关于RVDS浮点数转无符号数的问题。

只看该作者 · 2012-8-7 11:27

本帖最后由 ok2222991 于 2012-8-7 11:33 编辑

#include <stdio.h>
void fun()
{
float fset;

short s;
unsigned short us;

int i;
unsigned int ui;

int iset;

fset = -1.0;

s = fset;
us = fset;
i = fset;
ui = fset;

printf("f = %.2f, s = %d, us = %d, i = %d, ui = %d\n", fset, s, us, i, ui);

iset = -1;

s = iset;
us = iset;
i = iset;
ui = iset;

printf("iset = %d, s = %d, us = %d, i = %d, ui = %d\n", iset, s, us, i, ui);
}
int main(void)
{
fun();
}

只看该作者 · 2012-8-7 11:31

在RVDS中运行上面的程序，浮点数为负数的时候，浮点数转为无符号数，无符号数为0.

f = -1.00, s = -1, us = 0, i = -1, ui = 0
iset = -1, s = -1, us = 65535, i = -1, ui = -1

而用gcc和VC编译的结果是：

f = -1.00, s = -1, us = 65535, i = -1, ui = -1
iset = -1, s = -1, us = 65535, i = -1, ui = -1

有人能解释一下这是什么原因么？