FP negation optimization

[Andrew Pinski]

On Feb 1, 2004, at 15:06, Chris Lattner wrote:

> On Sun, 1 Feb 2004, Richard Henderson wrote:
>
>> On Sun, Feb 01, 2004 at 02:50:31AM -0600, Chris Lattner wrote:
>>> Is '-0.0 - X' always guaranteed to be the same as '-X' with IEEE 
>>> math?
>>
>> No.  X == +0.0 differs.
>
> Are you sure?  It seems to work for me, at least on X86:

That is because GCC already optimizes it into -X but using a real old 
compiler
which does not optimizes it, 2.95.3,
-0x0.0000000000000p+0 -0x0.0000000000000p+0
0x0.0000000000000p+0 0x0.0000000000000p+0
is produce so it is correct optimization.


Thanks,
Andrew Pinski