[PPL-devel] More floating point problems on the Alpha
Joseph S. Myers
joseph at codesourcery.com
Mon Sep 22 23:41:05 CEST 2008
On Mon, 22 Sep 2008, Joe Buck wrote:
> On Mon, Sep 22, 2008 at 09:56:30PM +0200, Abramo Bagnara wrote:
> > The problem come from the fact that for astonishing reasons 1.4e-45f is
> > not seen as 1.4e-45.
>
> Why is this astonishing? The smallest positive single-precision IEEE
> floating point number is roughly 1.175494e-38. Since user-specified
> numbers are rounded to the closest representable value, 1.4e-45f is
> a fancy way of typing zero.
The smallest subnormal value is approximately 1.40129846e-45F
(__FLT_DENORM_MIN__). The obvious conclusion is that subnormal support is
broken or disabled on Alpha by default.
--
Joseph S. Myers
joseph at codesourcery.com
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