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<h1>arm_conv_partial_fast_q15.c</h1> </div>
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<a href="arm__conv__partial__fast__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_partial_fast_q15.c </span>
<a name="l00009"></a>00009 <span class="comment">* </span>
<a name="l00010"></a>00010 <span class="comment">* Description: Fast Q15 Partial convolution. </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="l00056"></a><a class="code" href="group___partial_conv.html#ga1e4d43385cb62262a78c6752fe1fafb2">00056</a> <a class="code" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6" title="Error status returned by some functions in the library.">arm_status</a> <a class="code" href="group___partial_conv.html#ga1e4d43385cb62262a78c6752fe1fafb2" title="Partial convolution of Q15 sequences (fast version) for Cortex-M3 and Cortex-M4.">arm_conv_partial_fast_q15</a>(
<a name="l00057"></a>00057 <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="l00058"></a>00058 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>,
<a name="l00059"></a>00059 <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="l00060"></a>00060 uint32_t <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>,
<a name="l00061"></a>00061 <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="l00062"></a>00062 uint32_t firstIndex,
<a name="l00063"></a>00063 uint32_t numPoints)
<a name="l00064"></a>00064 {
<a name="l00065"></a>00065 <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="l00066"></a>00066 <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="l00067"></a>00067 <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="l00068"></a>00068 <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">/* Accumulator */</span>
<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> *px; <span class="comment">/* Intermediate inputA pointer */</span>
<a name="l00070"></a>00070 <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="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> *pSrc1, *pSrc2; <span class="comment">/* Intermediate pointers */</span>
<a name="l00072"></a>00072 <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;
<a name="l00073"></a>00073 uint32_t j, k, count, check, blkCnt;
<a name="l00074"></a>00074 int32_t blockSize1, blockSize2, blockSize3; <span class="comment">/* loop counters */</span>
<a name="l00075"></a>00075 <a class="code" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6" title="Error status returned by some functions in the library.">arm_status</a> <a class="code" href="arm__dotproduct__example__f32_8c.html#a88ccb294236ab22b00310c47164c53c3">status</a>; <span class="comment">/* status of Partial convolution */</span>
<a name="l00076"></a>00076 <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="l00077"></a>00077
<a name="l00078"></a>00078 <span class="comment">/* Check for range of output samples to be calculated */</span>
<a name="l00079"></a>00079 <span class="keywordflow">if</span>((firstIndex + numPoints) &gt; ((srcALen + (srcBLen - 1u))))
<a name="l00080"></a>00080 {
<a name="l00081"></a>00081 <span class="comment">/* Set status as ARM_MATH_ARGUMENT_ERROR */</span>
<a name="l00082"></a>00082 status = <a class="code" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a74897e18d4b8f62b12a7d8a01dd2bb35">ARM_MATH_ARGUMENT_ERROR</a>;
<a name="l00083"></a>00083 }
<a name="l00084"></a>00084 <span class="keywordflow">else</span>
<a name="l00085"></a>00085 {
<a name="l00086"></a>00086
<a name="l00087"></a>00087 <span class="comment">/* The algorithm implementation is based on the lengths of the inputs. */</span>
<a name="l00088"></a>00088 <span class="comment">/* srcB is always made to slide across srcA. */</span>
<a name="l00089"></a>00089 <span class="comment">/* So srcBLen is always considered as shorter or equal to srcALen */</span>
<a name="l00090"></a>00090 <span class="keywordflow">if</span>(srcALen &gt;= srcBLen)
<a name="l00091"></a>00091 {
<a name="l00092"></a>00092 <span class="comment">/* Initialization of inputA pointer */</span>
<a name="l00093"></a>00093 pIn1 = pSrcA;
<a name="l00094"></a>00094
<a name="l00095"></a>00095 <span class="comment">/* Initialization of inputB pointer */</span>
<a name="l00096"></a>00096 pIn2 = pSrcB;
<a name="l00097"></a>00097 }
<a name="l00098"></a>00098 <span class="keywordflow">else</span>
<a name="l00099"></a>00099 {
<a name="l00100"></a>00100 <span class="comment">/* Initialization of inputA pointer */</span>
<a name="l00101"></a>00101 pIn1 = pSrcB;
<a name="l00102"></a>00102
<a name="l00103"></a>00103 <span class="comment">/* Initialization of inputB pointer */</span>
<a name="l00104"></a>00104 pIn2 = pSrcA;
<a name="l00105"></a>00105
<a name="l00106"></a>00106 <span class="comment">/* srcBLen is always considered as shorter or equal to srcALen */</span>
<a name="l00107"></a>00107 j = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
<a name="l00108"></a>00108 srcBLen = <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>;
