Tidy up some extensions and remove some ifdefs

Since this codebase is already extremely nonportable, I've decided to
relax the obsessive ifdef-else-error usage around all the extensions.
From now on, if there's no alternative to using an extension, we can
just use that extension. If it's possible to do something in a
relatively portable way, we can still try to do that in order to make
the code somewhat reusable, in contexts where that makes sense.

I also decided to use langext.h for naked functions and tail calls. If
that's used in another codebase build with a different compiler, those
just won't work, but that's fine. The benefit is really just that
there's less ceremony in places where those are used, because it's
likely there'll be a few more such places in the future, and it gets
annoying reading all the double-underscore stuff all over the place.

I still kind of want to do something about all the _WIN32 ifdefs too,
but I've realised that doing so will lead to almost nothing actually
being built on Linux. Then again, none of it currently runs on Linux so
I guess that's a moot point. Will worry about it later, anyway.

1 files changed, 0 insertions, 4 deletions

diff --git a/src/inputhud.c b/src/inputhud.c
index fbcbe79..6cff487 100644
--- a/src/inputhud.c
+++ b/src/inputhud.c
@@ -150,16 +150,12 @@ static inline int bsf(uint x) {
 	// doing a straight bsf (e.g. via BitScanForward or __builtin_ctz) creates
 	// a false dependency on many CPUs, which compilers don't understand somehow
 	int ret = 0;
-#if defined(__GNUC__) || defined(__clang__)
 	__asm volatile (
 		"bsf %0, %1\n"
 		: "+r" (ret)
 		: "r" (x)
 	);
 	return ret;
-#else
-#error need some sort of inline asm, or a non-broken(!) bitscan intrinsic
-#endif
 }
 
 // IMPORTANT: these things must all match the button order in engineapi.h