版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/FZHvampire/article/details/83825721
int saturating_add(int x,int y){
unsigned int tot=x+y;
int len=(sizeof(int)<<3)-1;
unsigned int flag=!((((x>>len)^(y>>len))&1) | !(((x>>len)^(tot>>len))&1)); //判断是否溢出
flag=~flag+1;
x=x>>len;
printf("%x\n",(tot|flag)-(flag&((unsigned int)x^(1<<len))));
}
typedef unsigned float_bits;
float_bits float_absval(float_bits f){
int len=(sizeof(int)<<3)-1;
float_bits o=(1<<len)&f;
float_bits a=(-1)<<24;
float_bits b=(a&(f<<1));
float_bits c=!(a^b); //阶数是否为全1
float_bits d=!(!(f<<9)); //尾数是否不为0
float_bits flag=c&d;
o=(flag<<len)&o; //符号位应该的值
f=(~(1<<len))&f; //将符号位置0
printf("%x\n",f|o);
}
typedef unsigned float_bits;
float_bits float_i2f(int i){
if(!i) return (float_bits)0;
int len=(sizeof(int)<<3)-1;
float_bits o=(1<<len)&(float_bits)i;
float_bits num=(~(1<<len))&(float_bits)i; //i的绝对值
if(o) num=o-num;
int dest=31;
float_bits ans=0,e=0;
while(!((1<<dest)&num)) --dest; //最高位1的位置
if(dest>23&&(num&1<<(dest-23))) num+=(1<<(dest-24)); //处理向偶数舍入
dest=31;while(!((1<<dest)&num)) --dest;
/*-------处理尾数--------*/
ans=(float_bits)num&(~(1<<dest));
if(dest>23) ans=ans>>(dest-23);
else ans=ans<<(23-dest);
/*-------处理阶数--------*/
e=127+dest;
ans|=(e<<23);
/*-------处理符号--------*/
if(o) ans|=(1<<len);
return ans;
}
}