<a name="l00109"></a>00109 srcALen = j;
<a name="l00110"></a>00110 }
<a name="l00111"></a>00111
<a name="l00112"></a>00112 <span class="comment">/* Conditions to check which loopCounter holds </span>
<a name="l00113"></a>00113 <span class="comment"> * the first and last indices of the output samples to be calculated. */</span>
<a name="l00114"></a>00114 check = firstIndex + numPoints;
<a name="l00115"></a>00115 blockSize3 = ((int32_t) check - (int32_t) <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>);
<a name="l00116"></a>00116 blockSize3 = (blockSize3 &gt; 0) ? blockSize3 : 0;
<a name="l00117"></a>00117 blockSize1 = (((int32_t) srcBLen - 1) - (int32_t) firstIndex);
<a name="l00118"></a>00118 blockSize1 = (blockSize1 &gt; 0) ? ((check &gt; (srcBLen - 1u)) ? blockSize1 :
<a name="l00119"></a>00119 (int32_t) numPoints) : 0;
<a name="l00120"></a>00120 blockSize2 = (int32_t) check - ((blockSize3 + blockSize1) +
<a name="l00121"></a>00121 (int32_t) firstIndex);
<a name="l00122"></a>00122 blockSize2 = (blockSize2 &gt; 0) ? blockSize2 : 0;
<a name="l00123"></a>00123
<a name="l00124"></a>00124 <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="l00125"></a>00125 <span class="comment">/* The function is internally </span>
<a name="l00126"></a>00126 <span class="comment"> * divided into three stages according to the number of multiplications that has to be </span>
<a name="l00127"></a>00127 <span class="comment"> * taken place between inputA samples and inputB samples. In the first stage of the </span>
<a name="l00128"></a>00128 <span class="comment"> * algorithm, the multiplications increase by one for every iteration. </span>
<a name="l00129"></a>00129 <span class="comment"> * In the second stage of the algorithm, srcBLen number of multiplications are done. </span>
<a name="l00130"></a>00130 <span class="comment"> * In the third stage of the algorithm, the multiplications decrease by one </span>
<a name="l00131"></a>00131 <span class="comment"> * for every iteration. */</span>
<a name="l00132"></a>00132
<a name="l00133"></a>00133 <span class="comment">/* Set the output pointer to point to the firstIndex </span>
<a name="l00134"></a>00134 <span class="comment"> * of the output sample to be calculated. */</span>
<a name="l00135"></a>00135 pOut = pDst + firstIndex;
<a name="l00136"></a>00136
<a name="l00137"></a>00137 <span class="comment">/* -------------------------- </span>
<a name="l00138"></a>00138 <span class="comment"> * Initializations of stage1 </span>
<a name="l00139"></a>00139 <span class="comment"> * -------------------------*/</span>
<a name="l00140"></a>00140
<a name="l00141"></a>00141 <span class="comment">/* sum = x[0] * y[0] </span>
<a name="l00142"></a>00142 <span class="comment"> * sum = x[0] * y[1] + x[1] * y[0] </span>
<a name="l00143"></a>00143 <span class="comment"> * .... </span>
<a name="l00144"></a>00144 <span class="comment"> * sum = x[0] * y[srcBlen - 1] + x[1] * y[srcBlen - 2] +...+ x[srcBLen - 1] * y[0] </span>
<a name="l00145"></a>00145 <span class="comment"> */</span>
<a name="l00146"></a>00146
<a name="l00147"></a>00147 <span class="comment">/* In this stage the MAC operations are increased by 1 for every iteration. </span>
<a name="l00148"></a>00148 <span class="comment"> The count variable holds the number of MAC operations performed. </span>
<a name="l00149"></a>00149 <span class="comment"> Since the partial convolution starts from firstIndex </span>
<a name="l00150"></a>00150 <span class="comment"> Number of Macs to be performed is firstIndex + 1 */</span>
<a name="l00151"></a>00151 count = 1u + firstIndex;
<a name="l00152"></a>00152
<a name="l00153"></a>00153 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00154"></a>00154 px = pIn1;
<a name="l00155"></a>00155
<a name="l00156"></a>00156 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00157"></a>00157 pSrc2 = pIn2 + firstIndex;
<a name="l00158"></a>00158 py = pSrc2;
<a name="l00159"></a>00159
<a name="l00160"></a>00160 <span class="comment">/* ------------------------ </span>
<a name="l00161"></a>00161 <span class="comment"> * Stage1 process </span>
<a name="l00162"></a>00162 <span class="comment"> * ----------------------*/</span>
<a name="l00163"></a>00163
<a name="l00164"></a>00164 <span class="comment">/* For loop unrolling by 4, this stage is divided into two. */</span>
<a name="l00165"></a>00165 <span class="comment">/* First part of this stage computes the MAC operations less than 4 */</span>
<a name="l00166"></a>00166 <span class="comment">/* Second part of this stage computes the MAC operations greater than or equal to 4 */</span>
<a name="l00167"></a>00167
<a name="l00168"></a>00168 <span class="comment">/* The first part of the stage starts here */</span>
<a name="l00169"></a>00169 <span class="keywordflow">while</span>((count &lt; 4u) &amp;&amp; (blockSize1 &gt; 0))
<a name="l00170"></a>00170 {
<a name="l00171"></a>00171 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00172"></a>00172 sum = 0;
