func typecheckrangeExpr(n *ir.RangeStmt) {
}

// type check assignment.
// if this assignment is the definition of a var on the left side,
// fill in the var's type.
func tcAssign(n *ir.AssignStmt) {
	if base.EnableTrace && base.Flag.LowerT {
		defer tracePrint("tcAssign", n)(nil)
	}

	if n.Y == nil {
		n.X = AssignExpr(n.X)
		return
	}

	lhs, rhs := []ir.Node{n.X}, []ir.Node{n.Y}
	assign(n, lhs, rhs)

		n.SetType(types.Types[types.TUINTPTR])
		return n

	case ir.OCONVNOP:
		n := n.(*ir.ConvExpr)
		n.X = Expr(n.X)
		return n

	// statements
	case ir.OAS:
		n := n.(*ir.AssignStmt)
		tcAssign(n)

		// Code that creates temps does not bother to set defn, so do it here.
		if n.X.Op() == ir.ONAME && ir.IsAutoTmp(n.X) {
			n.X.Name().Defn = n
		}
		return n

	case ir.OAS2:

		j -= 4
		sinSign, cosSign = !sinSign, !cosSign
	}
	if j > 1 {
		cosSign = !cosSign
	}

	zz := z * z
	cos = 1.0 - 0.5*zz + zz*zz*((((((_cos[0]*zz)+_cos[1])*zz+_cos[2])*zz+_cos[3])*zz+_cos[4])*zz+_cos[5])
	sin = z + z*zz*((((((_sin[0]*zz)+_sin[1])*zz+_sin[2])*zz+_sin[3])*zz+_sin[4])*zz+_sin[5])
	if j == 1 || j == 2 {
		sin, cos = cos, sin
	}
	if cosSign {
		cos = -cos
	}
	if sinSign {