[PATCH 3/3] Compute predicates for phi node results in ipa-inline-analysis.c

[Jan Hubicka]

> Hi,
> 
> this is a new version of the patch which makes ipa analysis produce
> predicates for PHI node results, at least at the bottom of the
> simplest diamond and semi-diamond CFG subgraphs.  This time I also
> analyze the conditions again rather than extracting information from
> CFG edges, which means I can reason about substantially more PHI
> nodes.
> 
> This patch makes us produce loop bounds hint for the pr48636.f90
> testcase.
> 
> Bootstrapped and tested on x86_64-linux.  OK for trunk?

OK,
thanks!  Do you think you can add testcase?
I plan to reorg the analysis to work in dominator order (now we compute
dominators anyway for lop analysis) that will make this also bit more strong
across non-trivial CFGs. (originally I did not care much since inliner cares
only about simple functions with simple CFG, but with inline hints and other 
stuff we need to be more careful to not throw away useful info.

Honza