Fix architecture detection on Windows in Makefile, bump SAVEGAMEVER

$PROCESSOR_ARCHITECTURE seems to contain the architecture of the host,
but we need the architecture the current MinGW shell is targeting.
$MINGW_CHOST seems to be just that, and on my system it's either
i686-w64-mingw32 (mingw32.exe) or x86_64-w64-mingw32 (mingw64.exe)
(No idea what it looks like for Windows on ARM...)

As fixing this would otherwise break existing savegames, I bumped the
SAVEGAMEVER to "YQ2-4" and added a quirk for older savegameversions:
On Windows i386 savegames that contain "AMD64" instead of "i386" as
architecture are also accepted.
(For YQ2-1 this didn't seem necessary, apparently "i386" was hardcoded)

Makefile

@@ -31,6 +31,13 @@ endif
 
 # Detect the architecture
 ifeq ($(YQ2_OSTYPE), Windows)
+ifdef MINGW_CHOST
+ifeq ($(MINGW_CHOST), x86_64-w64-mingw32)
+YQ2_ARCH ?= x86_64
+else # i686-w64-mingw32
+YQ2_ARCH ?= i386
+endif
+else # windows, but MINGW_CHOST not defined
 ifdef PROCESSOR_ARCHITEW6432
 # 64 bit Windows
 YQ2_ARCH ?= $(PROCESSOR_ARCHITEW6432)
@@ -38,6 +45,7 @@ else
 # 32 bit Windows
 YQ2_ARCH ?= $(PROCESSOR_ARCHITECTURE)
 endif
+endif # windows but MINGW_CHOST not defined
 else
 # Normalize some abiguous YQ2_ARCH strings
 YQ2_ARCH ?= $(shell uname -m | sed -e 's/i.86/i386/' -e 's/amd64/x86_64/' -e 's/^arm.*/arm/')
@@ -120,13 +128,12 @@ endif
 
 # ----------
 
-# If we're building with gcc for i386 let's define -ffloat-store.
+# Using the default x87 float math on 32bit x86 causes rounding trouble
-# This helps the old and crappy x87 FPU to produce correct values.
+# -ffloat-store could work around that, but the better solution is to
-# Would be nice if Clang had something comparable.
+# just enforce SSE - every x86 CPU since Pentium3 supports that
+# and this should even improve the performance on old CPUs
 ifeq ($(YQ2_ARCH), i386)
-ifeq ($(COMPILER), gcc)
+override CFLAGS += -msse -mfpmath=sse
-override CFLAGS += -ffloat-store
-endif
 endif
 
 # Force SSE math on x86_64. All sane compilers should do this

src/savegame/savegame.c

@@ -51,7 +51,7 @@
 * load older savegames. This should be bumped if the files
 * in tables/ are changed, otherwise strange things may happen.
 */
-#define SAVEGAMEVER "YQ2-3"
+#define SAVEGAMEVER "YQ2-4"
 
 
 /*
@@ -829,84 +829,85 @@ ReadGame(const char *filename)
 	fread(str_os, sizeof(str_os), 1, f);
 	fread(str_arch, sizeof(str_arch), 1, f);
 
-	if (!strcmp(str_ver, SAVEGAMEVER))
+	static const struct {
-	{
+		const char* verstr;
-		save_ver = 3;
+		int vernum;
+	} version_mappings[] = {
+		{"YQ2-1", 1},
+		{"YQ2-2", 2},
+		{"YQ2-3", 3},
+		{"YQ2-4", 4},
+	};
 
