>00555 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00556"></a>00556 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00557"></a>00557 <span class="comment">/* sum += x[srcALen - srcBLen + 1] * y[0] */</span>
<a name="l00558"></a>00558 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00559"></a>00559 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00560"></a>00560
<a name="l00561"></a>00561 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00562"></a>00562 k--;
<a name="l00563"></a>00563 }
<a name="l00564"></a>00564
<a name="l00565"></a>00565 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00566"></a>00566 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00567"></a>00567 k = count % 0x4u;
<a name="l00568"></a>00568
<a name="l00569"></a>00569 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00570"></a>00570 {
<a name="l00571"></a>00571 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00572"></a>00572 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#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) sum &lt;&lt; 32) +
<a name="l00573"></a>00573 ((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) * px++ * (*py++))) &gt;&gt; 32);
<a name="l00574"></a>00574
<a name="l00575"></a>00575 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00576"></a>00576 k--;
<a name="l00577"></a>00577 }
<a name="l00578"></a>00578
<a name="l00579"></a>00579 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00580"></a>00580 *pOut = sum &lt;&lt; 1;
<a name="l00581"></a>00581 <span class="comment">/* Destination pointer is updated according to the address modifier, inc */</span>
<a name="l00582"></a>00582 pOut += inc;
<a name="l00583"></a>00583
<a name="l00584"></a>00584 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00585"></a>00585 px = ++pSrc1;
<a name="l00586"></a>00586 py = pIn2;
<a name="l00587"></a>00587
<a name="l00588"></a>00588 <span class="comment">/* Decrement the MAC count */</span>
<a name="l00589"></a>00589 count--;
<a name="l00590"></a>00590
<a name="l00591"></a>00591 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00592"></a>00592 blockSize3--;
<a name="l00593"></a>00593 }
<a name="l00594"></a>00594
<a name="l00595"></a>00595 }
<a name="l00596"></a>00596
</pre></div></div>
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