From: Richard Biener <rguenther@suse.de>
To: Sebastian Pop <sebpop@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH][0/n] Merge from match-and-simplify
Date: Fri, 17 Oct 2014 08:00:00 -0000 [thread overview]
Message-ID: <alpine.LSU.2.11.1410170951450.9891@zhemvz.fhfr.qr> (raw)
In-Reply-To: <20141016203852.GB29134@f1.c.bardezibar.internal>
On Thu, 16 Oct 2014, Sebastian Pop wrote:
> Richard Biener wrote:
> >
> > I have posted 5 patches as part of a larger series to merge
> > (parts) from the match-and-simplify branch. While I think
> > there was overall consensus that the idea behind the project
> > is sound there are technical questions left for how the
> > thing should look in the end. I've raised them in 3/n
> > which is the only patch of the series that contains any
> > patterns sofar.
> >
> > To re-iterate here (as I expect most people will only look
> > at [0/n] patches ;)), the question is whether we are fine
> > with making fold-const (thus fold_{unary,binary,ternary})
> > not handle some cases it handles currently.
>
> I have tested on aarch64 all the code in the match-and-simplify against trunk as
> of the last merge at r216315:
>
> 2014-10-16 Richard Biener <rguenther@suse.de>
>
> Merge from trunk r216235 through r216315.
>
> Overall, I see a lot of perf regressions (about 2/3 of the tests) than
> improvements (1/3 of the tests). I will try to reduce tests.
Note that the branch goes much further in exercising the machinery
than I want to merge at this point (that applies mostly to all
passes using the SSA propagator such as CCP and VRP and passes
exercising value-numbering - FRE and PRE).
It may also simply show the effect of now folding all statements
from tree-ssa-forwprop.c. I have yet to investigate the testsuite
fallout of [1/n] to [5/n] - testresults have been very noisy lately
due to the C11 change and now ICF.
> For instance, saxpy regresses at -O3 on aarch64:
>
> void saxpy(double* x, double* y, double* z) {
> int i=0;
> for (i = 0 ; i < ARRAY_SIZE; i++) {
> z[i] = x[i] + scalar*y[i];
> }
> }
>
> $ diff -u base.s mas.s
> --- base.s 2014-10-16 15:30:15.351430000 -0500
> +++ mas.s 2014-10-16 15:30:16.183035000 -0500
> @@ -2,12 +2,14 @@
> add x1, x2, 800
> ldr q0, [x0, x2]
> add x3, x2, 1600
> + cmp x0, 784
> ldr q1, [x0, x1]
> + add x1, x0, 16
> fmla v0.2d, v1.2d, v2.2d
> str q0, [x0, x3]
> - add x0, x0, 16
> - cmp x0, 800
> + mov x0, x1
> bne .L140
> .LBE179:
> - subs w4, w4, #1
> + cmp w4, 1
> + sub w4, w4, #1
> bne .L139
I don't understand AARCH64 assembly very well but the above looks like
RTL issues and/or IVOPTs issues?
Thanks for doing performance measurements.
Richard.
next prev parent reply other threads:[~2014-10-17 7:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-15 13:20 Richard Biener
2014-10-15 16:30 ` Kyrill Tkachov
2014-10-17 7:39 ` Ramana Radhakrishnan
2014-10-17 8:24 ` Richard Biener
2014-10-17 11:58 ` Richard Biener
2014-10-15 17:13 ` Jakub Jelinek
2014-10-16 20:43 ` Sebastian Pop
2014-10-16 20:50 ` Andrew Pinski
2014-10-17 7:29 ` Ramana Radhakrishnan
2014-10-17 8:00 ` Richard Biener [this message]
2014-10-17 16:44 ` Sebastian Pop
2014-10-17 17:37 ` Richard Biener
2014-10-17 18:32 ` Sebastian Pop
2014-10-20 11:47 ` Richard Biener
2014-10-22 21:06 ` Jeff Law
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=alpine.LSU.2.11.1410170951450.9891@zhemvz.fhfr.qr \
--to=rguenther@suse.de \
--cc=gcc-patches@gcc.gnu.org \
--cc=sebpop@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).