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Re: Loop optimizer issues
Hello,
> > - Zdenek's value range profiling code. This one is half way in the
> > mainline. I really hoped to see this merged in 3.4 but I am not
> > quite sure this will happen.
> > This is major problem in merging mainline as Nathanel's work on gcov
> > did cause gread amount of conflicts..
> [...]
> > - Josef's variable tracking and Daniel's location lists. I believe
> > there is useable version sent for review for some time but it has
> > problem with losing track when value is copied to temporary location
> > that is later killed. This is relatively minnor problem in the
> > algorithm as the interfaces are major problem right now here.
> >
> > I believe we have to solve this in order to get nice debugging out of
> > de-SSA once we drop limitations on de-SSAizing. It is also solving
> > problems with -frename-registers as well as with webizer rendering
> > variable values random in debugger.
>
> I'm not sure what to do about these. Clearly the location list
> support is highly desirable, but I thought you said when I pinged
> you last is that it didn't work reliably.
there are some problems with it, I think Josef is working on them now.
Also some bug in it caused libstdc++ not to compile, so I disabled it
for now, but it should be easy to fix.
Considering value range profiling code, I think all places where it
could conflict with Nathan's changes are isolated in instrumentation
(already merged in) and profile reading (waiting for review), so this
should not be a problem. Of course it introduces a new optimizations
and does not fix any regressions, so it does not quite fit stage 2, but
given that it is already partially merged in, I would prefer finishing
it now.
Zdenek