<a name="l00173"></a>00173
<a name="l00174"></a>00174 <span class="comment">/* Loop over number of MAC operations between </span>
<a name="l00175"></a>00175 <span class="comment"> * inputA samples and inputB samples */</span>
<a name="l00176"></a>00176 k = count;
<a name="l00177"></a>00177
<a name="l00178"></a>00178 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00179"></a>00179 {
<a name="l00180"></a>00180 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00181"></a>00181 sum = __SMLAD(*px++, *py--, sum);
<a name="l00182"></a>00182
<a name="l00183"></a>00183 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00184"></a>00184 k--;
<a name="l00185"></a>00185 }
<a name="l00186"></a>00186
<a name="l00187"></a>00187 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00188"></a>00188 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (sum &gt;&gt; 15);
<a name="l00189"></a>00189
<a name="l00190"></a>00190 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00191"></a>00191 py = ++pSrc2;
<a name="l00192"></a>00192 px = pIn1;
<a name="l00193"></a>00193
<a name="l00194"></a>00194 <span class="comment">/* Increment the MAC count */</span>
<a name="l00195"></a>00195 count++;
<a name="l00196"></a>00196
<a name="l00197"></a>00197 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00198"></a>00198 blockSize1--;
<a name="l00199"></a>00199 }
<a name="l00200"></a>00200
<a name="l00201"></a>00201 <span class="comment">/* The second part of the stage starts here */</span>
<a name="l00202"></a>00202 <span class="comment">/* The internal loop, over count, is unrolled by 4 */</span>
<a name="l00203"></a>00203 <span class="comment">/* To, read the last two inputB samples using SIMD: </span>
<a name="l00204"></a>00204 <span class="comment"> * y[srcBLen] and y[srcBLen-1] coefficients, py is decremented by 1 */</span>
<a name="l00205"></a>00205 py = py - 1;
<a name="l00206"></a>00206
<a name="l00207"></a>00207 <span class="keywordflow">while</span>(blockSize1 &gt; 0)
<a name="l00208"></a>00208 {
<a name="l00209"></a>00209 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00210"></a>00210 sum = 0;
<a name="l00211"></a>00211
<a name="l00212"></a>00212 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00213"></a>00213 k = count &gt;&gt; 2u;
<a name="l00214"></a>00214
<a name="l00215"></a>00215 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00216"></a>00216 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00217"></a>00217 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00218"></a>00218 {
<a name="l00219"></a>00219 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00220"></a>00220 <span class="comment">/* x[0], x[1] are multiplied with y[srcBLen - 1], y[srcBLen - 2] respectively */</span>
<a name="l00221"></a>00221 sum = __SMLADX(*<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="l00222"></a>00222 <span class="comment">/* x[2], x[3] are multiplied with y[srcBLen - 3], y[srcBLen - 4] respectively */</span>
<a name="l00223"></a>00223 sum = __SMLADX(*<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="l00224"></a>00224
<a name="l00225"></a>00225 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00226"></a>00226 k--;
<a name="l00227"></a>00227 }
<a name="l00228"></a>00228
<a name="l00229"></a>00229 <span class="comment">/* For the next MAC operations, the pointer py is used without SIMD </span>
<a name="l00230"></a>00230 <span class="comment"> * So, py is incremented by 1 */</span>
<a name="l00231"></a>00231 py = py + 1u;
<a name="l00232"></a>00232
<a name="l00233"></a>00233 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00234"></a>00234 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00235"></a>00235 k = count % 0x4u;
<a name="l00236"></a>00236
<a name="l00237"></a>00237 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00238"></a>00238 {
<a name="l00239"></a>00239 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00240"></a>00240 sum = __SMLAD(*px++, *py--, sum);
<a name="l00241"></a>00241
<a name="l00242"></a>00242 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00243"></a>00243 k--;
<a name="l00244"></a>00244 }
<a name="l00245"></a>00245
<a name="l00246"></a>00246 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00247"></a>00247 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (sum &gt;&gt; 15);
<a name="l00248"></a>00248
<a name="l00249"></a>00249 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00250"></a>00250 py = ++pSrc2 - 1u;
<a name="l00251"></a>00251 px = pIn1;
<a name="l00252"></a>00252
<a name="l00253"></a>00253 <span class="comment">/* Increment the MAC count */</span>
<a name="l00254"></a>00254 count++;
<a name="l00255"></a>00255
<a name="l00256"></a>00256 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00257"></a>00257 blockSize1--;
<a name="l00258"></a>00258 }
<a name="l00259"></a>00259
<a name="l00260"></a>00260 <span class="comment">/* -------------------------- </span>
<a name="l00261"></a>00261 <span class="comment"> * Initializations of stage2 </span>
