Re: [PATCH][RFC] Sanity checking for -freorder-blocks-and-partition failures

[Christophe Lyon <christophe dot lyon at st dot com>]

On 30.10.2012 17:59, Teresa Johnson wrote:
> On Tue, Oct 30, 2012 at 9:26 AM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> > Hello,
> >
> > Hot/cold partitioning is apparently a hot topic all of a sudden, which
> > is a good thing of course, because it's in need of some TLC.
> >
> > The attached patch adds another check the RTL cfg checking
> > (verify_flow_info) for the partitioning: A hot block can never be
> > dominated by a cold block (because the dominated block must also be
> > cold). This trips in PR55121.
> >
> > I haven't tested this with any profiling tests, but it's bound to
> > break things. From my POV, whatever gets broken by this patch was
> > already broken to begin with :-)   If you're in CC, it's because I
> > hope you can help test this patch.
> I will try testing your patch on top of mine with our fdo benchmarks.
> For the others on the cc list, you may need to include my patch as
> well for testing. Without it, -freorder-blocks-and-partition was DOA
> for me. For my patch, see
> http://gcc.gnu.org/ml/gcc-patches/2012-10/msg02692.html
>
> Teresa
I have tried Steven's patch an indeed it reported numerous errors while compiling spec2k.

I tried Teresa's patch too, but it changed nothing in my tests. The patches already posted by Matt are still necessary and Teresa's patch does not improve my tests.

I am out of office at the moment, so it's a little bit inconvenient to investigate deeper the reasons for all the errors reported by Steven's patch. Anyway it looks like it's really needed :)
I also noticed that some compilations failed with an ICE in calc_dfs_tree at dominance.c:395.


Christophe.