func f19() {
	// dest temporary for channel receive.
	var z *byte

	if b {
		z = <-ch // ERROR "stack object .autotmp_[0-9]+ \*byte$"
	}
	z = <-ch
	z = <-ch // ERROR "live at call to chanrecv1: .autotmp_[0-9]+$"
	printbytepointer(z)
}

func f20() {
	// src temporary for channel send
	if b {
		ch <- byteptr() // ERROR "stack object .autotmp_[0-9]+ \*byte$"
	}
	ch <- byteptr()

	if t == nil {
		n.SetType(nil)
		return n
	}
	if !t.IsChan() {
		base.Errorf("invalid operation: %v (receive from non-chan type %v)", n, t)
		n.SetType(nil)
		return n
	}

	if !t.ChanDir().CanRecv() {
		base.Errorf("invalid operation: %v (receive from send-only type %v)", n, t)
		n.SetType(nil)
		return n
	}

	n.SetType(t.Elem())
	return n
}

// tcSPtr typechecks an OSPTR node.

	// copying needs to acquire channel locks to protect these
	// areas of the stack.
	activeStackChans bool
	// parkingOnChan indicates that the goroutine is about to
	// park on a chansend or chanrecv. Used to signal an unsafe point
	// for stack shrinking.
	parkingOnChan atomic.Bool
	// inMarkAssist indicates whether the goroutine is in mark assist.
	// Used by the execution tracer.
	inMarkAssist bool

String id=138
	data="runtime.traceStartReadCPU"
String id=139
	data="/usr/local/google/home/mknyszek/work/go-1/src/runtime/trace2cpu.go"
String id=140
	data="runtime.chanrecv1"
String id=141
	data="/usr/local/google/home/mknyszek/work/go-1/src/runtime/chan.go"
String id=142
	data="runtime.(*wakeableSleep).sleep"
String id=143
	data="runtime.traceStartReadCPU.func1"