<a name="l00262"></a>00262 <span class="comment"> * ------------------------*/</span>
<a name="l00263"></a>00263
<a name="l00264"></a>00264 <span class="comment">/* sum = x[0] * y[srcBLen-1] + x[1] * y[srcBLen-2] +...+ x[srcBLen-1] * y[0] </span>
<a name="l00265"></a>00265 <span class="comment"> * sum = x[1] * y[srcBLen-1] + x[2] * y[srcBLen-2] +...+ x[srcBLen] * y[0] </span>
<a name="l00266"></a>00266 <span class="comment"> * .... </span>
<a name="l00267"></a>00267 <span class="comment"> * sum = x[srcALen-srcBLen-2] * y[srcBLen-1] + x[srcALen] * y[srcBLen-2] +...+ x[srcALen-1] * y[0] </span>
<a name="l00268"></a>00268 <span class="comment"> */</span>
<a name="l00269"></a>00269
<a name="l00270"></a>00270 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00271"></a>00271 px = pIn1;
<a name="l00272"></a>00272
<a name="l00273"></a>00273 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00274"></a>00274 pSrc2 = pIn2 + (srcBLen - 1u);
<a name="l00275"></a>00275 py = pSrc2;
<a name="l00276"></a>00276
<a name="l00277"></a>00277 <span class="comment">/* Initialize inputB pointer of type q31 */</span>
<a name="l00278"></a>00278 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="l00279"></a>00279
<a name="l00280"></a>00280 <span class="comment">/* count is the index by which the pointer pIn1 to be incremented */</span>
<a name="l00281"></a>00281 count = 1u;
<a name="l00282"></a>00282
<a name="l00283"></a>00283
<a name="l00284"></a>00284 <span class="comment">/* -------------------- </span>
<a name="l00285"></a>00285 <span class="comment"> * Stage2 process </span>
<a name="l00286"></a>00286 <span class="comment"> * -------------------*/</span>
<a name="l00287"></a>00287
<a name="l00288"></a>00288 <span class="comment">/* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed. </span>
<a name="l00289"></a>00289 <span class="comment"> * So, to loop unroll over blockSize2, </span>
<a name="l00290"></a>00290 <span class="comment"> * srcBLen should be greater than or equal to 4 */</span>
<a name="l00291"></a>00291 <span class="keywordflow">if</span>(srcBLen &gt;= 4u)
<a name="l00292"></a>00292 {
<a name="l00293"></a>00293 <span class="comment">/* Loop unroll over blockSize2, by 4 */</span>
<a name="l00294"></a>00294 blkCnt = ((uint32_t) blockSize2 &gt;&gt; 2u);
<a name="l00295"></a>00295
<a name="l00296"></a>00296 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00297"></a>00297 {
<a name="l00298"></a>00298 <span class="comment">/* Set all accumulators to zero */</span>
<a name="l00299"></a>00299 acc0 = 0;
<a name="l00300"></a>00300 acc1 = 0;
<a name="l00301"></a>00301 acc2 = 0;
<a name="l00302"></a>00302 acc3 = 0;
<a name="l00303"></a>00303
<a name="l00304"></a>00304
<a name="l00305"></a>00305 <span class="comment">/* read x[0], x[1] samples */</span>
<a name="l00306"></a>00306 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="l00307"></a>00307 <span class="comment">/* read x[1], x[2] samples */</span>
<a name="l00308"></a>00308 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="l00309"></a>00309
<a name="l00310"></a>00310
<a name="l00311"></a>00311 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00312"></a>00312 k = srcBLen &gt;&gt; 2u;
<a name="l00313"></a>00313
<a name="l00314"></a>00314 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00315"></a>00315 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00316"></a>00316 <span class="keywordflow">do</span>
<a name="l00317"></a>00317 {
<a name="l00318"></a>00318 <span class="comment">/* Read the last two inputB samples using SIMD: </span>
<a name="l00319"></a>00319 <span class="comment"> * y[srcBLen - 1] and y[srcBLen - 2] */</span>
<a name="l00320"></a>00320 c0 = *(pb--);
<a name="l00321"></a>00321
<a name="l00322"></a>00322 <span class="comment">/* acc0 += x[0] * y[srcBLen - 1] + x[1] * y[srcBLen - 2] */</span>
<a name="l00323"></a>00323 acc0 = __SMLADX(x0, c0, acc0);
<a name="l00324"></a>00324
<a name="l00325"></a>00325 <span class="comment">/* acc1 += x[1] * y[srcBLen - 1] + x[2] * y[srcBLen - 2] */</span>
<a name="l00326"></a>00326 acc1 = __SMLADX(x1, c0, acc1);
<a name="l00327"></a>00327
<a name="l00328"></a>00328 <span class="comment">/* Read x[2], x[3] */</span>
<a name="l00329"></a>00329 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="l00330"></a>00330
<a name="l00331"></a>00331 <span class="comment">/* Read x[3], x[4] */</span>
<a name="l00332"></a>00332 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="l00333"></a>00333
<a name="l00334"></a>00334 <span class="comment">/* acc2 += x[2] * y[srcBLen - 1] + x[3] * y[srcBLen - 2] */</span>
<a name="l00335"></a>00335 acc2 = __SMLADX(x2, c0, acc2);
<a name="l00336"></a>00336
<a name="l00337"></a>00337 <span class="comment">/* acc3 += x[3] * y[srcBLen - 1] + x[4] * y[srcBLen - 2] */</span>
<a name="l00338"></a>00338 acc3 = __SMLADX(x3, c0, acc3);
<a name="l00339"></a>00339
<a name="l00340"></a>00340 <span class="comment">/* Read y[srcBLen - 3] and y[srcBLen - 4] */</span>
