// next call.
var GCTestMoveStackOnNextCall = gcTestMoveStackOnNextCall

// For GCTestIsReachable, it's important that we do this as a call so
// escape analysis can see through it.
func GCTestIsReachable(ptrs ...unsafe.Pointer) (mask uint64) {
	return gcTestIsReachable(ptrs...)
}

// For GCTestPointerClass, it's important that we do this as a call so

		// scannable type.
		p := unsafe.Pointer(new(*int))
		all = append(all, p)
		if i%2 == 0 {
			half = append(half, p)
			want |= 1 << i
		}
	}

	got := runtime.GCTestIsReachable(all...)
	if got&want != want {
		// This is a serious bug - an object is live (due to the KeepAlive
		// call below), but isn't reported as such.
		t.Fatalf("live object not in reachable set; want %b, got %b", want, got)

// there's a preemption between this call and the next.
func gcTestMoveStackOnNextCall() {
	gp := getg()
	gp.stackguard0 = stackForceMove
}

// gcTestIsReachable performs a GC and returns a bit set where bit i
// is set if ptrs[i] is reachable.
func gcTestIsReachable(ptrs ...unsafe.Pointer) (mask uint64) {
	// This takes the pointers as unsafe.Pointers in order to keep
	// them live long enough for us to attach specials. After