TEXT runtime·asmstdcall(SB),NOSPLIT,$16
	MOVQ	SP, AX
	ANDQ	$~15, SP	// alignment as per Windows requirement
	MOVQ	AX, 8(SP)
	MOVQ	CX, 0(SP)	// asmcgocall will put first argument into CX.

	MOVQ	libcall_fn(CX), AX
	MOVQ	libcall_args(CX), SI
	MOVQ	libcall_n(CX), CX

	// SetLastError(0).
	MOVQ	0x30(GS), DI
	MOVL	$0, 0x68(DI)

	SUBQ	$(const_maxArgs*8), SP	// room for args

	// Fast version, do not store args on the stack.

	if resetLibcall {
		mp.libcallsp = 0
	}
	return mp.libcall.r1
}

//go:nosplit
func stdcall0(fn stdFunction) uintptr {
	mp := getg().m
	mp.libcall.n = 0
	mp.libcall.args = 0
	return stdcall(fn)
}

//go:nosplit
//go:cgo_unsafe_args
func stdcall1(fn stdFunction, a0 uintptr) uintptr {
	mp := getg().m
	mp.libcall.n = 1

//go:nosplit
//go:cgo_unsafe_args
func doMmap(addr, n, prot, flags, fd, off uintptr) (uintptr, uintptr) {
	var libcall libcall
	libcall.fn = uintptr(unsafe.Pointer(&libc_mmap))
	libcall.n = 6
	libcall.args = uintptr(noescape(unsafe.Pointer(&addr)))
	asmcgocall(unsafe.Pointer(&asmsysvicall6x), unsafe.Pointer(&libcall))
	return libcall.r1, libcall.err
}

//go:nosplit
func munmap(addr unsafe.Pointer, n uintptr) {

	freelink    *m // on sched.freem
	trace       mTraceState

	// these are here because they are too large to be on the stack
	// of low-level NOSPLIT functions.
	libcall    libcall
	libcallpc  uintptr // for cpu profiler
	libcallsp  uintptr
	libcallg   guintptr
	winsyscall winlibcall // stores syscall parameters on windows

	vdsoSP uintptr // SP for traceback while in VDSO call (0 if not in call)

// rewind it into the CALL instruction.)
// If gp.m.libcall{g,pc,sp} information is available, it uses that information in preference to
// the pc/sp/lr passed in.
func tracebacktrap(pc, sp, lr uintptr, gp *g) {
	if gp.m.libcallsp != 0 {
		// We're in C code somewhere, traceback from the saved position.
		traceback1(gp.m.libcallpc, gp.m.libcallsp, 0, gp.m.libcallg.ptr(), 0)
		return
	}
	traceback1(pc, sp, lr, gp, unwindTrap)

	}
	if !isShrinkStackSafe(gp) {
		throw("shrinkstack at bad time")
	}
	// Check for self-shrinks while in a libcall. These may have
	// pointers into the stack disguised as uintptrs, but these
	// code paths should all be nosplit.
	if gp == getg().m.curg && gp.m.libcallsp != 0 {
		throw("shrinking stack in libcall")
	}

	if debug.gcshrinkstackoff > 0 {
		return
	}
	f := findfunc(gp.startpc)

		u.initAt(mp.curg.syscallpc, mp.curg.syscallsp, 0, mp.curg, unwindSilentErrors)
	} else if usesLibcall() && mp.libcallg != 0 && mp.libcallpc != 0 && mp.libcallsp != 0 {
		// Libcall, i.e. runtime syscall on windows.
		// Collect Go stack that leads to the call.
		u.initAt(mp.libcallpc, mp.libcallsp, 0, mp.libcallg.ptr(), unwindSilentErrors)
	} else if mp != nil && mp.vdsoSP != 0 {
		// VDSO call, e.g. nanotime1 on Linux.

		releasem(mp)
		return false
	}
	status := readgstatus(gp)
	if status&^_Gscan != _Grunning || gp.syscallsp != 0 {
		releasem(mp)
		return false
	}
	if GOOS == "windows" && mp.libcallsp != 0 {
		releasem(mp)
		return false
	}
	releasem(mp)
	return true
}

// shouldPushSigpanic reports whether pc should be used as sigpanic's