<a name="l00341"></a>00341 c0 = *(pb--);
<a name="l00342"></a>00342
<a name="l00343"></a>00343 <span class="comment">/* acc0 += x[2] * y[srcBLen - 3] + x[3] * y[srcBLen - 4] */</span>
<a name="l00344"></a>00344 acc0 = __SMLADX(x2, c0, acc0);
<a name="l00345"></a>00345
<a name="l00346"></a>00346 <span class="comment">/* acc1 += x[3] * y[srcBLen - 3] + x[4] * y[srcBLen - 4] */</span>
<a name="l00347"></a>00347 acc1 = __SMLADX(x3, c0, acc1);
<a name="l00348"></a>00348
<a name="l00349"></a>00349 <span class="comment">/* Read x[4], x[5] */</span>
<a name="l00350"></a>00350 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="l00351"></a>00351
<a name="l00352"></a>00352 <span class="comment">/* Read x[5], x[6] */</span>
<a name="l00353"></a>00353 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="l00354"></a>00354
<a name="l00355"></a>00355 <span class="comment">/* acc2 += x[4] * y[srcBLen - 3] + x[5] * y[srcBLen - 4] */</span>
<a name="l00356"></a>00356 acc2 = __SMLADX(x0, c0, acc2);
<a name="l00357"></a>00357
<a name="l00358"></a>00358 <span class="comment">/* acc3 += x[5] * y[srcBLen - 3] + x[6] * y[srcBLen - 4] */</span>
<a name="l00359"></a>00359 acc3 = __SMLADX(x1, c0, acc3);
<a name="l00360"></a>00360
<a name="l00361"></a>00361 } <span class="keywordflow">while</span>(--k);
<a name="l00362"></a>00362
<a name="l00363"></a>00363 <span class="comment">/* For the next MAC operations, SIMD is not used </span>
<a name="l00364"></a>00364 <span class="comment"> * So, the 16 bit pointer if inputB, py is updated */</span>
<a name="l00365"></a>00365 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="l00366"></a>00366 py = py + 1;
<a name="l00367"></a>00367
<a name="l00368"></a>00368 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00369"></a>00369 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00370"></a>00370 k = srcBLen % 0x4u;
<a name="l00371"></a>00371
<a name="l00372"></a>00372 <span class="keywordflow">if</span>(k == 1u)
<a name="l00373"></a>00373 {
<a name="l00374"></a>00374 <span class="comment">/* Read y[srcBLen - 5] */</span>
<a name="l00375"></a>00375 c0 = *(py);
<a name="l00376"></a>00376 <span class="preprocessor">#ifdef ARM_MATH_BIG_ENDIAN</span>
<a name="l00377"></a>00377 <span class="preprocessor"></span>
<a name="l00378"></a>00378 c0 = c0 &lt;&lt; 16;
<a name="l00379"></a>00379
<a name="l00380"></a>00380 <span class="preprocessor">#endif </span><span class="comment">/* #ifdef ARM_MATH_BIG_ENDIAN */</span>
<a name="l00381"></a>00381
<a name="l00382"></a>00382 <span class="comment">/* Read x[7] */</span>
<a name="l00383"></a>00383 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="l00384"></a>00384
<a name="l00385"></a>00385 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00386"></a>00386 acc0 = __SMLAD(x0, c0, acc0);
<a name="l00387"></a>00387 acc1 = __SMLAD(x1, c0, acc1);
<a name="l00388"></a>00388 acc2 = __SMLADX(x1, c0, acc2);
<a name="l00389"></a>00389 acc3 = __SMLADX(x3, c0, acc3);
<a name="l00390"></a>00390 }
<a name="l00391"></a>00391
<a name="l00392"></a>00392 <span class="keywordflow">if</span>(k == 2u)
<a name="l00393"></a>00393 {
<a name="l00394"></a>00394 <span class="comment">/* Read y[srcBLen - 5], y[srcBLen - 6] */</span>
<a name="l00395"></a>00395 c0 = *(pb);
<a name="l00396"></a>00396
<a name="l00397"></a>00397 <span class="comment">/* Read x[7], x[8] */</span>
<a name="l00398"></a>00398 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="l00399"></a>00399
<a name="l00400"></a>00400 <span class="comment">/* Read x[9] */</span>
<a name="l00401"></a>00401 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="l00402"></a>00402
<a name="l00403"></a>00403 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00404"></a>00404 acc0 = __SMLADX(x0, c0, acc0);
<a name="l00405"></a>00405 acc1 = __SMLADX(x1, c0, acc1);
<a name="l00406"></a>00406 acc2 = __SMLADX(x3, c0, acc2);
<a name="l00407"></a>00407 acc3 = __SMLADX(x2, c0, acc3);
<a name="l00408"></a>00408 }
<a name="l00409"></a>00409
<a name="l00410"></a>00410 <span class="keywordflow">if</span>(k == 3u)
<a name="l00411"></a>00411 {
<a name="l00412"></a>00412 <span class="comment">/* Read y[srcBLen - 5], y[srcBLen - 6] */</span>
<a name="l00413"></a>00413 c0 = *pb--;
<a name="l00414"></a>00414
<a name="l00415"></a>00415 <span class="comment">/* Read x[7], x[8] */</span>
<a name="l00416"></a>00416 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="l00417"></a>00417
<a name="l00418"></a>00418 <span class="comment">/* Read x[9] */</span>
<a name="l00419"></a>00419 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="l00420"></a>00420
<a name="l00421"></a>00421 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00422"></a>00422 acc0 = __SMLADX(x0, c0, acc0);
<a name="l00423"></a>00423 acc1 = __SMLADX(x1, c0, acc1);
<a name="l00424"></a>00424 acc2 = __SMLADX(x3, c0, acc2);
<a name="l00425"></a>00425 acc3 = __SMLADX(x2, c0, acc3);
<a name="l00426"></a>00426
