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Re: Optimisation prevents overflow?


On Thu, Jul 19, 2007 at 11:49:56PM +0200, Daniel Franke wrote:
> On Thursday 19 July 2007 23:42:06 Brooks Moses wrote:
> > Yeah, I thought so at first, but those both have the same exponent range
> > IIRC, and certainly not enough to get up to an erroneous answer of 273
> > instead of 18 before it overflows.
> 
> As both, -ffloat-store and the external function (a CONTAINed function doesn't 
> work, inlining?) give consistent results, I'd assume that it's the right 
> ballpark, at least. It also hints that the usage of PRINT in the first loop 
> has the same effect?!

Paul Brook has corrected me.  The extra-precision registers _do_ have
enough extra precision that 273 is a reasonable answer for this theory.

Sorry for the confusion, then.  :)

So, yeah, -ffloat-store or -mfpmath=sse is the right answer.

- Brooks


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