GCC beaten by ICC in stupid trig test!

[Robert Dewar]

Joe Buck wrote:

> On Tue, Mar 23, 2004 at 10:32:13PM -0500, Robert Dewar wrote:
> 
>>Well I don't know exactly what stuff is in -ffast-math, but I suspect it 
>>is a mistake to just think in terms of rounding error vs the mantissa 
>>length. 
>  
> Most of the optimizations have to do with ignoring the need to distinguish
> +0 and -0, or handle NaNs.
> 
>>For example, if -ffast-math is so sloppy as to consider
>>that (a+b)+c can be replaced by a+(b+c), then all bets are off.
> 
> That's why -ffast-math doesn't do that; such a transformation would be
> massively brain-damaged.

It would be a useful achievement in this thread if everyone understood
the truth of the above sentence. Clearly that is not the case from other
contributions to the thread :-)