<a name="l00427"></a>00427 <span class="comment">/* Read y[srcBLen - 7] */</span>
<a name="l00428"></a>00428 <span class="preprocessor">#ifdef ARM_MATH_BIG_ENDIAN</span>
<a name="l00429"></a>00429 <span class="preprocessor"></span>
<a name="l00430"></a>00430 c0 = (*pb);
<a name="l00431"></a>00431 c0 = (c0) &lt;&lt; 16;
<a name="l00432"></a>00432
<a name="l00433"></a>00433 <span class="preprocessor">#else</span>
<a name="l00434"></a>00434 <span class="preprocessor"></span>
<a name="l00435"></a>00435 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="l00436"></a>00436
<a name="l00437"></a>00437 <span class="preprocessor">#endif </span><span class="comment">/* #ifdef ARM_MATH_BIG_ENDIAN */</span>
<a name="l00438"></a>00438
<a name="l00439"></a>00439 <span class="comment">/* Read x[10] */</span>
<a name="l00440"></a>00440 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="l00441"></a>00441
<a name="l00442"></a>00442 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00443"></a>00443 acc0 = __SMLADX(x1, c0, acc0);
<a name="l00444"></a>00444 acc1 = __SMLAD(x2, c0, acc1);
<a name="l00445"></a>00445 acc2 = __SMLADX(x2, c0, acc2);
<a name="l00446"></a>00446 acc3 = __SMLADX(x3, c0, acc3);
<a name="l00447"></a>00447 }
<a name="l00448"></a>00448
<a name="l00449"></a>00449 <span class="comment">/* Store the results in the accumulators in the destination buffer. */</span>
<a name="l00450"></a>00450 <span class="preprocessor">#ifndef ARM_MATH_BIG_ENDIAN</span>
<a name="l00451"></a>00451 <span class="preprocessor"></span>
<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)++ = __PKHBT(acc0 &gt;&gt; 15, acc1 &gt;&gt; 15, 16);
<a name="l00453"></a>00453 *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(pOut)++ = __PKHBT(acc2 &gt;&gt; 15, acc3 &gt;&gt; 15, 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)++ = __PKHBT(acc1 &gt;&gt; 15, acc0 &gt;&gt; 15, 16);
<a name="l00458"></a>00458 *<a class="code" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248" title="definition to read/write two 16 bit values.">__SIMD32</a>(pOut)++ = __PKHBT(acc3 &gt;&gt; 15, acc2 &gt;&gt; 15, 16);
<a name="l00459"></a>00459
<a name="l00460"></a>00460 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_BIG_ENDIAN */</span>
<a name="l00461"></a>00461
<a name="l00462"></a>00462 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00463"></a>00463 px = pIn1 + (count * 4u);
<a name="l00464"></a>00464 py = pSrc2;
<a name="l00465"></a>00465 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="l00466"></a>00466
<a name="l00467"></a>00467 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
<a name="l00468"></a>00468 count++;
<a name="l00469"></a>00469
<a name="l00470"></a>00470 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00471"></a>00471 blkCnt--;
<a name="l00472"></a>00472 }
<a name="l00473"></a>00473
<a name="l00474"></a>00474 <span class="comment">/* If the blockSize2 is not a multiple of 4, compute any remaining output samples here. </span>
<a name="l00475"></a>00475 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00476"></a>00476 blkCnt = (uint32_t) blockSize2 % 0x4u;
<a name="l00477"></a>00477
<a name="l00478"></a>00478 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00479"></a>00479 {
<a name="l00480"></a>00480 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00481"></a>00481 sum = 0;
<a name="l00482"></a>00482
<a name="l00483"></a>00483 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00484"></a>00484 k = srcBLen &gt;&gt; 2u;
<a name="l00485"></a>00485
<a name="l00486"></a>00486 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00487"></a>00487 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00488"></a>00488 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00489"></a>00489 {
<a name="l00490"></a>00490 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00491"></a>00491 sum += ((<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="l00492"></a>00492 sum += ((<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="l00493"></a>00493 sum += ((<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#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) * px++ * *py--);
<a name="l00495"></a>00495
<a name="l00496"></a>00496 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00497"></a>00497 k--;
<a name="l00498"></a>00498 }
<a name="l00499"></a>00499
<a name="l00500"></a>00500 <span class="comment">/* If the srcBLen is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00501"></a>00501 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00502"></a>00502 k = srcBLen % 0x4u;
<a name="l00503"></a>00503
<a name="l00504"></a>00504 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00505"></a>00505 {
<a name="l00506"></a>00506 <span class="comment">/* Perform the multiply-accumulates */</span>
<a name="l00507"></a>00507 sum += ((<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="l00508"></a>00508
<a name="l00509"></a>00509 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00510"></a>00510 k--;
<a name="l00511"></a>00511 }
