// if n > len(frm) { n = len(frm) }
	nif := ir.NewIfStmt(base.Pos, nil, nil, nil)

	nif.Cond = ir.NewBinaryExpr(base.Pos, ir.OGT, nlen, ir.NewUnaryExpr(base.Pos, ir.OLEN, nr))
	nif.Body.Append(ir.NewAssignStmt(base.Pos, nlen, ir.NewUnaryExpr(base.Pos, ir.OLEN, nr)))
	l = append(l, nif)

	// if to.ptr != frm.ptr { memmove( ... ) }
	ne := ir.NewIfStmt(base.Pos, ir.NewBinaryExpr(base.Pos, ir.ONE, nto, nfrm), nil, nil)

			for i := lo; i < hi; i++ {
				nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
				leaf(i, nif)
				base.Pos = base.Pos.WithNotStmt()
				nif.Cond = typecheck.Expr(nif.Cond)
				nif.Cond = typecheck.DefaultLit(nif.Cond, nil)
				out.Append(nif)
				out = &nif.Else
			}
			return
		}

		half := lo + n/2
		nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
		nif.Cond = less(half)

	newLen := typecheck.TempAt(base.Pos, ir.CurFunc, types.Types[types.TINT])
	nodes.Append(ir.NewAssignStmt(base.Pos, newLen, ir.NewBinaryExpr(base.Pos, ir.OADD, oldLen, num)))

	// if uint(newLen) <= uint(oldCap)
	nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
	nuint := typecheck.Conv(newLen, types.Types[types.TUINT])
	scapuint := typecheck.Conv(oldCap, types.Types[types.TUINT])
	nif.Cond = ir.NewBinaryExpr(base.Pos, ir.OLE, nuint, scapuint)

	// freezes the counter when it reaches the value of 255. However, a range
	// of experiments showed that that decreases overall performance.
	o.append(ir.NewIfStmt(base.Pos,
		ir.NewBinaryExpr(base.Pos, ir.OEQ, counter, ir.NewInt(base.Pos, 0xff)),
		[]ir.Node{ir.NewAssignStmt(base.Pos, counter, ir.NewInt(base.Pos, 1))},