Re: [boost] Boost.config limits_test testcase and qnan checks.

Subject: Re: [boost] Boost.config limits_test testcase and qnan checks.
From: John Maddock (boost.regex_at_[hidden])
Date: 2012-07-13 12:14:52

> First an introduction; my name is Matt Markland and I support the Cray 
> Compiling Environment (CCE) C/C++ compiler for Cray, Inc.  We (Cray) are 
> in the process of improving our Boost support and currently have an intern 
> doing some work for us on this path.  While working on Boost.config, he 
> has run into a testcase failure with the limits_test function 
> test_float_limits().  With default options, CCE fails the qnan tests due 
> to the fact that we do not conform to the  IEEE specification.  CCE is a 
> little different here in that by default it runs at a higher optimization 
> level then other compilers.  Gcc will fail this portion of the test if you 
> compile with optimization on and -ffast-math.
>
> My question is whether it is valid to test the qnan behavior when a 
> platform does not claim compliance?  It seems to me that these checks 
> should be wrapped in an is_iec559 check.

I think that's a valid point to make - I've disabled the test for inequality 
between NaN's unless is_iec559 is true.

Great to see you're working on compiling Boost too!

John.