/* This file is dedicated to the public domain. */

// We get most of the libc functions from ucrtbase.dll, which comes with
// Windows, but for some reason a few of the intrinsic-y things are part of
// vcruntime, which does *not* come with Windows!!! We can statically link just
// that part but it adds ~12KiB of random useless bloat to our binary. So, let's
// just implement the handful of required things here instead. This is only for
// release/non-debug builds; we want the extra checks in Microsoft's CRT when
// debugging.
//
// Is it actually reasonable to have to do any of this? Of course not.

// TODO(opt): this feels like a sad implementation, can we do marginally better?
int memcmp(const void *x_, const void *y_, unsigned int sz) {
	const char *x = x_, *y = y_;
	for (unsigned int i = 0; i < sz; ++i) {
		if (x[i] > y[i]) return 1;
		if (x[i] < y[i]) return -1;
	}
	return 0;
}

void *memcpy(void *restrict x, const void *restrict y, unsigned int sz) {
#ifdef __clang__
	__asm__ volatile (
		"rep movsb\n" :
		"=D" (x), "=S" (y), "=c" (sz) :
		"0" (x), "1" (y), "2" (sz) :
		"memory"
	);
#else // terrible fallback just in case someone wants to use this with MSVC
	char *restrict xb = x; const char *restrict yb = y;
	for (unsigned int i = 0; i < sz; ++i) xb[i] = yb[i];
#endif
	return x;
}

int __stdcall _DllMainCRTStartup(void *inst, unsigned int reason,
		void *reserved) {
	return 1;
}

#ifdef __clang__
__attribute__((used))
#endif
int _fltused = 1;

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