== This week ==
* Away Monday, and a fair bit of time on non-Linaro duties.
* Looked at Dave's gromacs bug (693502). Turned out to be a reload
inheritance problem. Tested a patch. Spent some time coming up with
a brute-force testcase that I can submit with the patch.
* Found a bug in the x86 and x86_64 ifunc support that would affect
ARM too if we weren't careful. Came up with an example testcase
and filed the bug upstream:
http://sourceware.org/bugzilla/show_bug.cgi?id=12366
It has been fixed by H.J. Lu. I'm wondering about taking a
slightly different approach for ARM.
* More ifunc work.
* Tried again to reproduce the chrome failure, making sure to use
DEB_BUILD_HARDENING=1. (I hadn't realised first time round that,
in reaction to this bug, debian/rules specifically excluded armel
from the automatic DEB_BUILD_HARDENING=1 setting.) The build
takes a couple of days on my BeagleBoard.
Heh, and just as I wrote that, the build failed with the reported
link error. Neat.
== Next week ==
* Finish testing the patch for 693502 and submit it upstream.
Backport the patch to our tree once accepted.
* Look at the chromium problem.
* More ifunc.
Richard
RAG:
Red:
Amber:
Green: qemu git pull request accepted, patches seem to be flowing
into qemu upstream more freely now
Milestones:
| Planned | Estimate | Actual |
finish virtio-system | 2010-08-27 | postponed | |
finish testing PCI patches | 2010-10-01 | 2010-10-22 | 2010-10-18 |
successful ARM qemu pull req | 2010-12-16 | 2010-12-16 | 2010-12-16 |
finish qemu-cont-integration | 2010-01-25 | 2010-01-25 | |
Bonus extended holiday edition:
This report includes a number of things that happened over
the Christmas holidays as well as this week (which is
a short one, only 3 days).
Progress:
* merge-correctness-fixes:
** my git pull request for various ARM qemu patches was merged!
** a number of other patches were merged to qemu master:
+ implement correct NaN propagation rules
+ rename softfloat float*_is_nan() functions
+ fix UMAAL (Aurelien's patch, reviewed by me)
+ VQSHL (reg) patchset
** diagnosed the segfault in
https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/604872
and wrote a patchset which fixes it (and related problems):
http://patchwork.ozlabs.org/patch/77887/ (n/7)
** wrote and posted a patchset which implements save/restore
for the versatile platform (so I didn't have to wait 10
minutes for the test case to reach the segfault)
http://patchwork.ozlabs.org/patch/76529/
** finished and posted a patchset implementing flushing of
denormals to zero on input:
http://patchwork.ozlabs.org/patch/77798/ (n/3), now committed
** reviewed/tested Aurelien's SMMLA/SMMLS patch (now committed)
** wrote and posted patches which implement the FS_IOC_FIEMAP
ioctl (http://patchwork.ozlabs.org/patch/77725/) and
the file_sync_range{,2} syscalls
(http://patchwork.ozlabs.org/patch/77723/) -- these are used
by apt, and so linaro-media-create was generating a lot of
warnings from qemu about their lack of implementation
** posted patch to clean up NaN handling in linux-user NWFPE
emulation (follow-on from earlier NaN cleanups):
http://patchwork.ozlabs.org/patch/77795/
* maintain-beagle-models:
** implemented minimal ARM cp14 debug registers
and a random register in the TWL4030 emulation (both needed
to get recent Linaro kernels to boot on the beagle model)
Submitted merge request upstream:
http://meego.gitorious.org/qemu-maemo/qemu/merge_requests/3
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Meetings: toolchain standup, pdsw doughnuts
Absences:
2011: Dallas Linaro sprint 9-15 Jan. Holiday 21 Jan, 22 Apr - 2 May.
Hi,
* implemented reduction support in SLP, I'll check if it helps
DenBench next week
* helping Sebastian Pop with if-conversion for vectorization
improvements (BTW, Sebastian's goal is to vectorize kernels from
ffmpeg)
* fixed GCC PR47139
Ira
Hi All,
Thanks for attending the call. I think we had some interesting discussions.
I've posted the minutes from the call on the same page as before:
https://wiki.linaro.org/AndrewStubbs/Sandbox/GCCoptimizations
I'll try to get the audio posted somewhere for anybody that's interested.
Andrew
You may have noticed that I have created a new BZR/Launchpad branch for
Linaro GCC 4.6:
lp:gcc-linaro/4.6
https://code.launchpad.net/~linaro-toolchain-dev/gcc-linaro/4.6
Up until now, this has not been buildable due to unfixed bugs. However,
upstream GCC have now straightened out the problems, so I have pushed a
buildable version into the branch.
