== GCC related ==
* PR44557, Thumb-1 ICE: found two small needed corrections in the ARM
backend to fix this. Sent patch upstream.
* LP:641397/PR46888: bitfield insert optimization. Posted patch along
with Andrew Stubbs' CSE patch upstream. The two-patch situation seemed
to stir some discussion :) It seems both patches were deemed okay,
though it would be better if there was some testcase that passed through
unhandled by Andrew's CSE patch, but processed by my combine fix later
in the pass pipeline. Both patches queued at GCC bugzilla page, to be
handled in the next stage1.
* LP:687406/PR46865, -save-temps creating different code. Analyzed
problem, though slow to send fix upstream. Had some discussion on the
list on how the fix should be like.
* PR46667, section type conflicts. Tested and sent mail to gcc-patches.
Jan Hubicka picked it up and pinged for an approval again. Hope this get
resolved soon.
* PR45416, ARM code regression. ARM considerations are mostly okay, main
issue remaining is how to solve the x86 regression. The current expand
code does a full DImode shift just to obtain a single bit, might be
point of improvement to solve this.
* LP:685534, ftbfs with gcc-linaro 4.5 on amd64. Found to be another
erroneous inline asm case. Fixed and updated on LP.
== This week ==
* More upstream and Linaro GCC issues.
* Start dealing with January travel.
* Think more about larger (Linaro) GCC optimization projects.
== Linaro GDB ==
* LP:616000 Handle -fstack-protector prologue code
Understand how frame affect expression validation in GDB. Improve i386
prologue parsing to handle 'and/add' sequence. Revise i386 prologue
parsing for stack protector. Patch is not submitted since still lack of
i386 prologue knowledge, and not very confident on that patch.
Understand prologue-value used in ARM prologue parsing and relationship
of symbol and frame in GDB. Make ARM prologue parsing understands stack
protector code by identify the code sequence. Improve the patch by
supporting ARM mode and ARMv5T, in order to make this patch accepted by
upstreams.
* LP:615972 gdb.base/gcore.exp failure.
The failure is about "corefile restored general registers", which is not
related to NEON register support in corefile. It is caused by
inconsistent register types and names between tdesc and arm. The cause
of this failure is found, but upstreams reviewer doesn't agree on one of
my fix. As he suggested, arm-core.xml is modified to add "type=XXX",
but get some errors when regenerate arm-with-iwmmxt.c. Filed GDB PR 12308.
== GCC ==
* register rename improvements (LP:633243)
Finally, got both middle-end part and ARM part approved. Committed to
upstreams mainline. Some benchmarks in EEMBC shows 0.1%~0.2% code size
reduction.
== This Week ==
* Ping my GDB patches.
* Fix GDB PR 12308, which blocks my fix for LP:615972.
* Backport my approved patches to Linaro GDB if any. Fix other GDB bugs.
* Pass one GCC patch in my queue to review, if I have extra time.
== Vacation ==
Take vacation on Dec 30th and 31st. Travel to ChengDu, and back on 3rd
Jan (It is public holiday in China). Back to work on 4th Jan.
--
Yao (齐尧)
== This week ==
* Away Monday and Tuesday.
* Very little the rest of the week due to other IBM commitments.
I've just finished the main part of that work, so all being well,
it should only need a bit of nannying next week. Most of the week
should be Linaro.
* Started trying to reproduce #641126, but realised that I'd need
to set myself up for general Ubuntu cross package building first.
Started to look at what's involved.
== Next week ==
* Get stuck into #641126.
* More STT_GNU_IFUNC and vectors.
Richard
RAG:
Red:
Amber:
Green:
Milestones:
| Planned | Estimate | Actual |
finish virtio-system | 2010-08-27 | postponed | |
get valgrind into linaro PPA | 2010-09-15 | 2010-09-28 | 2010-09-28 |
complete a qemu-maemo update | 2010-09-24 | 2010-09-22 | 2010-09-22 |
finish testing PCI patches | 2010-10-01 | 2010-10-22 | 2010-10-18 |
Progress:
* merge-correctness-fixes:
** I have sent out an updated ARM fixes pull request, all
of whose components have been Reviewed-by: Nathan Froyd;
I expect this to be merged shortly.
** vqshl(reg) patch posted to list; I have an update which
also addresses vqshl{,u}(imm) which I'll send out as v2
once the first part has been reviewed.
** reviewed and retransmitted Wolfgang's semihosting commandline
patches since he is having trouble sending unmangled mail to
the list
** went through the monster qemu-maemo commit "Lots of ARM TCG changes"
http://meego.gitorious.org/qemu-maemo/qemu/commit/3f17d4e1cb
identifying what fixes it includes
** started looking at a VRSQRTS patch. This uncovered a number
of qemu issues: NaN propagation is wrong, flush-to-zero handling
is only flushing output denormals, not input denormals, and we
don't handle the Neon "standard FPSCR value" but always use the
real FPSCR. I have some preliminary patches for at least some
of this, but since they affect a number of the same bits of
code that are touched by existing not-yet-committed patches I'm
waiting for those to be committed first.
