Re: [tree-ssa] some manual store sinking for tree-dfa

[Jan Hubicka <hubicka at ucw dot cz>]

> On Mon, 2003-12-08 at 19:08, Steven Bosscher wrote:
> > Hi,
> > 
> > Honza noted that, surprisingly, tree-dfa.c:add_vdef is a bottleneck.
> > This patch help a bit, but not enough.  Walking over two potentially
> > big varrays, bah...
> > 
> > BTW Without this patch we could sink the store to source, but I've
> > verified that we don't do that.  Is store sinking implemented?
> > 
> > Bootstrapped & tested on i686-pc-linux-gnu.  OK, or is this going
> > away when Andrew is done with his new voperands data structs?
> > 
> 
> > 
> > 	* tree-dfa.c (add_vdef): Only store `source' if we've found it.
> > 
> 
> 
> Hmm.  Its not completely going away, but it is being reworked
> significantly. I will rework it a bit more carefully based on those
> observations, and at the very least, incorporate your changes.  I'll see
> if I can speed it up even more than that tho.

To be more specific, I've measured 3.7% of time spent there in
unoptimized enable checking compiler.  Most of the time is accounted to
verify_ssa that makes verify_ssa looks worse than it really is (as the
time would be spent later in subsequent pass using stmt_operands).
Still good motivation to get verify_ssa faster (it is 5% on Geralds
testcase currently)

In the case the loop looking for duplicates is major problem, we can
simply reserve flag in tree node for this that is set each time we
insert new vop and reset of all vops once we are done.

Honza
> 
> THanks
> 
> Andrew