另例:(1)PROD:=0 2I:=1 (3)T1:于4 (4)T2:=a0-4 (5)T3:=12[T1 (6)T4:=4*I (7)T5:=b0-4 (8)T6:=T5[TI4 (9)17:=T3*T6 (10)PROD: -PROD+ T7 (11)I:=Ⅰ+1 (12)ifI≤20goto(3) 进行:(1)删除多余运算,代码外提 (2)强度削弱 (3)变换循环控制条件,复写传播,合并已知量 (4)删除无用赋值另例:(1)PROD := 0 (2)I := 1 (3)T1 := 4 * I (4)T2 := a0 – 4 (5)T3 := T2[T1] (6)T4 := 4 * I (7)T5 := b0 – 4 (8)T6 := T5[T4] (9)T7 := T3 * T6 (10)PROD := PROD + T7 (11)I := I + 1 (12)if I ≤ 20 goto (3) 进行:(1)删除多余运算,代码外提 (2)强度削弱 (3)变换循环控制条件,复写传播,合并已知量 (4)删除无用赋值