t.Skipf("skipping flaky test on %s; see golang.org/issue/18202", runtime.GOOS)
	}

	if runtime.GOARCH == "mips" || runtime.GOARCH == "mips64" {
		t.Skipf("skipping on %s", runtime.GOARCH)
	}

	attempts := 1000
	threads := 4

	// Restrict the number of attempts based on RLIMIT_NPROC.
	// Tediously, RLIMIT_NPROC was left out of the syscall package,
	// probably because it is not in POSIX.1, so we define it here.

	for {
		d := int64(-1)
		for d < 0 {
			k++
			nextTerm(k)
			d = extractDigit()
		}
		eliminateDigit(d)
		fmt.Printf("%c", d+'0')

		if i++; i%50 == 0 {
			fmt.Printf("\n")
			if i >= 1000 {
				break
			}
		}
	}

	fmt.Printf("\n%d calls; bit sizes: %d %d %d\n", runtime.NumCgoCall(), numer.Len(), accum.Len(), denom.Len())

	go func() {
		// We need the G continue running,
		// so the M has a chance to run this G.
		for {
			select {
			case <-stop:
				return
			case <-time.After(time.Millisecond * 100):
			}
		}
	}()
	defer close(stop)

	for i := 0; i < 1000; i++ {
		if !C.Ctid() {
			t.Fatalf("cgo has not locked OS thread")
		}
	}

type ScanToken rune

const (
	// Asm defines some two-character lexemes. We make up
	// a rune/ScanToken value for them - ugly but simple.
	LSH          ScanToken = -1000 - iota // << Left shift.
	RSH                                   // >> Logical right shift.
	ARR                                   // -> Used on ARM for shift type 3, arithmetic right shift.