diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9332e4919..d4da7e7ce 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -449,6 +449,22 @@ else( SSE_MATTERS )
 	set( BACKPATCH 0 )
 endif( SSE_MATTERS )
 
+if( X64 )
+	set( HAVE_MMX 1 )
+else( X64 )
+	set( SAFE_CMAKE_C_FLAGS ${CMAKE_C_FLAGS} )
+
+	if( ZD_CMAKE_COMPILER_IS_GNUCXX_COMPATIBLE )
+		set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mmmx")
+	endif( ZD_CMAKE_COMPILER_IS_GNUCXX_COMPATIBLE )
+
+	CHECK_CXX_SOURCE_COMPILES("#include <mmintrin.h>
+		int main(void) { __m64 v = _m_from_int(0); }"
+		HAVE_MMX)
+
+	set( CMAKE_C_FLAGS ${SAFE_CMAKE_C_FLAGS} )
+endif( X64 )
+
 # Set up flags for GCC
 
 if( ZD_CMAKE_COMPILER_IS_GNUCXX_COMPATIBLE )
@@ -581,10 +597,6 @@ endif( NOT DYN_FLUIDSYNTH )
 
 # Start defining source files for ZDoom
 set( PLAT_WIN32_SOURCES
-	gl/hqnx_asm/hq2x_asm.cpp
-	gl/hqnx_asm/hq3x_asm.cpp
-	gl/hqnx_asm/hq4x_asm.cpp
-	gl/hqnx_asm/hqnx_asm_Image.cpp
 	win32/eaxedit.cpp
 	win32/fb_d3d9.cpp
 	win32/fb_d3d9_wipe.cpp
@@ -668,6 +680,25 @@ else( WIN32 )
 	set( OTHER_SYSTEM_SOURCES ${PLAT_WIN32_SOURCES} ${PLAT_OSX_SOURCES} ${PLAT_COCOA_SOURCES} )
 endif( WIN32 )
 
+if( HAVE_MMX )
+	add_definitions( -DHAVE_MMX=1 )
+
+	set( SYSTEM_SOURCES ${SYSTEM_SOURCES}
+		gl/hqnx_asm/hq2x_asm.cpp
+		gl/hqnx_asm/hq3x_asm.cpp
+		gl/hqnx_asm/hq4x_asm.cpp
+		gl/hqnx_asm/hqnx_asm_Image.cpp)
+
+	if( ZD_CMAKE_COMPILER_IS_GNUCXX_COMPATIBLE )
+		set_source_files_properties(
+			gl/hqnx_asm/hq2x_asm.cpp
+			gl/hqnx_asm/hq3x_asm.cpp
+			gl/hqnx_asm/hq4x_asm.cpp
+			gl/textures/gl_hqresize.cpp
+			PROPERTIES COMPILE_FLAGS "-mmmx" )
+	endif( ZD_CMAKE_COMPILER_IS_GNUCXX_COMPATIBLE )
+endif( HAVE_MMX )
+
 if( NOT ASM_SOURCES )
 	set( ASM_SOURCES "" )
 endif( NOT ASM_SOURCES )
diff --git a/src/gl/system/gl_menu.cpp b/src/gl/system/gl_menu.cpp
index 41304be0f..d4688cfd1 100644
--- a/src/gl/system/gl_menu.cpp
+++ b/src/gl/system/gl_menu.cpp
@@ -57,7 +57,7 @@ CUSTOM_CVAR (Float, vid_contrast, 1.f, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)
 // when they are actually valid.
 void gl_SetupMenu()
 {
-#ifndef _MSC_VER
+#ifndef HAVE_MMX
 	FOptionValues **opt = OptionValues.CheckKey("HqResizeModes");
 	if (opt != NULL) 
 	{
diff --git a/src/gl/textures/gl_hqresize.cpp b/src/gl/textures/gl_hqresize.cpp
index 621f444bc..261f66e6a 100644
--- a/src/gl/textures/gl_hqresize.cpp
+++ b/src/gl/textures/gl_hqresize.cpp
@@ -40,13 +40,13 @@
 #include "gl/textures/gl_texture.h"
 #include "c_cvars.h"
 #include "gl/hqnx/hqx.h"
-#ifdef _MSC_VER
+#ifdef HAVE_MMX
 #include "gl/hqnx_asm/hqnx_asm.h"
 #endif
 
 CUSTOM_CVAR(Int, gl_texture_hqresize, 0, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
 {
-#ifdef _MSC_VER
+#ifdef HAVE_MMX
 	if (self < 0 || self > 9)
 #else
 	if (self < 0 || self > 6)
@@ -186,8 +186,7 @@ static unsigned char *scaleNxHelper( void (*scaleNxFunction) ( uint32* , uint32*
 	return newBuffer;
 }
 
-// [BB] hqnx scaling is only supported with the MS compiler.
-#ifdef _MSC_VER
+#ifdef HAVE_MMX
 static unsigned char *hqNxAsmHelper( void (*hqNxFunction) ( int*, unsigned char*, int, int, int ),
 							  const int N,
 							  unsigned char *inputBuffer,
@@ -285,7 +284,7 @@ unsigned char *gl_CreateUpsampledTextureBuffer ( const FTexture *inputTexture, u
 		outWidth = inWidth;
 		outHeight = inHeight;
 		int type = gl_texture_hqresize;
-#ifdef _MSC_VER
+#ifdef HAVE_MMX
 		// ASM-hqNx does not preserve the alpha channel so fall back to C-version for such textures
 		if (!hasAlpha && type > 3 && type <= 6)
 		{
@@ -307,7 +306,7 @@ unsigned char *gl_CreateUpsampledTextureBuffer ( const FTexture *inputTexture, u
 			return hqNxHelper( &hq3x_32, 3, inputBuffer, inWidth, inHeight, outWidth, outHeight );
 		case 6:
 			return hqNxHelper( &hq4x_32, 4, inputBuffer, inWidth, inHeight, outWidth, outHeight );
-#ifdef _MSC_VER
+#ifdef HAVE_MMX
 		case 7:
 			return hqNxAsmHelper( &HQnX_asm::hq2x_32, 2, inputBuffer, inWidth, inHeight, outWidth, outHeight );
 		case 8: