Re: Mainline is now regression and documentation fixes only

[Richard Guenther <rguenther at suse dot de>]

On Wed, 23 Jan 2008, Peter Bergner wrote:

> On Wed, 2008-01-23 at 12:06 +0100, Richard Guenther wrote:
> > As we now reached the goal of less than 100 open serious regressions
> > against GCC 4.3, we are as of now in regression and documentation fixes
> > only mode.  This means that for patches going on the trunk the same
> > rules as for release branches apply.
> 
> Is the following patch to fix PR 34814 which was posted shortly before
> your announcement ok?  It has passed bootstrap and regtesting with
> no errors and fixes test case gcc.target/powerpc/ppc32-abi-dfp-1.c.
> 
>   http://gcc.gnu.org/ml/gcc-patches/2008-01/msg01060.html
> 
> It fixes an ABI issue with powerpc-linux and powerpc64-linux regarding
> SDmode parameters and return values.  The patch will allow us to mix
> and match GCC compiled obj files with XL compiled obj files which is
> already following the ABI.
> 
> I restricted the changes to the rs6000 port except for a couple of
> additional target hooks which are nop's for non ppc targets and a simple
> rename of one function to eliminate a symbol collision between
> function.c:instantiate_decl and cp/pt.c:instantiate_decl().

The backend changes should be acked by a backend maintainer, the 
middle-end changes look non-intrusive enough that they are obvious if
the rest is considered ok.  I would say an ABI fix like this would
qualify as a P1 bug - how is its regression state?  DFP support was
added for 4.2, right?  Does this make 4.3 incompatible with 4.2?
If so it should be documented in the changes document at least,
possibly configurable with a target switch?

So in the end target maintainers should weight the risk of late
(but important in their view) fixes like this.

Thanks,
Richard.