From: "Martin Liška" <mliska@suse.cz>
To: Richard Biener <richard.guenther@gmail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>,
Jan Hubicka <hubicka@ucw.cz>, Martin Jambor <mjambor@suse.cz>
Subject: Re: [PATCH][RFC] Make expansion of balanced binary trees of switches on tree level.
Date: Thu, 10 Aug 2017 08:54:00 -0000 [thread overview]
Message-ID: <b128c77b-16d3-d73d-fa6d-f517171ffff4@suse.cz> (raw)
In-Reply-To: <CAFiYyc04cS6qBcReZqx77_=sLw99gfYEPC7YFMsYpOoRRrZxWQ@mail.gmail.com>
On 08/02/2017 01:51 PM, Richard Biener wrote:
> On Wed, Aug 2, 2017 at 1:20 PM, Martin Liška <mliska@suse.cz> wrote:
>> Hello.
>>
>> After some discussions with Honza, I've decided to convert current code in stmt.c that
>> is responsible for switch expansion. More precisely, I would like to convert the code
>> to expand gswitch statements on tree level. Currently the newly created pass is executed
>> at the end of tree optimizations.
>>
>> My plan for future is to inspire in [1] and come up with some more sophisticated switch
>> expansions. For that I've been working on a paper where I'll summarize statistics based
>> on what I've collected in openSUSE distribution with specially instrumented GCC. If I'll be
>> happy I can also fit in to schedule of this year's Cauldron with a talk.
>>
>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>>
>> Thoughts?
>
> First of all thanks.
>
> I think part of switch expansion moved to switch-conversion some time ago
> (emit_case_bit_tests). So maybe the full lowering should be in at least
> the same source file and it should maybe applied earlier for a subset of
> cases (very low number of cases for example).
Hello.
Agree! Eventually we should merge both files into a single one. I would prefer to start
with new generic name of file (gimple-switch-low.c), which will eventually eat content
of tree-switch-conversion.c. Is it acceptable approach?
As Jeff already accepted the patch, I will install it as soon as an agreement in the question
will be done.
Martin
>
> Did you base the code on the RTL expansion code or did you re-write it from
> scratch?
>
> No further comments sofar.
>
> Richard.
>
>> Martin
>>
>> [1] https://www.nextmovesoftware.com/technology/SwitchOptimization.pdf
>>
>> gcc/ChangeLog:
>>
>> 2017-07-31 Martin Liska <mliska@suse.cz>
>>
>> * Makefile.in: Add gimple-switch-low.o.
>> * passes.def: Include pass_lower_switch.
>> * stmt.c (dump_case_nodes): Remove and move to
>> gimple-switch-low.c.
>> (case_values_threshold): Likewise.
>> (expand_switch_as_decision_tree_p): Likewise.
>> (emit_case_decision_tree): Likewise.
>> (expand_case): Likewise.
>> (balance_case_nodes): Likewise.
>> (node_has_low_bound): Likewise.
>> (node_has_high_bound): Likewise.
>> (node_is_bounded): Likewise.
>> (emit_case_nodes): Likewise.
>> * timevar.def: Add TV_TREE_SWITCH_LOWERING.
>> * tree-pass.h: Add make_pass_lower_switch.
>> * gimple-switch-low.c: New file.
>>
>> gcc/testsuite/ChangeLog:
>>
>> 2017-07-31 Martin Liska <mliska@suse.cz>
>>
>> * gcc.dg/tree-prof/update-loopch.c: Scan patterns in
>> switchlower.
>> * gcc.dg/tree-ssa/vrp104.c: Likewise.
>> ---
>> gcc/Makefile.in | 1 +
>> gcc/gimple-switch-low.c | 1226 ++++++++++++++++++++++++
>> gcc/passes.def | 1 +
>> gcc/stmt.c | 861 -----------------
>> gcc/testsuite/gcc.dg/tree-prof/update-loopch.c | 10 +-
>> gcc/testsuite/gcc.dg/tree-ssa/vrp104.c | 2 +-
>> gcc/timevar.def | 1 +
>> gcc/tree-pass.h | 1 +
>> 8 files changed, 1236 insertions(+), 867 deletions(-)
>> create mode 100644 gcc/gimple-switch-low.c
>>
>>
next prev parent reply other threads:[~2017-08-10 7:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-02 11:20 Martin Liška
2017-08-02 11:51 ` Richard Biener
2017-08-02 12:49 ` Martin Liška
2017-08-03 9:02 ` Jan Hubicka
2017-08-03 16:11 ` Jeff Law
2017-08-03 12:22 ` Steven Bosscher
2017-08-10 8:54 ` Martin Liška [this message]
2017-08-14 9:26 ` Richard Biener
2017-08-15 12:50 ` Martin Liška
2017-08-18 10:29 ` Richard Biener
2017-08-18 11:05 ` Martin Liška
2017-08-24 17:21 ` Martin Liška
2017-08-29 12:58 ` Richard Biener
2017-08-29 15:11 ` Martin Liška
2017-08-30 9:18 ` Rainer Orth
2017-08-30 12:29 ` Martin Liška
2018-03-25 10:12 ` [testsuite, committed] Make scan pattern more precise in vrp104.c Tom de Vries
2017-08-02 13:38 ` [PATCH][RFC] Make expansion of balanced binary trees of switches on tree level David Malcolm
2017-08-03 12:52 ` Steven Bosscher
2017-08-03 12:56 ` Richard Biener
2017-08-03 13:20 ` Jan Hubicka
2017-08-03 13:28 ` Steven Bosscher
2017-08-04 11:19 ` Martin Liška
2017-08-04 11:19 ` Martin Liška
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b128c77b-16d3-d73d-fa6d-f517171ffff4@suse.cz \
--to=mliska@suse.cz \
--cc=gcc-patches@gcc.gnu.org \
--cc=hubicka@ucw.cz \
--cc=mjambor@suse.cz \
--cc=richard.guenther@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).