This is the mail archive of the newlib@sourceware.org mailing list for the newlib project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: isnanf cleanup

From: Ken Werner <ken at linux dot vnet dot ibm dot com>
To: newlib at sourceware dot org, Jeff Johnston <jjohnstn at redhat dot com>, "Howland Craig D (Craig)" <howland at lgsinnovations dot com>
Date: Tue, 7 Jul 2009 16:29:23 +0200
Subject: Re: isnanf cleanup
References: <570409110.664671246641599668.JavaMail.root@zmail02.collab.prod.int.phx2.redhat.com>

On Friday 03 July 2009 07:19:59 pm Jeff Johnston wrote:
> Hi Craig,
>
> Sorry for the delay.
>
> Patch has a problem.  It will break spu math library.  The spu will define
> isnan and isinf to not support float values which will override the
> definitions in math.h.  Don't know why SPU has those macros in
> machine/ieeefp.h but they should be rewritten to match the ones in math.h
> or removed entirely.
>
> -- Jeff J.

Hi,
Why does this patch break the SPU math library?
The reason that the isinf and isnan macros are overwritten by the 
machine/ieeefp.h is that these are evaluated at compile time and thus faster 
than the math.h variant which calls fpclassify. They could be rewritten to use 
fpclassify instead of __isinfd/__isnand but we don't have an optimized 
__fpclassifyd routine like our vectorized isnan code.

-ken

Follow-Ups:
- Re: isnanf cleanup
  - From: Jeff Johnston

References:
- Re: isnanf cleanup
  - From: Jeff Johnston

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]