diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 45b65da1e..35e093e73 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -327,6 +327,41 @@ if( NOT NO_ASM )
 	ENDMACRO( ADD_ASM_FILE )
 endif( NOT NO_ASM )
 
+# Decide on SSE setup
+
+set( SSE_MATTERS NO )
+
+# SSE only matters on 32-bit targets. We check compiler flags to know if we can do it.
+if( CMAKE_SIZEOF_VOID_P MATCHES "4" )
+	CHECK_CXX_COMPILER_FLAG( "-msse2 -mfpmath=sse" CAN_DO_MFPMATH )
+	CHECK_CXX_COMPILER_FLAG( -arch:SSE2 CAN_DO_ARCHSSE2 )
+	if( CAN_DO_MFPMATH )
+		set( SSE1_ENABLE "-msse -mfpmath=sse" )
+		set( SSE2_ENABLE "-msse2 -mfpmath=sse" )
+		set( SSE_MATTERS YES )
+	elseif( CAN_DO_ARCHSSE2 )
+		set( SSE1_ENABLE -arch:SSE )
+		set( SSE2_ENABLE -arch:SSE2 )
+		set( SSE_MATTERS YES )
+	endif( CAN_DO_MFPMATH )
+endif( CMAKE_SIZEOF_VOID_P MATCHES "4" )
+
+if( SSE_MATTERS )
+	if( WIN32 )
+		set( BACKPATCH 1 CACHE BOOL "Enable backpatching." )
+	else( WIN32 )
+		CHECK_FUNCTION_EXISTS(mprotect HAVE_MPROTECT)
+		if( HAVE_MPROTECT )
+			set( BACKPATCH 1 CACHE BOOL "Enable backpatching." )
+		else( HAVE_MPROTECT )
+			set( BACKPATCH 0 )
+		endif( HAVE_MPROTECT )
+	endif( WIN32 )
+	set( SSE 1 CACHE BOOL "Build SSE and SSE2 versions of key code." )
+else( SSE_MATTERS )
+	set( BACKPATCH 0 )
+endif( SSE_MATTERS )
+
 # Set up flags for GCC
 
 if( CMAKE_COMPILER_IS_GNUCXX )
@@ -422,6 +457,12 @@ if( NOT HAS_VA_COPY )
 	endif( HAS___VA_COPY )
 endif( NOT HAS_VA_COPY )
 
+# Flags
+
+if( BACKPATCH )
+	add_definitions( -DBACKPATCH )
+endif( BACKPATCH )
+
 # Update svnrevision.h
 
 add_custom_target( revision_check ALL
@@ -515,12 +556,18 @@ add_custom_command( OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/sc_man_scanner.h
 
 include_directories( ${CMAKE_CURRENT_BINARY_DIR} )
 
-if( CMAKE_SYSTEM_PROCESSOR MATCHES powerpc OR CMAKE_OSX_ARCHITECTURES MATCHES ppc )
+if( SSE_MATTERS )
+	if( SSE )
+		set( X86_SOURCES nodebuild_classify_sse2.cpp )
+		set_source_files_properties( nodebuild_classify_sse2.cpp PROPERTIES COMPILE_FLAGS "${SSE2_ENABLE}" )
+	else( SSE )
+		add_definitions( -DDISABLE_SSE )
+	endif( SSE )
+else( SSE_MATTERS )
+	add_definitions( -DDISABLE_SSE )
 	set( X86_SOURCES )
-	set( NOT_X86 ON )
-else( CMAKE_SYSTEM_PROCESSOR MATCHES powerpc OR CMAKE_OSX_ARCHITECTURES MATCHES ppc )
-	set( X86_SOURCES nodebuild_classify_sse2.cpp )
-endif( CMAKE_SYSTEM_PROCESSOR MATCHES powerpc OR CMAKE_OSX_ARCHITECTURES MATCHES ppc )
+endif( SSE_MATTERS )
+
 
 add_executable( zdoom WIN32
 	autostart.cpp
@@ -824,21 +871,12 @@ if( NOT WIN32 )
 		COMMAND chmod +x ${CMAKE_CURRENT_BINARY_DIR}/link-make
 		COMMAND /bin/sh -c ${CMAKE_CURRENT_BINARY_DIR}/link-make )
 endif( NOT WIN32 )
-
 if( CMAKE_COMPILER_IS_GNUCXX )
 	# GCC misoptimizes this file
 	set_source_files_properties( oplsynth/fmopl.cpp PROPERTIES COMPILE_FLAGS "-fno-tree-dominator-opts -fno-tree-fre" )
-	
-	# Compile this one file with SSE2 support.
-	set_source_files_properties( nodebuild_classify_sse2.cpp PROPERTIES COMPILE_FLAGS "-msse2 -mfpmath=sse" )
 
 	# Need to enable intrinsics for this file.
-	if( NOT NOT_X86 )
+	if( SSE_MATTERS )
 		set_source_files_properties( x86.cpp PROPERTIES COMPILE_FLAGS "-msse2 -mmmx" )
-	endif( NOT NOT_X86 )
+	endif( SSE_MATTERS )
 endif( CMAKE_COMPILER_IS_GNUCXX )
-
-if( MSVC )
-	# Compile this one file with SSE2 support.
-	set_source_files_properties( nodebuild_classify_sse2.cpp PROPERTIES COMPILE_FLAGS "/arch:SSE2" )
-endif( MSVC )
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 50af213b5..636d4d69f 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -1325,8 +1325,8 @@ void P_LoadSubsectors (MapData * map)
 		if ((size_t)subsectors[i].firstline >= maxseg)
 		{
 			Printf ("Subsector %d contains invalid segs %u-%u\n"
-				"The BSP will be rebuilt.\n", i, subsectors[i].firstline,
-				subsectors[i].firstline + subsectors[i].numlines - 1);
+				"The BSP will be rebuilt.\n", i, (unsigned)subsectors[i].firstline,
+				(unsigned)subsectors[i].firstline + subsectors[i].numlines - 1);
 			ForceNodeBuild = true;
 			delete[] nodes;
 			delete[] subsectors;
@@ -1336,7 +1336,7 @@ void P_LoadSubsectors (MapData * map)
 		{
 			Printf ("Subsector %d contains invalid segs %u-%u\n"
 				"The BSP will be rebuilt.\n", i, maxseg,
-				subsectors[i].firstline + subsectors[i].numlines - 1);
+				(unsigned)subsectors[i].firstline + subsectors[i].numlines - 1);
 			ForceNodeBuild = true;
 			delete[] nodes;
 			delete[] subsectors;