use D3DCREATE_FPU_PRESERVE when initializing Direct3D to fix low frequency noise in DirectSound

src/Sound.cpp

@@ -27,10 +27,6 @@
 #include "Util.h"
 #include "Port.h"
 
-#ifdef _WIN32
-//#include <float.h>
-#endif
-
 #include "gb/gb_apu/Gb_Apu.h"
 #include "gb/gb_apu/Multi_Buffer.h"
 
@@ -451,12 +447,6 @@ static void remake_stereo_buffer()
 	if ( !ioMem )
 		return;
 	
-#ifdef _WIN32
-	// Direct3D might mess with FPU mode. Try uncommenting if more sound problems
-	// occur (also need to uncomment #include <float.h> above).
-	//_fpreset();
-#endif
-
 	// Clears pointers kept to old stereo_buffer
 	pcm [0].pcm.init();
 	pcm [1].pcm.init();

src/win32/Direct3D.cpp

@@ -303,6 +303,7 @@ bool Direct3DDisplay::initialize()
 		D3DADAPTER_DEFAULT,
 		D3DDEVTYPE_HAL,
 		theApp.m_pMainWnd->GetSafeHwnd(),
+		D3DCREATE_FPU_PRESERVE |
 		D3DCREATE_SOFTWARE_VERTEXPROCESSING,
 		&dpp,
 		&pDevice);