[fixed-point] Fixed-point branch merge plan

[fixed-point] Fixed-point branch merge plan

[Fu, Chao-Ying]

Hi,

  As Mark requested, we propose a merge plan for the fixed-point branch
as follows.

1. Merge in machine modes to support signed and unsigned
fract and accum modes.  Handle scalar and vector modes.

2. Merge in fixed-value.h and fixed-value.c to handle fixed-point values.
 
3. Merge in TREE structures for fixed-point types and constants.

4. Merge in C front-end changes to parse _Sat, _Fract and _Accum.

5. Merge in RTL structures for fixed-point constants and operators.

6. Merge in libcpp to parse fixed-point constants.

7. Merge in changes to support "case" of FIXED_POINT_TYPE, FIXED_CST,
and CONST_FIXED in .c and .h files.

8. Merge in the MIPS backend that supports fixed-point instructions.

9. Merge in configure/build system changes for the runtime library.

10. Merge in testsuite (from gcc.dg/fixed-point) that only run
when the compiler is configured to enable fixed-point.

  This plan is similar to the DFP merge plan from this link.
http://gcc.gnu.org/ml/gcc/2005-11/msg01128.html
Our changes will be active for the mips target and all other targets
should not be affected.  For each step, we will wait for some days
to fix any breakage.  Comments are welcome!

  Thanks a lot!

Regards,
Chao-ying

Re: [fixed-point] Fixed-point branch merge plan

[Mark Mitchell]

Fu, Chao-Ying wrote:

>   As Mark requested, we propose a merge plan for the fixed-point branch
> as follows.

I think this is a good plan.  Since there have been no negative
comments, let's go with this approach.

I've looked at the big patch you posted, and I think it looks very good
overall.  You will still need approval for the patches at each stage of
the merge, though.  I am hoping the appropriate maintainers will step up
to review each piece.  However, if the process gets stuck, let me know,
and I will step in to help.

Please wait until the PTR_PLUS branch is merged before beginning your
merge.  However, you may of course start preparing your patches, and
posting them for review, if you like.  I just want you to let Andrew go
first in terms of actually checking in the changes.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713