Re: Merging mem-ssa into mainline

["Daniel Berlin" <dberlin at dberlin dot org>]

> Here's a summary of the speedups I obtained with respect to mainline
> @119145.  I am only including timings over the affected modules.  Many
> passes are now faster, but this is mostly due to speedups in the
> operand scanner and SSA updating.  Also, phases that show less than
> 0.5% change are not included:

> cc1-i-files
> -----------
> Phase                           Before  After   % change
> tree PTA                        16.39   15.35     -6.3%
> tree alias analysis             12.33   11.75     -4.7%
> tree SSA rewrite                 6.24    5.13    -17.8%
> tree SSA incremental            15.79   12.09    -23.4%
> tree operand scan               85.90   52.28    -39.1%
> TOTAL                          476.43  437.47     -8.2%

Interesting
Do you actually have any tree-ssa-structalias.c changes in there?

Otherwise, the only reason it would be faster is that it has less
statements to look at.

I'm also about to commit a rewrite of the solving portions of
tree-ssa-structalias that take our time to basically *nothing* on most
cases (we solve all the points-to sets in one pass in cases it used to
take 6, and eliminate solving points-to sets for about 50-70% more
variables through better finding).