decomposeUserPhi(elem)
}

// MaxStruct is the maximum number of fields a struct
// can have and still be SSAable.
const MaxStruct = 4

// StructMakeOp returns the opcode to construct a struct with the
// given number of fields.
func StructMakeOp(nf int) Op {
	switch nf {
	case 0:
		return OpStructMake0
	case 1:
		return OpStructMake1
	case 2:
		return OpStructMake2
	case 3:

			addArg(e)
			pos = pos.WithNotStmt()
		}
		if at.NumFields() > 4 {
			panic(fmt.Errorf("Too many fields (%d, %d bytes), container=%s", at.NumFields(), at.Size(), container.LongString()))
		}
		a = makeOf(a, StructMakeOp(at.NumFields()), args)
		x.commonSelectors[sk] = a
		return a

	case types.TSLICE:
		addArg(x.rewriteSelectOrArg(pos, b, container, nil, m0, at.Elem().PtrTo(), rc.next(x.typs.BytePtr)))
		pos = pos.WithNotStmt()

			t := left.X.Type()
			nf := t.NumFields()
			idx := fieldIdx(left)

			// Grab old value of structure.
			old := s.expr(left.X)

			// Make new structure.
			new := s.newValue0(ssa.StructMakeOp(t.NumFields()), t)

			// Add fields as args.
			for i := 0; i < nf; i++ {
				if i == idx {
					new.AddArg(right)
				} else {