q.As = AMOVD
	q.From.Type = obj.TYPE_MEM
	q.From.Sym = symtoc
	q.From.Name = obj.NAME_TOCREF
	q.To.Type = obj.TYPE_REG
	q.To.Reg = REGTMP

	q = obj.Appendp(q, c.newprog)
	q.As = p.As
	q.From = p.From
	q.To = p.To
	if p.From.Name != obj.NAME_NONE {
		q.From.Type = obj.TYPE_MEM
		q.From.Reg = REGTMP
		q.From.Name = obj.NAME_NONE
		q.From.Sym = nil

			f64 := p.From.Val.(float64)
			if math.Float64bits(f64) == 0 {
				p.As = AMOVV
				p.From.Type = obj.TYPE_REG
				p.From.Reg = REGZERO
				break
			}
			p.From.Type = obj.TYPE_MEM
			p.From.Sym = ctxt.Float64Sym(f64)
			p.From.Name = obj.NAME_EXTERN
			p.From.Offset = 0
		}
	}

	// Rewrite SUB constants into ADD.
	switch p.As {
	case ASUB:
		if p.From.Type == obj.TYPE_CONST {
			p.From.Offset = -p.From.Offset

		switch v.Op {
		case ssa.Op386LEAL1:
			p.From.Scale = 1
			if i == x86.REG_SP {
				r, i = i, r
			}
		case ssa.Op386LEAL2:
			p.From.Scale = 2
		case ssa.Op386LEAL4:
			p.From.Scale = 4
		case ssa.Op386LEAL8:
			p.From.Scale = 8
		}
		p.From.Type = obj.TYPE_MEM
		p.From.Reg = r
		p.From.Index = i
		ssagen.AddAux(&p.From, v)
		p.To.Type = obj.TYPE_REG
		p.To.Reg = v.Reg()

	p1.As = mov
	p1.From.Type = obj.TYPE_MEM
	p1.From.Sym = source.Sym
	p1.From.Name = obj.NAME_GOTREF
	p1.To.Type = obj.TYPE_REG
	p1.To.Reg = reg

	p2.As = p.As
	p2.From = p.From
	p2.To = p.To
	if from3 := p.GetFrom3(); from3 != nil {
		p2.AddRestSource(*from3)
	}
	if p.From.Name == obj.NAME_EXTERN {
		p2.From.Reg = reg
		p2.From.Name = obj.NAME_NONE
		p2.From.Sym = nil

			p.From.Type = obj.TYPE_MEM
			p.From.Reg = srcReg
			p.From.Offset = offset + 32
			p.To.Type = obj.TYPE_REG
			p.To.Reg = ppc64.REG_VS32

			p = s.Prog(ppc64.ALXV)
			p.From.Type = obj.TYPE_MEM
			p.From.Reg = srcReg
			p.From.Offset = offset + 48
			p.To.Type = obj.TYPE_REG
			p.To.Reg = ppc64.REG_VS33

			// generate 16 byte stores
			p = s.Prog(ppc64.ASTXV)
			p.From.Type = obj.TYPE_REG

	switch p.As {
	case AVMOVS:
		if p.From.Type == obj.TYPE_CONST {
			p.From.Type = obj.TYPE_MEM
			p.From.Sym = c.ctxt.Int32Sym(p.From.Offset)
			p.From.Name = obj.NAME_EXTERN
			p.From.Offset = 0
		}

	case AVMOVD:
		if p.From.Type == obj.TYPE_CONST {
			p.From.Type = obj.TYPE_MEM
			p.From.Sym = c.ctxt.Int64Sym(p.From.Offset)
			p.From.Name = obj.NAME_EXTERN
			p.From.Offset = 0
		}

	case AVMOVQ:

		i := v.Args[1].Reg()
		p := s.Prog(s390x.AMOVD)
		p.From.Scale = 1
		if i == s390x.REGSP {
			r, i = i, r
		}
		p.From.Type = obj.TYPE_ADDR
		p.From.Reg = r
		p.From.Index = i
		ssagen.AddAux(&p.From, v)
		p.To.Type = obj.TYPE_REG
		p.To.Reg = v.Reg()
	case ssa.OpS390XMOVDaddr:
		p := s.Prog(s390x.AMOVD)
		p.From.Type = obj.TYPE_ADDR
		p.From.Reg = v.Args[0].Reg()
		ssagen.AddAux(&p.From, v)

	{AADD, C_LCON, C_REG, C_REG, 13, 8, 0, LFROM, 0, C_SBIT},
	{AADD, C_LCON, C_NONE, C_REG, 13, 8, 0, LFROM, 0, C_SBIT},
	{AAND, C_LCON, C_REG, C_REG, 13, 8, 0, LFROM, 0, C_SBIT},
	{AAND, C_LCON, C_NONE, C_REG, 13, 8, 0, LFROM, 0, C_SBIT},
	{AORR, C_LCON, C_REG, C_REG, 13, 8, 0, LFROM, 0, C_SBIT},
	{AORR, C_LCON, C_NONE, C_REG, 13, 8, 0, LFROM, 0, C_SBIT},
	{AMVN, C_LCON, C_NONE, C_REG, 13, 8, 0, LFROM, 0, 0},

		case "linux":
			// Copied from golang.org/x/sys/unix/dev_linux.go.
			major := uint32((dev & 0x00000000000fff00) >> 8)
			major |= uint32((dev & 0xfffff00000000000) >> 32)
			minor := uint32((dev & 0x00000000000000ff) >> 0)
			minor |= uint32((dev & 0x00000ffffff00000) >> 12)
			h.Devmajor, h.Devminor = int64(major), int64(minor)
		case "darwin", "ios":
			// Copied from golang.org/x/sys/unix/dev_darwin.go.

}

// Flow marks a flow indicating that the 'to' span depends on the 'from' span.
// Flow should be called while the 'to' span is in progress.
func Flow(ctx context.Context, from *Span, to *Span) {
	tc, ok := getTraceContext(ctx)
	if !ok || from == nil || to == nil {
		return
	}

	id := tc.t.getNextFlowID()
	tc.t.writeEvent(&format.Event{
		Name:     from.name + " -> " + to.name,
		Category: "flow",
		ID:       id,