[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Gcl-devel] Re: new and improved results.
From: |
Camm Maguire |
Subject: |
[Gcl-devel] Re: new and improved results. |
Date: |
05 Jun 2002 17:25:42 -0400 |
Greetings!
address@hidden writes:
> the awk fix for libbfd and libiberty is ok.
great!
> the test for awk isn't, you need to test for nawk first
why? If awk is not available, should then test for nawk.
> if you are on solaris, maybe a test for gawk before either
> of these is a good idea.
??? incompatibilities?
> second, isnormal is not defined on solaris, following
isnormal is defined on posix systems under an extension, which is
turned on with the macro _GNU_SOURCE. Obviously won't be there for
solaris, but maybe something analogous is? This is the only sensible
way to distinguish between the least-normalized and least-unnormalized
float constants. Although we might get by with !isnormal ==
fabs(f)<FLT_MIN. Please dig for the equivalent test on your box, and
we can implement.
For the record, normailized floats have a mantissa and exponent, and
typically imply a hidden bit. when the exponent is completely empty,
the mantissa alone implies an effective exponent which extends the
float range down to the unnormalized mon, losing precision gradually
along the way.
Take care,
> is a excerpt from the man page:
>
> man isnan
>
> C Library Functions isnan(3C)
>
> NAME
> isnan, isnand, isnanf, finite, fpclass, unordered - deter-
> mine type of floating-point number
>
> SYNOPSIS
> #include <ieeefp.h>
>
> int isnand(double dsrc);
>
> int isnanf(float fsrc);
>
> int finite(double dsrc);
>
> fpclass_t fpclass(double dsrc);
>
> int unordered(double dsrc1, double dsrc2);
>
> #include <math.h>
>
> int isnan(double dsrc);
>
> DESCRIPTION
> The functionalty of isnan() is identical to that of
> isnand().
>
> isnanf() is implemented as a macro included in the
> <ieeefp.h> header.
>
> fpclass() returns the class the dsrc belongs to. The 10
> possible classes are as follows:
> FP_SNAN signaling NaN
> FP_QNAN quiet NaN
> FP_NINF negative infinity
> FP_PINF positive infinity
> FP_NDENORM negative denormalized non-zero
> FP_PDENORM positive denormalized non-zero
> FP_NZERO negative zero
> FP_PZERO positive zero
> FP_NNORM negative normalized non-zero
> FP_PNORM positive normalized non-zero
>
> None of these routines generate any exception, even for sig-
> naling NaNs.
>
> Is isnormal defined on linux, or is it a posix standard?
> Dan
>
>
--
Camm Maguire address@hidden
==========================================================================
"The earth is but one country, and mankind its citizens." -- Baha'u'llah
- [Gcl-devel] Re: new and improved results.,
Camm Maguire <=