Architecture floating-point underflow information wanted

[Carlos O'Donell]

On Tue, Sep 25, 2012 at 8:52 AM, Joseph S. Myers
<joseph@codesourcery.com> wrote:
> As part of fixing bug 14047, I'd like information about how each glibc
> architecture (libc and ports) detects floating-point underflow.  (IEEE
> 754-2008 gives two options: "before rounding" (exponent would be below
> normal range if both exponent range and mantissa precision were unbounded)
> and "after rounding" (exponent of the rounded value would be below normal
> range if the exponent range were unbounded and values with all exponents
> had the same mantissa precision as for normal values).)

Thanks for the test case.

> I'm looking for information for the following architectures:
>
> s390-32, s390-64
> alpha
> am33
> hppa
> ia64
> m68k (classic)

hppa (64-bit PA-RISC 2.0) is after rounding according to the test.

The manual says:
~~~
Tininess is detected on a nonzero result which lies strictly between
+/-2^(Emin), when the result is rounded as if the exponent range were
unbounded.
~~~

Thus verified by what the manual says.

Cheers,
Carlos.