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Homework Problem 2.56:
Fill in the return value for the following procedure that tests whether its first argument is greater than or equal to its second. Assume the function f2u returns an unsigned 32-bit number having the same bit representation as its floating-point argument. You can assume that neither argument is NaN. The two flavors of zero: +0 and -0 are considered equal.
int float_ge(float x, float y)
{
unsigned ux = f2u(x);
unsigned uy = f2u(y);
/* Get the sign bits */
unsigned sx = ux >> 31;
unsigned sy = uy >> 31;
/* Give an expression using only ux, uy, sx, and sy */
return /* ... */ ;
}
Fill in the return value for the following procedure that tests whether its first argument is greater than or equal to its second. Assume the function f2u returns an unsigned 32-bit number having the same bit representation as its floating-point argument. You can assume that neither argument is NaN. The two flavors of zero: +0 and -0 are considered equal.
int float_ge(float x, float y)
{
unsigned ux = f2u(x);
unsigned uy = f2u(y);
/* Get the sign bits */
unsigned sx = ux >> 31;
unsigned sy = uy >> 31;
/* Give an expression using only ux, uy, sx, and sy */
return /* ... */ ;
}
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bohlee 2006-08-24
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mark
RiderOnStorm 2006-08-22
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To blue_zyb():
谢谢你回复。答案应该不对，没有考虑x=-0(100...0),y=+0(000...0)的情况。
另外，组合一些条件判断肯定能够解答这道题目，但我总觉得既然题目要你用一个表达式搞定，一定有更简洁的解法。
谢谢你回复。答案应该不对，没有考虑x=-0(100...0),y=+0(000...0)的情况。
另外，组合一些条件判断肯定能够解答这道题目，但我总觉得既然题目要你用一个表达式搞定，一定有更简洁的解法。
blue_zyb 2006-08-22
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return (sx < sy) || (sx == 0) && (ux >= uy) || (sx == 1) && (ux <= uy);
不知道对不对？:)
不知道对不对？:)
muroachanf 2006-08-22
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回家再看
