== This week ==
* Spent about half of the week on auto increment/decrement. There are two
execution failures left.
* Looked at assembly comparisons between the old pass and various forms
of the new pass. The results look reasonable.
* Ran DENbench and my libav microbenchmarks to measure the difference
in performance. Saw that some tests were repeatably worse.
* Looked into those tests and realised that they were being hit by the
lack of an address writeback model in the scheduler (a known limitation).
Dependent stores were being scheduled in a block at the end of the loop
because we said that the dependencies had 0 latency.
* Spent most of the rest of the week on fixing that limitation. One of the
difficulties is that define_bypass currently requires a complete list
of instruction reservations. This is difficult for things like writeback
because the result could in principle be used by many different instructions.
Decided to generalise define_bypass so that it can handle filename-style
globs.
* Wrote a patch to model writeback in NEON.
* Wrote a patch to model writeback in core instructions. However,
while doing this, I noticed that the behaviour I'm seeing on our
Cortex-A8 doesn't match what I'd expected from GCC's A8 scheduler
description (or the documentation). Talked with Ramana about it.
Distilled a benchmark.
* These scheduler changes didn't improve the DENbench and libav
scores much by themselves, but the combination of the scheduler
and auto inc/dec changes did produce noticeable improvements
in some libav benchmarks and rather smaller improvements in
some DENbench ones.
== Next week ==
* Finish scheduler work, in light of observed behaviour.
* More testing prior to submission.
I'm away the week of 13th June.
Richard
Hi,
- bug fixes: PRs 49222, 49199, 49239, 49093
- widening multiplication: submitted a patch to support widen-mul for
unsigned types and constants in the vectorizer's pattern recognizer.
Now considering to move optimize_widening_mul pass before loop
optimizations and improve it to support unsigned and constants
Next week: holiday on Tuesday (half day) and Wednesday.
Ira
2011/5/29 Fathi Boudra <fathi.boudra(a)linaro.org>:
> Hi,
>
> The Linaro Team is pleased to announce the release of Linaro 11.05.
>
> 11.05 is the second public release that brings together the huge amount of
> engineering effort that has occurred within Linaro over the past 6 months.
>
> This is the first release delivering Android, Ubuntu and the Working Group
> components nicely bundled into one release. We will continue to pick up more
> Working Group and Landing Team outputs in the upcoming monthly releases.
>
> We encourage everybody to use the 11.05 release. The download links for all
> images and components are available on our release page:
>
> http://wiki.linaro.org/Cycles/1105/Final
>
> Highlights of this release:
>
> * Linaro GCC 4.5, GCC 4.6 and GDB 7.2 2011.05, recently released components
i have been wondering why always two versions are released at the same
time. what kind of users are expected to use 4.5, and what kind of
users are expected to use 4.6?
my another question is whether we have a policy to maintain old
realease. for example, in case1105 has some bugs, is it possible
linato toolchain team fix those bugs in the old version later. many
users are using old version with bugs, if they move to new version
directly, new feature maybe import new bugs. so people maybe want to
use old version with bug fixes, but without new features.
> created by the Toolchain Working Group.
> * Linaro Kernel 2011.05-2.6.38, the first source tarball release of Linux
> Linaro done by the Kernel Working Group.
> * Linaro Evaluation Builds (LEBs) for Android and Ubuntu on PandaBoard with
> 3D graphics acceleration.
> * Android cross toolchain based on latest gcc-linaro and gdb-linaro
> * Host development tools (cross compiler, image builders) readily integrated
> for the Ubuntu distribution users (Lucid, Maverick and Natty support).
> * And many more...
>
> Using the Android-based images
> ==============================
>
> The Android-based images come in three parts: system, userdata and boot.