I shall attempt to keep this branch as up-to-date as I can (at least, I
will once the holiday season and January travel are over), but I'll only
push updates if they build for me, so hopefully the branch should remain
fairly stable, at least for our purposes.
Note that so far I've only tested build-ability. Right now I'm not
making any promises about the quality of the compiler.
At some point, we'll want to use this branch to hold our own patches
(both those that will never go upstream, and those that are queued for
GCC 4.7), so it will diverge from upstream 4.6 a bit. For the moment,
it's merely a mirror.
Andrew
== Last Week ==
* Got a new ARM-specific unwind test case working, so its integration
with libunwind stands a marginally better chance of working (once it's
finally finished).
* Sent a ping to binutils mailing list about a patch to improve readelf
that I had sent in at the beginning of December. Still no response.
* Holidays and Vacation
== This Week ==
* Try to finish libunwind integration, as my time with Linaro is nearly
over. Update documentation on wiki to reflect current status.
* Ping ltrace list about a new release. It seemed so close, then the
list went abruptly silent.
--
Zach Welch
CodeSourcery
zwelch(a)codesourcery.com
(650) 331-3385 x743
== Linaro GCC ==
* Continued looking at element/structure load/store intrinsics
improvements. Some good initial results: it looks like the plan of
using "extra-wide" vectors for returning struct results works fine (at
least to a first approximation). Sent off WIP patch (internally to CS
only, so far).
Incidentally this looks like it'll be a good stepping-stone for the
"RTL half" (vs. the "tree half") of the representation of
element/structure loads/stores (e.g. vld2/vst2) also. The return type
(for loads) and argument type (for stores) of the RTL patterns for such
instructions is changed from the current wide-integer representation
(OImode, etc.) to a suitable wide vector instead (e.g. V16QImode). This
change might help lead to a more meaningful mapping from an equivalent
tree form -- though we haven't quite got the whole picture yet, as the
middle-end won't want to know about the ARM-specific and
non-standard-named patterns for the element/structure loads/stores.
(One might imagine a new standard-named RTL expander taking care of that
though.)
== Vacation ==
* Vacation Dec 20th-Jan 4th.
== GCC issues ==
* PR44557, Thumb-1 ICE, looked at the ARM specific secondary reload
parts, as well as some general reload internals context. Concluded that
concerns on Thumb-2 about my submitted patch should be unneeded, as the
reload_in/out patterns should never be used for Thumb-2. Also looked a
bit on how we should upgrade ARM to use TARGET_SECONDARY_RELOAD.
* PR45416, ARM code regression. Started working on this again, cleaning
up patch to submit.
* Had some email discussion with Revital Eres on Swing Modulo Scheduling
(SMS) for ARM issues, mainly on how the doloop_end pattern should be
done on ARM.
* Submitted and committed an obvious small patch for a VFP testsuite case.
== This week ==
* Continue on GCC issues.
* Flying to Dallas on Sunday, prepare for trip.
Hi,
* continued with my attempts to vectorize Viterbi:
- finished implementation of conditional store sinking in cselim
pass (I did only limited testing).
- reconsidered the idea of safe load if-conversion if an adjacent
field of the same structure is accessed unconditionally - this may be
incorrect. Instead I tried the last, not yet committed, patch by
Sebastian Pop that implements if-conversion for such cases of not-safe
data accesses. His patch if-converts the loop in Viterbi, however, it
also makes the loop not vectorizable - additional work should be done
in the data-refs analysis and the vectorizer to make it work.
Sebastian is working on the first part, and I'll help him with the
vectorizer part if necessary.
* analyzed EEMBC DenBench, couldn't find any action items for now. But
vld/vst support of strided data accesses should be very useful for
these benchmarks.
* fixed GCC PR testsuite/47057
* looking into SLP of reduction as in PR 41881. I saw similar patterns
several times in DenBench, but I'm not sure that SLP of reduction is
enough to vectorize all of these cases.
Happy New Year,
Ira
== Last Week ==
* Continue with libunwind. Wrote a new unit test for ARM-specific
unwinding code to help debug that new code's problems. Almost got it
working, which I hope means its integration with libunwind may be
nearing completion.
== This Week ==
* Try to finish ARM-specific improvements to libunwind. Famous Last Words.
--
Zach Welch
CodeSourcery
zwelch(a)codesourcery.com
(650) 331-3385 x743
