Re: [about optimization]Is this a bug of gcc?

[Lionel B]

On Fri, 15 Feb 2008 20:05:06 +0800, mojianhao wrote:

> Hi experts,     I have a small test case, it got different result when
> compile with -O0 option and -O2 option. Is this a bug of gcc
> ?

[...]

Wow, that took some reformatting! What newsreader are you using?

Anyhow, no it's almost certainly not a bug. Read up on why floating point 
comparisons can give unexpected results. Here's a good place to start:

http://www.parashift.com/c++-faq-lite/newbie.html#faq-29.17

If you can get your head round that and want to dig a little deeper, try:

http://docs.sun.com/source/806-3568/ncg_goldberg.html

Regards,

-- 
Lionel B