Add copy of opus library in deps/third_party.

opus/silk/float/energy_FLP.c

+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the 
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "SigProc_FLP.h"
+
+/* sum of squares of a silk_float array, with result as double */
+double silk_energy_FLP(
+    const silk_float    *data,
+    opus_int            dataSize
+)
+{
+    opus_int  i, dataSize4;
+    double   result;
+
+    /* 4x unrolled loop */
+    result = 0.0;
+    dataSize4 = dataSize & 0xFFFC;
+    for( i = 0; i < dataSize4; i += 4 ) {
+        result += data[ i + 0 ] * (double)data[ i + 0 ] +
+                  data[ i + 1 ] * (double)data[ i + 1 ] +
+                  data[ i + 2 ] * (double)data[ i + 2 ] +
+                  data[ i + 3 ] * (double)data[ i + 3 ];
+    }
+
+    /* add any remaining products */
+    for( ; i < dataSize; i++ ) {
+        result += data[ i ] * (double)data[ i ];
+    }
+
+    silk_assert( result >= 0.0 );
+    return result;
+}