{name: "NilCheck", argLength: 2, nilCheck: true},     // arg0=ptr, arg1=mem. Panics if arg0 is nil. Returns the ptr unmodified.

	// Pseudo-ops
	{name: "GetG", argLength: 1, zeroWidth: true}, // runtime.getg() (read g pointer). arg0=mem
	{name: "GetClosurePtr"},                       // get closure pointer from dedicated register
	{name: "GetCallerPC"},                         // for getcallerpc intrinsic

	return true
}

// This is the goroutine that runs all of the finalizers.
func runfinq() {
	var (
		frame    unsafe.Pointer
		framecap uintptr
		argRegs  int
	)

	gp := getg()
	lock(&finlock)
	fing = gp
	unlock(&finlock)

	for {
		lock(&finlock)
		fb := finq
		finq = nil
		if fb == nil {

func itabAdd(m *itab) {
	// Bugs can lead to calling this while mallocing is set,
	// typically because this is called while panicking.
	// Crash reliably, rather than only when we need to grow
	// the hash table.
	if getg().m.mallocing != 0 {
		throw("malloc deadlock")
	}

	t := itabTable
	if t.count >= 3*(t.size/4) { // 75% load factor
		// Grow hash table.
		// t2 = new(itabTableType) + some additional entries

	*runtime.CasGStatusAlwaysTrack = true

	mu.Lock1()

	// Start up a goroutine to wait on the lock.
	gc := make(chan *runtime.G)
	done := make(chan bool)
	go func() {
		gc <- runtime.Getg()

		for {
			mu.Lock2()
			mu.Unlock2()
			if <-done {
				return
			}
		}
	}()
	gp := <-gc

	// Set the block time high enough so that it will always show up, even