func (b *Block) replaceUses(old, new *Value) {
	for _, v := range b.Values {
		for i, a := range v.Args {
			if a == old {
				v.SetArg(i, new)
			}
		}
	}
	for i, v := range b.ControlValues() {
		if v == old {
			b.ReplaceControl(i, new)
		}
	}
}

// moveTo moves v to dst, adjusting the appropriate Block.Values slices.
// The caller is responsible for ensuring that this is safe.

		}

		// Copy the control values - we need this so we can reduce the
		// uses property of these values later.
		controls := append(make([]*Value, 0, 2), b.ControlValues()...)

		// Load control values into registers.
		for i, v := range b.ControlValues() {
			if !s.values[v.ID].needReg {
				continue
			}
			if s.f.pass.debug > regDebug {
				fmt.Printf("  processing control %s\n", v.LongString())
			}

	if b.Aux != nil {
		s += html.EscapeString(fmt.Sprintf(" {%v}", b.Aux))
	}
	if t := b.AuxIntString(); t != "" {
		s += html.EscapeString(fmt.Sprintf(" [%v]", t))
	}
	for _, c := range b.ControlValues() {
		s += fmt.Sprintf(" %s", c.HTML())
	}
	if len(b.Succs) > 0 {
		s += " →" // right arrow
		for _, e := range b.Succs {
			c := e.b
			s += " " + c.HTML()
		}
	}

	"cmd/internal/obj/s390x"
)

// ssaMarkMoves marks any MOVXconst ops that need to avoid clobbering flags.
func ssaMarkMoves(s *ssagen.State, b *ssa.Block) {
	flive := b.FlagsLiveAtEnd
	for _, c := range b.ControlValues() {
		flive = c.Type.IsFlags() || flive
	}
	for i := len(b.Values) - 1; i >= 0; i-- {
		v := b.Values[i]
		if flive && v.Op == ssa.OpS390XMOVDconst {
			// The "mark" is any non-nil Aux value.

	"cmd/internal/obj/x86"
)

// ssaMarkMoves marks any MOVXconst ops that need to avoid clobbering flags.
func ssaMarkMoves(s *ssagen.State, b *ssa.Block) {
	flive := b.FlagsLiveAtEnd
	for _, c := range b.ControlValues() {
		flive = c.Type.IsFlags() || flive
	}
	for i := len(b.Values) - 1; i >= 0; i-- {
		v := b.Values[i]
		if flive && v.Op == ssa.Op386MOVLconst {
			// The "mark" is any non-nil Aux value.
			v.Aux = ssa.AuxMark

		for _, b := range f.Blocks {
			var b0 *Block
			if debug > 1 {
				b0 = new(Block)
				*b0 = *b
				b0.Succs = append([]Edge{}, b.Succs...) // make a new copy, not aliasing
			}
			for i, c := range b.ControlValues() {
				for c.Op == OpCopy {
					c = c.Args[0]
					b.ReplaceControl(i, c)
				}
			}
			if rb(b) {
				change = true
				if debug > 1 {