Re: Will tree-ssa be GCC 3.5?

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Jim Wilson <wilson@specifixinc.com> writes:

| On Sat, 2003-11-29 at 15:58, Zack Weinberg wrote:
| > I don't agree.  Major version number bumps should be reserved for
| > changes which are guaranteed to break compatibility for everyone.
| 
| We will never be able to do that, and hence by this criteria, we will
| never be able to change the major version number again.

Yup.

I believe that major compiler internal infrastructure changes as
well as external behaviour changes are good indication for major
version bumps.  That is how I see the move from GCC-2 to GCC-3.  We
got garbage collection, function-at-a-time mode (which was really
really a great step), tree-based inlining, ABI changes...

[...]

| There are a number of issues with tree-ssa that will cause problems for
| lots of people.
| 1) Loss of Ada support, until such time as the Ada front end is
| gimplified.  This will be a major problem for all Ada users.
| 2) Replacing the f77 front end with the f95 front end.  This will be
| noticed by many Fortran users.

I would think that the new driver would have a compatibility mode,
something like -std=f77...

[...]

| If we maintain gcc3 in parallel with gcc4 for a while, then this gives
| us a chance to add in the tree-ssa stuff now even if it isn't perfect
| yet.  People can continue to use gcc3 if necessary until gcc4
| stabilizes.

the same kind of thoughts led me to propose to maintain 3.3.x series
for while, to give users a chance to adapt to 3.4.x. (Of course, C++
users seems to be more affected than other people.)

| If people really don't want to change the version number to 4.0 then I
| can live with that.  I just wanted to make sure it was considered as an
| option.

In my opinion, it would be a mistake not to bump the major version,
given the kind of incompatibilities/problems we can already
anticipate. 

-- Gaby