* verify-emulation:
** wrote a README for risu and made it public at
http://git.linaro.org/gitweb?p=people/pmaydell/risu.git;a=summary
* maintain-beagle-models:
** the ubuntu maverick netbook image doesn't boot on qemu because
it uses the OMAP NAND prefetch/DMA, which isn't modelled
https://bugs.launchpad.net/qemu-maemo/+bug/645311
I've started on this and am perhaps halfway through (basic
prefetch code implemented, but DMA and debugging still to go)
* other:
** took part in an OBS mini-sprint where we were walked through
how the OBS buildsystem works and can be used to do test rebuilds
of Meego with new versions of the toolchain.
Meetings: toolchain, pdsw-tools
Plans:
* finish omap NAND prefetch engine work
* make sure ARM changes get committed to qemu...
Absences: (complete to end of 2010)
Fri 17 Dec - Tue 4 Jan inclusive.
2011: Dallas Linaro sprint 9-15 Jan. Holiday 22 Apr - 2 May.
Hi,
* created custom kernel deb packages from the linaro-linux tree in order to
* test the various ftrace tracers and profilers available on ARM
* results at: https://wiki.linaro.org/KenWerner/Sandbox/ftrace
* started to look into crash (kexec, kdump) but wasn't able to generate a
kernel dump yet
Regards
Ken
Dear All
Our team in Samsung collected some performance metrics for the following 3 GCC cross compilers
1.. Gentoo Complier(part of Chrome OS Build Environment)
2.. GCC 4.4.1 (Code Sourcery).
3.. Linaro (gcc-linaro-4.5-2010.11-1)
Flags used to Build Linaro Tool chain
used Michael Hope Script .Just modified "GCCFLAGS = --with-mode=thumb --with-arch=armv7-a --with-float=softfp --with-fpu=neon --with-fpu=vfpv3-d16"
a.. Using the above three tool chains we compiled the kernel of Chrome OS and did Coremark Performance test.(With same optimisation flag mentioned in the attachment)
b.. Test Environment for all the three are the same.
My Questions
1.. Is there any build options that I am missing while I am building the Cross Compiler?
2.. Else is this performance degradation is a know issue and is the tool chain group working on it?.(If so whom to contact?)
Any Pointers from you would be of great help to me.
If you need any further details also do ping me
Regards
Prashanth S
Hi All,
As we discussed on Monday, I think it might be helpful to get a number
of knowledgeable people together on a call to discuss GCC optimization
opportunities.
So, I'd like to get some idea of who would like to attend, and we'll try
to find a slot we can all make. I'm on vacation next week, so I expect
it'll be in two or three week's time.
Before we get there, I'd like to have a list of ideas to discuss. Partly
so that we don't forget anything, and partly so that people can have a
think about them before the day.
I'm really looking for bigger picture stuff, rather than individual poor
code generation bugs.
So here's a few to kick off:
* Costs tuning.
- GCC 4.6 has a new costs model, but are we making full use of it?
- What about optimizing for size?
- Do the optimizers take any notice? [1]
* Instruction set coverage.
- Are there any ARM/Thumb2 instructions that we are not taking
advantage of? [2]
- Do we test that we use the instructions we do have? [3]
* Constant pools
- it might be a very handy space optimization to have small
functions share one constant pool, but the way the passes work one
function at a time makes this hard. (LP:625233)
* NEON
- There's already a lot of work going on here, and I don't want it
to hog all our time, but it might be worth touching on.
What else? I'm not the most experienced person with GCC internals, and
I'm relatively new to the ARM specific parts of those, so somebody else
must be able to come up with something far more exciting!
So, please, get brain-storming!
Andrew
[1] We discovered recently that combine is happy to take two insns and
combine them into a pattern that matches a splitter that then explodes
into three insns (partly due to being no longer able to generate
pseudo-registers).
[2] For example, I just wrote a patch to add addw and subw support (not
yet submitted).
[3] LP:643479 is an example of a case where we don't.
Mostly more working with libffi; swapping some ideas back and forwards with
Marcus Shawcroft and it looks like we have
a good way forward.
Got an armhf chroot going, libffi built.
Got a testcase failing as expected.
Trying to look at other processors ABIs to understand why varargs works for
anyone else.
Cut through one layer of red tape; can now do the next level of comparison
in the string routine work.
Started looking at SPEC; hit problems with network stability on VExpress
(turns out to be bug 673820)
long long weekend; short weeks=2;
Back in on Tuesday.
Dave
Hi,
Those of you use silverbell may be glad to know it's back up.
Be a little careful, if you shovel large amounts of stuff over it's network
the network tends to disappear.
(Not sure if this is hardware or driver)
Dave
Hi,
As mentioned on the standup, I just got an armhf chroot going, thanks to
markos for pointing me at using multistrap
I put the following in a armhfmultistrap.conf and did
multistrap -f armhfmultistrap.conf
Once that's done, chroot in and then do
dpkg --configure -a
it's pretty sparse in there, but it's enough to get going.
Dave
==============================================
[General]
arch=armhf
directory=/discs/more/armhf
cleanup=true
noauth=true
unpack=true
explicitsuite=false
aptsources=unstable unreleased
bootstrap=unstable unreleased
[unstable]
packages=
source=http://ftp.de.debian.org/debian-ports/
keyring=debian-archive-keyring
suite=unstable
omitdebsrc=true
[unreleased]
packages=
source=http://ftp.de.debian.org/debian-ports/
keyring=debian-archive-keyring
suite=unreleased
omitdebsrc=true
