Re: [PATCH] Ranger : Do not process abnormal ssa-names.

[Andrew MacLeod <amacleod@redhat.com>]

On 10/16/21 5:27 AM, Andrew Pinski wrote:
> On Fri, Oct 15, 2021 at 6:53 AM Andrew MacLeod via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>> I've been looking at the pathological time issue ranger has with the
>> testcase from, uuuuuh..  PR 97623 I think.  I've lost the details, but
>> kept the file since it was showing unpleasant behaviour.
>>
>> Most of the time is spent in callbacks from substitute_and_fold to
>> value_on_edge()  dealing with PHI results and arguments.  Turns out, its
>> virtually all wasted time dealing with SSA_NAMES with the
>> OCCURS_IN_ABNORMAL_PHI flag set..
>>
>> This patch tells ranger not to consider any SSA_NAMEs which occur in
>> abnormal PHIs.  This reduces the memory footprint of all the caches, and
>> also has a ripple effect with the new threader code which uses the GORI
>> exports and imports tables, making it faster as well as no ssa-name with
>> the abnormal flag set will be entered into the tables.
>>
>> That alone was not quite enough, as all the sheer volume of call backs
>> still took time,  so I added checks in the value_of_* class of routines
>> used by substitute_and_fold to indicate there is no constant value
>> available for any SSA_NAME with that flag set.
>>
>> On my x86_64 box, before this change, that test case looked like:
>>
>> tree VRP                           :   7.76 (  4%)   0.23 ( 5%)   8.02
>> (  4%)   537k (  0%)
>> tree VRP threader                  :   7.20 (  4%)   0.08 (  2%) 7.28 (
>> 4%)   392k (  0%)
>> tree Early VRP                     :  39.22 ( 22%)   0.07 (  2%) 39.44 (
>> 22%)  1142k (  0%)
>>
>> And with this patch , the results are:
>>
>>    tree VRP                           :   7.57 (  6%)   0.26 ( 5%)   7.85
>> (  6%)   537k (  0%)
>>    tree VRP threader                  :   0.62 (  0%)   0.02 ( 0%)   0.65
>> (  0%)   392k (  0%)
>>    tree Early VRP                     :   4.00 (  3%)   0.01 ( 0%)   4.03
>> (  3%)  1142k (  0%)
>>
>> Which is a significant improvement, both for EVRP and the threader..
>>
>> The patch adjusts the ranger folder, as well as the hybrid folder.
>>
>> bootstrapped on x86_64-pc-linux-gnu with no regressions and no missed
>> cases that I have been able to find.
> Did you test it with go enabled?
> Because others and myself are now running into a bootstrap failure
> most likely due to this patch.
> The number of SSA_NAME_OCCURS_IN_ABNORMAL_PHI in go is increased due
> to -fnon-call-exceptions being true there.

I would have sworn upside down I did, but looking at my build script, 
somewhere along the way GO got turned off, so although I was building 
ada, GO was not being included.. sorry.

I'll get this resolved this afternoon.

Andrew