build: Fix xxhash x86 dispatch

[Wunkolo]

When compiling for a non-x86 platform, the x86-dispatch should not be included by explicitly checking the value of the OS_PLATFORM query-result.

[Wunkolo]

This was all that was needed for me to get Ymir compiling and running on a Windows-On-Arm machine(Thinkpad X13S):

Screen.Recording.2025-05-03.130749.mp4

[StrikerX3]

Can't believe I missed that detail. Thank you!

Are you running a Debug build in that video, by any chance? I'm surprised it runs that slow on an ARM device. Yep, seems to be a Debug build.

[Wunkolo]

Yep this was debug! I'm currently unable to compile on release mode for some reason. I reach a state during compilation where cl.exe just goes on seemingly forever and claims more and more memory before flushing back down a bit and then starts climbing up again endlessly despite stuff like LTO/IPO being disabled. I would likely have to figure out a way to cross-compile for release-mode builds.

Recording.2025-05-03.163940.mp4

When I kill the processes manually to see the build-errors it outputs, I find that this occurs when compiling sh2.cpp.obj, m68k.cpp.obj, and rewind_buffer.cpp.obj in particular. It compiles fine though in debug mode. It might have to do with the usage of FORCE_INLINE or FLATTEN:

Ymir/libs/ymir-core/include/ymir/util/inline.hpp

Lines 29 to 45 in febb5c5

	#if !defined(NDEBUG) || defined(DISABLE_FORCE_INLINE)
	#define FORCE_INLINE inline
	#define NO_INLINE
	#define FLATTEN
	#elif (defined(__GNUC__) || defined(__GNUG__) || defined(__clang__))
	#define FORCE_INLINE [[gnu::always_inline]] inline
	#define NO_INLINE [[gnu::noinline]]
	#define FLATTEN [[gnu::flatten]]
	#elif defined(_MSC_VER)
	#define FORCE_INLINE [[msvc::forceinline]] inline
	#define NO_INLINE [[msvc::noinline]]
	#define FLATTEN [[msvc::flatten]]
	#else
	#define FORCE_INLINE inline
	#define NO_INLINE
	#define FLATTEN
	#endif

[Wunkolo]

Removing FLATTEN from these files got it building in release-mode and working full-speed now! I'll sustain these changes locally since this seems like an arm64-MSVC compilation error.

Recording.2025-05-03.170914.mp4

[StrikerX3]

Interesting. I've faced a similar issue with GCC builds on Linux. It might be worth it revisiting the usage of FLATTEN then.