<a name="l00512"></a>00512
<a name="l00513"></a>00513 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00514"></a>00514 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (sum &gt;&gt; 15);
<a name="l00515"></a>00515
<a name="l00516"></a>00516 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00517"></a>00517 px = pIn1 + count;
<a name="l00518"></a>00518 py = pSrc2;
<a name="l00519"></a>00519
<a name="l00520"></a>00520 <span class="comment">/* Increment the pointer pIn1 index, count by 1 */</span>
<a name="l00521"></a>00521 count++;
<a name="l00522"></a>00522
<a name="l00523"></a>00523 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00524"></a>00524 blkCnt--;
<a name="l00525"></a>00525 }
<a name="l00526"></a>00526 }
<a name="l00527"></a>00527 <span class="keywordflow">else</span>
<a name="l00528"></a>00528 {
<a name="l00529"></a>00529 <span class="comment">/* If the srcBLen is not a multiple of 4, </span>
<a name="l00530"></a>00530 <span class="comment"> * the blockSize2 loop cannot be unrolled by 4 */</span>
<a name="l00531"></a>00531 blkCnt = (uint32_t) blockSize2;
<a name="l00532"></a>00532
<a name="l00533"></a>00533 <span class="keywordflow">while</span>(blkCnt &gt; 0u)
<a name="l00534"></a>00534 {
<a name="l00535"></a>00535 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00536"></a>00536 sum = 0;
<a name="l00537"></a>00537
<a name="l00538"></a>00538 <span class="comment">/* srcBLen number of MACS should be performed */</span>
<a name="l00539"></a>00539 k = <a class="code" href="arm__convolution__example__f32_8c.html#aea71286f498978c5ed3775609b974fc8">srcBLen</a>;
<a name="l00540"></a>00540
<a name="l00541"></a>00541 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00542"></a>00542 {
<a name="l00543"></a>00543 <span class="comment">/* Perform the multiply-accumulate */</span>
<a name="l00544"></a>00544 sum += ((<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="l00545"></a>00545
<a name="l00546"></a>00546 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00547"></a>00547 k--;
<a name="l00548"></a>00548 }
<a name="l00549"></a>00549
<a name="l00550"></a>00550 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00551"></a>00551 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (sum &gt;&gt; 15);
<a name="l00552"></a>00552
<a name="l00553"></a>00553 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00554"></a>00554 px = pIn1 + count;
<a name="l00555"></a>00555 py = pSrc2;
<a name="l00556"></a>00556
<a name="l00557"></a>00557 <span class="comment">/* Increment the MAC count */</span>
<a name="l00558"></a>00558 count++;
<a name="l00559"></a>00559
<a name="l00560"></a>00560 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00561"></a>00561 blkCnt--;
<a name="l00562"></a>00562 }
<a name="l00563"></a>00563 }
<a name="l00564"></a>00564
<a name="l00565"></a>00565
<a name="l00566"></a>00566 <span class="comment">/* -------------------------- </span>
<a name="l00567"></a>00567 <span class="comment"> * Initializations of stage3 </span>
<a name="l00568"></a>00568 <span class="comment"> * -------------------------*/</span>
<a name="l00569"></a>00569
<a name="l00570"></a>00570 <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="l00571"></a>00571 <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="l00572"></a>00572 <span class="comment"> * .... </span>
<a name="l00573"></a>00573 <span class="comment"> * sum += x[srcALen-2] * y[srcBLen-1] + x[srcALen-1] * y[srcBLen-2] </span>
<a name="l00574"></a>00574 <span class="comment"> * sum += x[srcALen-1] * y[srcBLen-1] </span>
<a name="l00575"></a>00575 <span class="comment"> */</span>
<a name="l00576"></a>00576
<a name="l00577"></a>00577 <span class="comment">/* In this stage the MAC operations are decreased by 1 for every iteration. </span>
<a name="l00578"></a>00578 <span class="comment"> The count variable holds the number of MAC operations performed */</span>
<a name="l00579"></a>00579 count = srcBLen - 1u;
<a name="l00580"></a>00580
<a name="l00581"></a>00581 <span class="comment">/* Working pointer of inputA */</span>
<a name="l00582"></a>00582 pSrc1 = (pIn1 + <a class="code" href="arm__convolution__example__f32_8c.html#ace48ed566e2cd6a680f0681192e6af28">srcALen</a>) - (srcBLen - 1u);
<a name="l00583"></a>00583 px = pSrc1;
<a name="l00584"></a>00584
<a name="l00585"></a>00585 <span class="comment">/* Working pointer of inputB */</span>
<a name="l00586"></a>00586 pSrc2 = pIn2 + (srcBLen - 1u);
<a name="l00587"></a>00587 pIn2 = pSrc2 - 1u;
<a name="l00588"></a>00588 py = pIn2;
<a name="l00589"></a>00589
<a name="l00590"></a>00590 <span class="comment">/* ------------------- </span>
<a name="l00591"></a>00591 <span class="comment"> * Stage3 process </span>
<a name="l00592"></a>00592 <span class="comment"> * ------------------*/</span>
<a name="l00593"></a>00593
<a name="l00594"></a>00594 <span class="comment">/* For loop unrolling by 4, this stage is divided into two. */</span>
