[RFC][PATCH v2] MIPS: IEEE 754-2008 NaN encoding support

[Joseph S. Myers]

On Tue, 10 Sep 2013, Maciej W. Rozycki wrote:

>  I infer you'd prefer to have this change committed even though the 
> required kernel part isn't there yet, right?  I have therefore set the 
> minimum version required artificially to 10.0.0 so that this code is not 
> accidentally activated on a kernel that doesn't support the 2008-NaN 
> feature and put a FIXME note next to it.  Please let me know if this is 
> what you had in mind.

Yes, using 10.0.0 here seems reasonable.

More generally, that would also seem appropriate if a new architecture 
port were submitted and approved before the kernel port is upstream.  
Rather than require a strict ordering of components going upstream 
(binutils, GCC, Linux kernel, glibc; GDB anywhere after binutils), lots of 
unnecessary delays can be avoided by each component reviewing 
independently, possibly in parallel, with the understanding that 
incompatible changes may still be possible if a component you depend on 
that's not yet upstream has such changes.  (Because of circular 
dependencies, you can't fully avoid that anyway; GCC for various 
architectures includes information about signal frames produced by the 
Linux kernel, for example.)

At the point when the kernel support goes upstream, the version in glibc 
can then be changed to reflect the correct upstream kernel version (in the 
case of new architecture ports, it's possible more __ASSUME_* macros may 
also be defined, or conditionals removed, based on what was in the kernel 
version that went upstream).

-- 
Joseph S. Myers
joseph@codesourcery.com