memprofilerate    = flag.Int64("memprofilerate", 0, "set runtime.MemProfileRate to `rate`")
	benchmarkFlag     = flag.String("benchmark", "", "set to 'mem' or 'cpu' to enable phase benchmarking")
	benchmarkFileFlag = flag.String("benchmarkprofile", "", "emit phase profiles to `base`_phase.{cpu,mem}prof")

	flagW ternaryFlag
	FlagW = new(bool) // the -w flag, computed in main from flagW
)

	// to derive the mayNeedNorm bit later. This may trigger normalization
	// overeagerly, but it will not do so in the common case. The end result
	// is another 10% saving on BenchmarkProfile for the common case.
	var combinedInfoBits info
	for i := 0; i < len(s); {
		v, sz := trie.lookupString(s[i:])
		if sz == 0 {
			b = append(b, s[k:i]...)
			b = append(b, "\ufffd"...)
			k = len(s)