-		if (strcmp(str_game, GAMEVERSION))
+	for (i=0; i < sizeof(version_mappings)/sizeof(version_mappings[0]); ++i)
+	{
+		if (strcmp(version_mappings[i].verstr, str_ver) == 0)
 		{
-			fclose(f);
+			save_ver = version_mappings[i].vernum;
-			gi.error("Savegame from an other game.so.\n");
+			break;
-		}
-		else if (strcmp(str_os, YQ2OSTYPE))
-		{
-			fclose(f);
-			gi.error("Savegame from an other os.\n");
-		}
-		else if (strcmp(str_arch, YQ2ARCH))
-		{
-			fclose(f);
-			gi.error("Savegame from an other architecure.\n");
 		}
 	}
-	else if (!strcmp(str_ver, "YQ2-2"))
+	
-	{
+	if (save_ver == 0) // not found in mappings table
-		save_ver = 2;
-
-		if (strcmp(str_game, GAMEVERSION))
-		{
-			fclose(f);
-			gi.error("Savegame from an other game.so.\n");
-		}
-		else if (strcmp(str_os, YQ2OSTYPE))
-		{
-			fclose(f);
-			gi.error("Savegame from an other os.\n");
-		}
-		else if (strcmp(str_arch, YQ2ARCH))
-		{
-			fclose(f);
-			gi.error("Savegame from an other architecure.\n");
-		}
-	}
-	else if (!strcmp(str_ver, "YQ2-1"))
-	{
-		save_ver = 1;
-
-		if (strcmp(str_game, GAMEVERSION))
-		{
-			fclose(f);
-			gi.error("Savegame from an other game.so.\n");
-		}
-		else if (strcmp(str_os, YQ2OSTYPE_1))
-		{
-			fclose(f);
-			gi.error("Savegame from an other os.\n");
-		}
-
-		if (!strcmp(str_os, "Windows"))
-		{
-			/* Windows was forced to i386 */
-			if (strcmp(str_arch, "i386"))
-			{
-				fclose(f);
-				gi.error("Savegame from an other architecure.\n");
-			}
-		}
-		else
-		{
-			if (strcmp(str_arch, YQ2ARCH_1))
-			{
-				fclose(f);
-				gi.error("Savegame from an other architecure.\n");
-			}
-		}
-	}
-	else
 	{
 		fclose(f);
 		gi.error("Savegame from an incompatible version.\n");
 	}
+	else if (save_ver == 1)
+	{
+		if (strcmp(str_game, GAMEVERSION) != 0)
+		{
+			fclose(f);
+			gi.error("Savegame from an other game.so.\n");
+		}
+		else if (strcmp(str_os, YQ2OSTYPE_1) != 0)
+		{
+			fclose(f);
+			gi.error("Savegame from an other os.\n");
+		}
+
+#ifdef _WIN32
+		/* Windows was forced to i386 */
+		if (strcmp(str_arch, "i386") != 0)
+		{
+			fclose(f);
+			gi.error("Savegame from another architecture.\n");
+		}
+#else
+		if (strcmp(str_arch, YQ2ARCH_1) != 0)
+		{
+			fclose(f);
+			gi.error("Savegame from another architecture.\n");
+		}
+#endif
+	}
+	else // all newer savegame versions
+	{
+		if (strcmp(str_game, GAMEVERSION) != 0)
+		{
+			fclose(f);
+			gi.error("Savegame from another game.so.\n");
+		}
+		else if (strcmp(str_os, YQ2OSTYPE) != 0)
+		{
+			fclose(f);
+			gi.error("Savegame from another os.\n");
+		}
+		else if (strcmp(str_arch, YQ2ARCH) != 0)
+		{
+#if defined(_WIN32) && (defined(__i386__) || defined(_M_IX86))
+			// before savegame version "YQ2-4" (and after version 1),
+			// the official Win32 binaries accidentally had the YQ2ARCH "AMD64"
+			// instead of "i386" set due to a bug in the Makefile.
+			// This quirk allows loading those savegames anyway
+			if (save_ver >= 4 || strcmp(str_arch, "AMD64") != 0)
+#endif
+			{
+				fclose(f);
+				gi.error("Savegame from another architecture.\n");
+			}
+		}
+	}
 
 	g_edicts = gi.TagMalloc(game.maxentities * sizeof(g_edicts[0]), TAG_GAME);
 	globals.edicts = g_edicts;