> These need to be combined to form a complete Android install. For an
> explanation of how to do this please see:
>
> http://wiki.linaro.org/Platform/Android/ImageInstallation
>
> If you are interested in getting the source and building these images
> yourself please see the following pages:
>
> http://wiki.linaro.org/Platform/Android/GetSource
> http://wiki.linaro.org/Platform/Android/BuildSource
>
> Using the Ubuntu-based images
> =============================
>
> The Ubuntu-based images consist of two parts. The first part is a hardware
> pack, which can be found under the hwpacks directory and contains hardware
> specific packages (such as the kernel and bootloader). The second part is
> the rootfs, which is combined with the hardware pack to create a complete
> image. For more information on how to create an image please see:
>
> http://wiki.linaro.org/Platform/DevPlatform/Ubuntu/ImageInstallation
>
> Getting involved
> ================
>
> More information on Linaro can be found on our websites:
>
> * Homepage: http://www.linaro.org
> * Wiki: http://wiki.linaro.org
>
> Also subscribe to the important Linaro mailing lists and join our IRC
> channels to stay on top of Linaro developments:
>
> * Announcements:
> http://lists.linaro.org/mailman/listinfo/linaro-announce
> * Development:
> http://lists.linaro.org/mailman/listinfo/linaro-dev
> * IRC:
> #linaro on irc.linaro.org or irc.freenode.net
> #linaro-android irc.linaro.org or irc.freenode.net
>
> Known issues with this release
> ==============================
>
> For any errata issues, please see:
>
> http://wiki.linaro.org/Cycles/1105/Final#Known_Issues
>
> Bug reports for this release should be filed in Launchpad against the
> individual packages that are affected. If a suitable package cannot be
> identified, feel free to assign them to:
>
> http://www.launchpad.net/linaro
>
> Cheers,
>
> Fathi Boudra
> --
> Linaro Release Manager | Platform Project Manager
>
> _______________________________________________
> linaro-announce mailing list
> linaro-announce(a)lists.linaro.org
> http://lists.linaro.org/mailman/listinfo/linaro-announce
>
Hi,
* finished the measuring of the overhead of the ARM specific unwind tables
https://wiki.linaro.org/KenWerner/Sandbox/libunwind#overhead_of_the_ARM_spe…
* started to get an environment up and running in order to build the
linaro-android sources
* encountered some build issues (I'm in the process to sort out some
issue with pfalcon of the android team)
* finshed 11.11 cycle planning
* I'll be out of office for the rest of the week (public holiday +
vacation)
Regards
Ken
Progress:
* Some trouble building the SPEC2k tools in the new multiarch world in
natty. Perl refuses to link libm and a number of other things
also end up failing . Appears to be a real pain with the new multiarch
world and SPEC2k's curious build system for its' tools . Will fall back
to an older chroot and get the tools built natively.
* Tried breaking down the T2 performance blueprint - initial breakdown
now available.
* Looked at the binutils vmov.i64 issue again. Looks like natty-updates
will now pick this up.
* Some patch review and bugzilla maintenance.
Plans:
* Get SPEC tools building.
* Look more at the T2 performance blueprint
* Spend some time on the VFP moves and look at ivopts for a bit.
* Merge review duty.
Meetings:
* 1-1s
* Linaro calls.
== Last week ==
* Investigated the CoreMark numbers posted by Michael Hope, mainly the
oddities of a significant Linaro 4.6 regression versus FSF 4.6. Later
verified to be a false alarm.
* Pushed a merge of some of my upstream CoreMark patches to Linaro 4.6.
* Did archeology for PR42017. Traced some history of the ARM prologue
from 2000 to 2007 (DF branch), posted upstream. Hope this clarification
gets my patch an approval soon.
* Tried the above PR42017 patch (which is supposed to release the use of
LR as a general register in leaf functions) on CoreMark, using Linaro
4.6, and was surprised to find that despite many reductions in spill
code and epilogue (now more often directly return by ldmfd), the
generated code still regresses in performance (!).
* Continuing above, suspecting something from experience (cough) added
-falign-functions=8 to the CoreMark compile options. Finally produced a
small improvement, while causing a regression for the
without-PR42017-patch case (victory?).
* Worked on PR48808, PR48792 over the weekend, which are cases where
paradoxical subregs caused ICE in reload. Posted an ARM backend patch
upstream, though now mostly taken over by Richard Sandiford :)
== This week ==
* Some other PRs, ideas, still work in progress.
* Started using the porter boards, will try to get LP:689887 over with
this week.
* Set-up SPEC2006 profile runs on PowerPC with trunk.
* Looked at SPEC2006's 462.libquantum.
* PR745743 - compared different versions mentioned in the PR.
* Wrote a patch to fix another issue related to how SMS handles debug_insn.
== String routines ==
* Finally finished the ltrace analysis of the whole of SPEC 2k6 and
have written it up - I'll proof read it next week and then send it out
to the benchmark list.
* Ran memset and memcpy benchmarks of larger than cache sizes on A9
* memcpy on larger than cache sizes (or probably mainly cache miss
data) does come back to Neon winning over ARM; my suspicion is that
with cache hits we run out of bandwidth on Neon, but that doesn't
happen in the cache miss case; why it's faster in that case I'm not
sure yet.
* memset is still not faster for Neon even on large sizes where
the destination isn't in the cache.
== Other ==
* Started looking at 64 bit atomics
* Looking at the pot of QEmu work with Peter.
Dave
