Add denormal protection to Fifowriter thread

include/Mixer.h

@@ -25,6 +25,14 @@
 #ifndef _MIXER_H
 #define _MIXER_H
 
+// denormals stripping
+#ifdef __SSE__
+#include <xmmintrin.h>
+#endif
+#ifdef __SSE3__
+#include <pmmintrin.h>
+#endif
+
 #include "lmmsconfig.h"
 
 #ifndef LMMS_USE_3RDPARTY_LIBSRC

src/core/Mixer.cpp

@@ -902,6 +902,15 @@ Mixer::fifoWriter::fifoWriter( Mixer* mixer, fifo * _fifo ) :
 	m_fifo( _fifo ),
 	m_writing( true )
 {
+	// set denormal protection for this thread
+	#ifdef __SSE3__
+	/* DAZ flag */
+	_MM_SET_DENORMALS_ZERO_MODE( _MM_DENORMALS_ZERO_ON );
+	#endif
+	#ifdef __SSE__
+	/* FTZ flag */
+	_MM_SET_FLUSH_ZERO_MODE( _MM_FLUSH_ZERO_ON );
+	#endif
 }