This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC 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: [RFC][4.4] PR rtl-optimization/3507 appalling optimization with sub/cmp


On Wed, 28 Nov 2007, Joseph S. Myers wrote:

> On Wed, 28 Nov 2007, Rask Ingemann Lambertsen wrote:
> 
> >    I'll be submitting approximately the patch below when trunk reopens for
> > stage1. At the moment I'm looking for comments. For example, I'm expecting
> > someone to say a few words about floating point issues, but feel free to
> 
> I'm not clear what you want said about floating-point issues (something 
> for a comment in the code about why it must be integer-only?), but for 
> example inf == inf but inf - inf == NaN.

Correction: inf == inf is true, while inf - inf has the value NaN (not 0) 
but "inf - inf == NaN" is false because NaN != NaN.

-- 
Joseph S. Myers
joseph@codesourcery.com


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