GCC's -ffast-math behavior

[xunxun]

于 2012/2/9 17:21, Andrew Haley 写道:
> On 02/09/2012 08:33 AM, xunxun wrote:
>>          When using -ffast-math, gcc don't generate the math function
>> symbol: U _exp
> No, it doesn't.  Instead gcc uses the F2XM1 instruction.  Why would
> you want to call a library when gcc has an instruction to do the
> job?
>
> Andrew.
>
>
Because other math lib works faster than gcc itself (even with 
fastmath), and I want to use fastmath to make other caculation faster, too.

-- 
Best Regards,
xunxun