9.1优化的主要种类 全局公共子表达式删除，复写传播，删除死代码 B x=ali];alialjl;a=x; =4*i 4*i X三 alt X三 a[t t 4*i =4* ts 4*j a[ts] to a[tsl alt] al] to a ts] =X t10= 4*j goto B2 a[tio]x goto B2
9.1 优化的主要种类 全局公共子表达式删除, 复写传播, 删除死代码 B5 x=a[i]; a[i]=a[j]; a[j]=x; t6 = 4 i x = a[t6 ] t7 = 4 i t8 = 4 j t9 = a[t8 ] a[t7 ] = t9 t10 = 4 j a[t10] = x goto B2 t6 = 4 i x = a[t6 ] t8 = 4 j t9 = a[t8 ] a[t6 ] = t9 a[t8 ] = x goto B2
9.1优化的主要种类 全局公共子表达式删除，复写传播，删除死代码 B x=ali];alialjl;a=x; =4*i t6= 4*i X= a[t2l X三 alt X- a[t t,alti] t 4*i =4* a[t]t, ts 4*j a[ts] a[ti] =X a[tsl a[t] B2 goto a[t]= to a ts] =X t10= 4*j goto B2 a[tio]x goto B2
9.1 优化的主要种类 全局公共子表达式删除, 复写传播, 删除死代码 B5 x=a[i]; a[i]=a[j]; a[j]=x; t6 = 4 i x = a[t6 ] t7 = 4 i t8 = 4 j t9 = a[t8 ] a[t7 ] = t9 t10 = 4 j a[t10] = x goto B2 t6 = 4 i x = a[t6 ] t8 = 4 j t9 = a[t8 ] a[t6 ] = t9 a[t8 ] = x goto B2 x = a[t2 ] t9 = a[t4 ] a[t2 ] = t9 a[t4 ] = x goto B2
9.1优化的主要种类 m一 n *n V= a[ti altz 飞 goto B, 4* alt goto B3 ifi>=j goto B B Bs B6
9.1 优化的主要种类 i = m −1 j = n t1 = 4 n v = a[t1] i = i + 1 t2 = 4 i t3 = a[t2] if t 3 < v goto B 2 B 1 B 2 j = j − 1 t 4 = 4 j t 5 = a[t 4 ] if t 5 > v goto B 3 if i >= j goto B 6 B 4 B 3 B 5 B 6
9.1优化的主要种类 全局公共子表达式删除，复写传播，删除死代码 B x=ali];alialjl;a=x; =4*i 4*i x a[tz] X三 alt X- a[t to altal t 4*i =4* alt]t, ts 4*j alts] atil =X a[tsl a[t] goto a[t]= to a ts] =X t10= 4*j goto B2 a[tio]x goto B2
9.1 优化的主要种类 全局公共子表达式删除, 复写传播, 删除死代码 B5 x=a[i]; a[i]=a[j]; a[j]=x; t6 = 4 i x = a[t6 ] t7 = 4 i t8 = 4 j t9 = a[t8 ] a[t7 ] = t9 t10 = 4 j a[t10] = x goto B2 t6 = 4 i x = a[t6 ] t8 = 4 j t9 = a[t8 ] a[t6 ] = t9 a[t8 ] = x goto B2 x = a[t2 ] t9 = a[t4 ] a[t2 ] = t9 a[t4 ] = x goto B2
9.1优化的主要种类 全局公共子表达式删除，复写传播，删除死代码 B x=ali];alialjl;a=x; =4*i =4*i x a[tl X三 alt X= a[t to altal t 4*i =4*】 a[t]t, ts 4*j alts] atil =X a[tsl a[t] goto B, a[t]= to a ts] =X t10= 4*j goto B2 alt]ts a[tio]x alti] =X goto B2 goto B
9.1 优化的主要种类 全局公共子表达式删除, 复写传播, 删除死代码 B5 x=a[i]; a[i]=a[j]; a[j]=x; t6 = 4 i x = a[t6 ] t7 = 4 i t8 = 4 j t9 = a[t8 ] a[t7 ] = t9 t10 = 4 j a[t10] = x goto B2 t6 = 4 i x = a[t6 ] t8 = 4 j t9 = a[t8 ] a[t6 ] = t9 a[t8 ] = x goto B2 x = a[t2 ] t9 = a[t4 ] a[t2 ] = t9 a[t4 ] = x goto B2 x = t3 a[t2 ] = t5 a[t4 ] = x goto B2