add new file with AVX functions.

Does not fully support Linux at this time

diff --git a/libs/ardour/sse_functions_avx.cc b/libs/ardour/sse_functions_avx.cc
new file mode 100644 (file)
index 0000000..8c076aa
--- /dev/null
+++ b/libs/ardour/sse_functions_avx.cc
@@ -0,0 +1,120 @@
+/*
+    Copyright (C) 2007 Paul sDavis
+    Written by Sampo Savolainen
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <xmmintrin.h>
+#include <immintrin.h>
+#include "ardour/types.h"
+
+
+void
+x86_sse_avx_find_peaks(const ARDOUR::Sample* buf, ARDOUR::pframes_t nframes, float *min, float *max)
+{
+       __m256 current_max, current_min, work;
+
+       // Load max and min values into all four slots of the XMM registers
+       current_min = _mm256_set1_ps(*min);
+       current_max = _mm256_set1_ps(*max);
+
+       // Work input until "buf" reaches 16 byte alignment
+       while ( ((intptr_t)buf) % 32 != 0 && nframes > 0) {
+               
+               // Load the next float into the work buffer
+               work = _mm256_set1_ps(*buf);
+
+               current_min = _mm256_min_ps(current_min, work);
+               current_max = _mm256_max_ps(current_max, work);
+
+               buf++;
+               nframes--;
+       }
+
+        // use 64 byte prefetch for quadruple quads:
+               // load each 64 bytes into cash before processing
+        while (nframes >= 16) {
+#if defined(COMPILER_MSVC) || defined(COMPILER_MINGW)                                   
+                               _mm_prefetch(((char*)buf+64), _mm_hint(0) );  // A total guess! Assumed to be eqivalent to
+#else                                              // the line below but waiting to be tested !!
+                __builtin_prefetch(buf+64,0,0);
+#endif
+                work = _mm256_load_ps(buf);
+                current_min = _mm256_min_ps(current_min, work);
+                current_max = _mm256_max_ps(current_max, work);
+                buf+=8;
+                work = _mm256_load_ps(buf);
+                current_min = _mm256_min_ps(current_min, work);
+                current_max = _mm256_max_ps(current_max, work);
+                buf+=8;
+
+                nframes-=16;
+        }
+
+       // work through 32 bytes aligned buffers
+       while (nframes >= 8) {
+
+               work = _mm256_load_ps(buf);
+
+               current_min = _mm256_min_ps(current_min, work);
+               current_max = _mm256_max_ps(current_max, work);
+
+               buf+=8;
+               nframes-=8;
+       }
+
+       // work through the rest < 4 samples
+       while ( nframes > 0) {
+
+               // Load the next float into the work buffer
+               work = _mm256_set1_ps(*buf);
+
+               current_min = _mm256_min_ps(current_min, work);
+               current_max = _mm256_max_ps(current_max, work);
+
+               buf++;
+               nframes--;
+       }
+
+       // Find min & max value in current_max through shuffle tricks
+
+       work = current_min;
+       work =        _mm256_shuffle_ps (current_min, current_min, _MM_SHUFFLE(2, 3, 0, 1));
+       current_min = _mm256_min_ps (work, current_min);
+       work =        _mm256_shuffle_ps (current_min, current_min, _MM_SHUFFLE(1, 0, 3, 2));
+       current_min = _mm256_min_ps (work, current_min);
+       work =        _mm256_permute2f128_ps( current_min, current_min, 1);
+       current_min = _mm256_min_ps (work, current_min);
+
+       *min = current_min[0];
+
+       work = current_max;
+       work =        _mm256_shuffle_ps(current_max, current_max, _MM_SHUFFLE(2, 3, 0, 1));
+       current_max = _mm256_max_ps (work, current_max);
+       work =        _mm256_shuffle_ps(current_max, current_max, _MM_SHUFFLE(1, 0, 3, 2));
+       current_max = _mm256_max_ps (work, current_max);
+       work =        _mm256_permute2f128_ps( current_max, current_max, 1);
+       current_max = _mm256_max_ps (work, current_max);
+
+       *max = current_max[0];
+
+       // zero upper 128 bit of 256 bit ymm register to avoid penalties using non AVX instructions
+       _mm256_zeroupper ();
+}
+
+
+