<a name="l00595"></a>00595 <span class="comment">/* First part of this stage computes the MAC operations greater than 4 */</span>
<a name="l00596"></a>00596 <span class="comment">/* Second part of this stage computes the MAC operations less than or equal to 4 */</span>
<a name="l00597"></a>00597
<a name="l00598"></a>00598 <span class="comment">/* The first part of the stage starts here */</span>
<a name="l00599"></a>00599 j = count &gt;&gt; 2u;
<a name="l00600"></a>00600
<a name="l00601"></a>00601 <span class="keywordflow">while</span>((j &gt; 0u) &amp;&amp; (blockSize3 &gt; 0))
<a name="l00602"></a>00602 {
<a name="l00603"></a>00603 <span class="comment">/* Accumulator is made zero for every iteration */</span>
<a name="l00604"></a>00604 sum = 0;
<a name="l00605"></a>00605
<a name="l00606"></a>00606 <span class="comment">/* Apply loop unrolling and compute 4 MACs simultaneously. */</span>
<a name="l00607"></a>00607 k = count &gt;&gt; 2u;
<a name="l00608"></a>00608
<a name="l00609"></a>00609 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 MACs at a time. </span>
<a name="l00610"></a>00610 <span class="comment"> ** a second loop below computes MACs for the remaining 1 to 3 samples. */</span>
<a name="l00611"></a>00611 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00612"></a>00612 {
<a name="l00613"></a>00613 <span class="comment">/* x[srcALen - srcBLen + 1], x[srcALen - srcBLen + 2] are multiplied </span>
<a name="l00614"></a>00614 <span class="comment"> * with y[srcBLen - 1], y[srcBLen - 2] respectively */</span>
<a name="l00615"></a>00615 sum = __SMLADX(*<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="l00616"></a>00616 <span class="comment">/* x[srcALen - srcBLen + 3], x[srcALen - srcBLen + 4] are multiplied </span>
<a name="l00617"></a>00617 <span class="comment"> * with y[srcBLen - 3], y[srcBLen - 4] respectively */</span>
<a name="l00618"></a>00618 sum = __SMLADX(*<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
<a name="l00620"></a>00620 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00621"></a>00621 k--;
<a name="l00622"></a>00622 }
<a name="l00623"></a>00623
<a name="l00624"></a>00624 <span class="comment">/* For the next MAC operations, the pointer py is used without SIMD </span>
<a name="l00625"></a>00625 <span class="comment"> * So, py is incremented by 1 */</span>
<a name="l00626"></a>00626 py = py + 1u;
<a name="l00627"></a>00627
<a name="l00628"></a>00628 <span class="comment">/* If the count is not a multiple of 4, compute any remaining MACs here. </span>
<a name="l00629"></a>00629 <span class="comment"> ** No loop unrolling is used. */</span>
<a name="l00630"></a>00630 k = count % 0x4u;
<a name="l00631"></a>00631
<a name="l00632"></a>00632 <span class="keywordflow">while</span>(k &gt; 0u)
<a name="l00633"></a>00633 {
<a name="l00634"></a>00634 <span class="comment">/* sum += x[srcALen - srcBLen + 5] * y[srcBLen - 5] */</span>
<a name="l00635"></a>00635 sum = __SMLAD(*px++, *py--, sum);
<a name="l00636"></a>00636
<a name="l00637"></a>00637 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00638"></a>00638 k--;
<a name="l00639"></a>00639 }
<a name="l00640"></a>00640
<a name="l00641"></a>00641 <span class="comment">/* Store the result in the accumulator in the destination buffer. */</span>
<a name="l00642"></a>00642 *pOut++ = (<a class="code" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea" title="16-bit fractional data type in 1.15 format.">q15_t</a>) (sum &gt;&gt; 15);
<a name="l00643"></a>00643
<a name="l00644"></a>00644 <span class="comment">/* Update the inputA and inputB pointers for next MAC calculation */</span>
<a name="l00645"></a>00645 px = ++pSrc1;
<a name="l00646"></a>00646 py = pIn2;
<a name="l00647"></a>00647
<a name="l00648"></a>00648 <span class="comment">/* Decrement the MAC count */</span>
<a name="l00649"></a>00649 count--;
<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; 0)
<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 = count;
<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 = __SMLAD(*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>) (sum &gt;&gt; 15);
<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 MAC count */</span>
<a name="l00688"></a>00688 count--;
<a name="l00689"></a>00689
<a name="l00690"></a>00690 <span class="comment">/* Decrement the loop counter */</span>
<a name="l00691"></a>00691 blockSize3--;
<a name="l00692"></a>00692 }
<a name="l00693"></a>00693
<a name="l00694"></a>00694 <span class="comment">/* set status as ARM_MATH_SUCCESS */</span>
<a name="l00695"></a>00695 status = <a class="code" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a9f8b2a10bd827fb4600e77d455902eb0">ARM_MATH_SUCCESS</a>;
<a name="l00696"></a>00696 }
<a name="l00697"></a>00697
<a name="l00698"></a>00698 <span class="comment">/* Return to application */</span>
<a name="l00699"></a>00699 <span class="keywordflow">return</span> (status);
<a name="l00700"></a>00700
<a name="l00701"></a>00701 }
<a name="l00702"></a>00702
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