func (c *mProfCycleHolder) read() (cycle uint32) {
	v := c.value.Load()
	cycle = v >> 1
	return cycle
}

// setFlushed sets the flushed flag. It returns the current cycle count and the
// previous value of the flushed flag.
func (c *mProfCycleHolder) setFlushed() (cycle uint32, alreadyFlushed bool) {
	for {
		prev := c.value.Load()
		cycle = prev >> 1
		alreadyFlushed = (prev & 0x1) != 0

	// TODO: get rid of reorderBuffer. See CL 23460044.
	rb := reorderBuffer{}
	rb.init(f, src)
	for {
		// Load segment into reorder buffer.
		rb.setFlusher(dst[nDst:], flushTransform)
		end := decomposeSegment(&rb, nSrc, atEOF)
		if end < 0 {
			return nDst, nSrc, errs[-end]
		}
		nDst = len(dst) - len(rb.out)
		nSrc = end

		// Next quickSpan.
		end = rb.nsrc

	// TODO: get rid of reorderBuffer. See CL 23460044.
	rb := reorderBuffer{}
	rb.init(f, src)
	for {
		// Load segment into reorder buffer.
		rb.setFlusher(dst[nDst:], flushTransform)
		end := decomposeSegment(&rb, nSrc, atEOF)
		if end < 0 {
			return nDst, nSrc, errs[-end]
		}
		nDst = len(dst) - len(rb.out)
		nSrc = end

		// Next quickSpan.
		end = rb.nsrc

func (f Form) IsNormal(b []byte) bool {
	src := inputBytes(b)
	ft := formTable[f]
	bp, ok := ft.quickSpan(src, 0, len(b), true)
	if ok {
		return true
	}
	rb := reorderBuffer{f: *ft, src: src, nsrc: len(b)}
	rb.setFlusher(nil, cmpNormalBytes)
	for bp < len(b) {
		rb.out = b[bp:]
		if bp = decomposeSegment(&rb, bp, true); bp < 0 {
			return false
		}
		bp, _ = rb.f.quickSpan(rb.src, bp, len(b), true)
	}
	return true
}

func (f Form) IsNormal(b []byte) bool {
	src := inputBytes(b)
	ft := formTable[f]
	bp, ok := ft.quickSpan(src, 0, len(b), true)
	if ok {
		return true
	}
	rb := reorderBuffer{f: *ft, src: src, nsrc: len(b)}
	rb.setFlusher(nil, cmpNormalBytes)
	for bp < len(b) {
		rb.out = b[bp:]
		if bp = decomposeSegment(&rb, bp, true); bp < 0 {
			return false
		}
		bp, _ = rb.f.quickSpan(rb.src, bp, len(b), true)
	}
	return true
}

	rb.ss = 0
}

func (rb *reorderBuffer) initString(f Form, src string) {
	rb.f = *formTable[f]
	rb.src.setString(src)
	rb.nsrc = len(src)
	rb.ss = 0
}

func (rb *reorderBuffer) setFlusher(out []byte, f func(*reorderBuffer) bool) {
	rb.out = out
	rb.flushF = f
}

// reset discards all characters from the buffer.
func (rb *reorderBuffer) reset() {
	rb.nrune = 0
	rb.nbyte = 0
}

	rb.ss = 0
}

func (rb *reorderBuffer) initString(f Form, src string) {
	rb.f = *formTable[f]
	rb.src.setString(src)
	rb.nsrc = len(src)
	rb.ss = 0
}

func (rb *reorderBuffer) setFlusher(out []byte, f func(*reorderBuffer) bool) {
	rb.out = out
	rb.flushF = f
}

// reset discards all characters from the buffer.
func (rb *reorderBuffer) reset() {
	rb.nrune = 0
	rb.nbyte = 0
}