diff --git a/app/audio/audiovisualwaveform.cpp b/app/audio/audiovisualwaveform.cpp
index 4b44dd06a..22e169a2f 100644
--- a/app/audio/audiovisualwaveform.cpp
+++ b/app/audio/audiovisualwaveform.cpp
@@ -17,11 +17,9 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 ***/
-#if defined(__x86_64__) || defined(_M_X64) 
-#define x86_64
-#endif 
+#include <QtGlobal>
 
-#ifdef x86_64
+#ifdef Q_PROCESSOR_X86_64
 #include <xmmintrin.h>
 #endif
 
@@ -293,23 +291,38 @@ AudioVisualWaveform::Sample AudioVisualWaveform::SumSamples(const float *samples
   return summed_samples;
 }
 
-#ifdef x86_64
-void min_max_sse(float *a, int start, int end, float &min_val, float &max_val) {
-    // for time being just assume that length is always mod 4
-    __m128 max = _mm_loadu_ps(a + start); // load the first 4
-    __m128 min = _mm_loadu_ps(a + start); // load the first 4
-    for(int i = 4; i < end; i+=4)
-    {
-      __m128 cur = _mm_loadu_ps(a + start + i);
-      max = _mm_max_ps(max, cur);
-      min = _mm_min_ps(min, cur);
-    }
-    for (int i = 0; i < 3; i++) {
-        max = _mm_max_ps(max, _mm_shuffle_ps(max, max, 0x93));
-        min = _mm_min_ps(min, _mm_shuffle_ps(min, min, 0x93));
-    }
-    _mm_store_ss(&max_val, max);
-    _mm_store_ss(&min_val, min);
+#ifdef Q_PROCESSOR_X86_64
+void min_max_sse(float *a, int start, int end, float &min_val, float &max_val) 
+{
+  // load the first 4 elements of 'a' into min and max (they are 4 * 32 = 128 bits)
+  __m128 max = _mm_loadu_ps(a + start); 
+  __m128 min = _mm_loadu_ps(a + start);
+
+  // loop over 'a' and compare current elements with min and max 4 by 4. 
+  // we need to make sure we don't read out of boundaries should 'a' lenght be not mod. 4 
+  for(int i = 4; i < end-4; i+=4) {
+    __m128 cur = _mm_loadu_ps(a + start + i);
+    max = _mm_max_ps(max, cur);
+    min = _mm_min_ps(min, cur);
+  }
+  // so we read the last 4 (or less) elements in a safe manner.
+  __m128 cur = _mm_loadu_ps(a + end - 4);
+  max = _mm_max_ps(max, cur);
+  min = _mm_min_ps(min, cur);
+  // this potentially overlaps up to the last 3 elements but it's not an issue.
+
+  // min and max will contain 4 min and max. To get the absolute min and max 
+  // we need to compare the 4 values over themselves by shuffling each time.
+  for (int i = 0; i < 3; i++) {
+    max = _mm_max_ps(max, _mm_shuffle_ps(max, max, 0x93));
+    min = _mm_min_ps(min, _mm_shuffle_ps(min, min, 0x93));
+  }
+  // now min and max contain 4 identical items each representing min and max value respectively.
+
+  // and we store the first one into a float variable.
+  _mm_store_ss(&max_val, max);
+  _mm_store_ss(&min_val, min);
+  // I bet you don't find annotated low level code very often.
 }
 #endif
 
@@ -318,7 +331,7 @@ AudioVisualWaveform::Sample AudioVisualWaveform::SumSamples(SampleBufferPtr samp
   int channels = samples->audio_params().channel_count();
   AudioVisualWaveform::Sample summed_samples(channels);
 
-  #ifdef x86_64
+  #ifdef Q_PROCESSOR_X86_64
     for (int channel=0; channel<samples->audio_params().channel_count(); channel++) {
       min_max_sse(samples->data(channel), start_index, length, summed_samples[channel].min, summed_samples[channel].max);
     }