== Last week ==
* CoreMark regressions: pushed a merge of my two upstream patches to
Linaro 4.5, some current numbers are here:
http://lists.linaro.org/pipermail/linaro-toolchain/2011-April/001087.html.
* Continued working on another combine patch for improving CoreMark,
hopefully ready to submit this week.
* Committed fix for PR48325 (NEON POST_INC/PRE_DEC load/stores for
struct modes) upstream.
* Committed fix for PR48250 / Launchpad #723185 upstream.
* Launchpad #689887, ICE in get_arm_condition_code(). My prior patch was
tested to cause native bootstrap failure on Linaro 4.5, though retesting
on upstream trunk worked fine. Still investigating.
* Booked travel for Linaro-Budapest event.
== This week ==
* Current combine patch.
* Some unresolved patches, like PR46888.
* Launchpad #689887, hope to figure this out.
I've started up a page with ideas for sessions at next month's summit:
https://wiki.linaro.org/MichaelHope/Sandbox/1111Blueprints
They're a pretty direct map to the TSC technical topics so far which
is nice to see. Feel free to add other ideas to the page. Each
session is around 45 minutes, needs to be fairly well understood by
the drafter beforehand, and should have concrete actions coming out of
it. It's fine to have a few future/blue sky sessions but not too
many.
We'll discuss these at tonights meeting and assign drafters.
-- Michael
I've now submitted the initial vldN and vstN work, so I thought I'd see
how often it triggers for natty's libav package. I've put some initial
results here:
https://wiki.linaro.org/RichardSandiford/Sandbox/NeonLibAv
There are more files to go through, so this isn't complete.
I've also left out cases that were very similar to the ones given.
Some of the code is reasonable, while others are obviously not as good
as they could be. I don't think the problems are really to do with
the vldN and vstN work itself though. They seem to be due to the
underlying interleaved load/store detection, or in the handling
of widening operations.
Richard
== Bug triaging ==
* Bug 745843 (vtk ftbfs) got it down to a bad arm/thumb transition -
identified as a linker error and handed off to RichardS
* Bug 758082 (augeas ftbfs) tracked it down to overwrite of a
parameter in a variadic function before it got stacked; identified by
Ramana as another
instance of the shrink-wrap bug.
* Bug 745861 (petsc ftbfs) isolated the collection of different mpi
related problems this is hitting; really need to find an mpi expert on
this
* Bug 745863 & bug 745891 (ftbfs's) - both were compilations that
timed out; verified this was due to using lots of RAM and also using
lots of RAM on x86
(> ~500MB) - marked as invalid until the build farm grows more RAM
* Bug 757427 gconf seg fault - failed to reproduce under various
tests (although Michael has now managed to catch it in the act)
== Optimisation ==
* neon memcpy tweeking; added prefetches and unrolled the core loop
- now comparable perf to bionic memcpy in most cases (slower on
misaligned destination, faster in other cases)
* tweaked latrace to print address/length of argument strings so I
can get some stats on routine usage.
Dave
== This week ==
* Worked on a fix for https://bugs.launchpad.net/gcc-linaro/+bug/758082
Submitted the patch upstream.
* Finished first cut of vldN and vstN vectorisation. Send the patches
upstream. Most of the patches have been approved, but I'll wait for
the others before committing.
* Looked at how the vectoriser handles natty's libav. Found some nice
loops, some OK-but-could-do-better, and some really atrocious.
Wrote up the results here:
https://wiki.linaro.org/RichardSandiford/Sandbox/NeonLibAv
* Started writing micro benchmarks for each loop on that page.
I'm about half way through now (starting from the bottom).
* Started looking at whether the changes affect DENbench.
* Patch review.
* Wrote a small follow-up to the fix for LP 758082.
* Some patch pinging.
== Next week ==
* More micro benchmarks.
* More DENbench.
* Submit a merge request for the intrinsics improvements, if the
remaining patches are approved.
* Look at the poorer libav loops in more detail.
Richard
RAG:
Red:
Amber:
Green: now only 6 "core ARM emulation" patches in qemu-linaro not
yet upstreamed (still lots of omap3 patches, though)
Current Milestones:
| Planned | Estimate | Actual |
qemu-linaro 2011-04 | 2011-04-21 | 2011-04-21 | |
Historical Milestones:
finish qemu-cont-integration | 2011-01-25 | 2011-01-25 | handed off |
first qemu-linaro release | 2011-02-08 | 2011-02-08 | 2011-02-08 |
qemu-linaro 2011-03 | 2011-03-08 | 2011-03-08 | 2011-03-08 |
== maintain-beagle-models ==
* some early prep for next week's qemu-linaro release
== merge-correctness-fixes ==
* patch to fix Neon UNDEFs sent upstream and committed
* patch fixing an overflow in signed VABAL.s32 upstreamed, committed
* investigated a bug report which turns out to be that if you try
to single step over an instruction which UNDEFs using qemu's gdb
stub we execute the insn at the UNDEF vector and stop after it
rather than stopping at the UNDEF vector
* some investigation of qemu mishandling of FP exception flag setting;
putting this on hold though, as it really isn't very high priority
* reviewed patches from Aurelien doing some general softfloat cleanup
== other ==
* trying to nail down proposed QEMU work for next cycle;
work-in-progress: https://wiki.linaro.org/PeterMaydell/Qemu1111
* two IRC interviews for QEMU Google Summer of Code student to
do some work on upstreaming of the Android emulator device models
* meetings: toolchain, standup, architecture Q&A, divisional update
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Absences:
Holiday: 22 Apr - 2 May
9-13 May: UDS, Budapest
(maybe) 15-16 August: QEMU/KVM strand at LinuxCon NA, Vancouver
[LinuxCon proper follows on 17-19th]
Hi, I've just pushed a merge of the current upstream patches for
resolving the CoreMark regressions.
(https://code.launchpad.net/~cltang/gcc-linaro/coremark-part1)
To give a quick benchmark of the current status, testing Linaro 4.5
before/after the merge of those two patches:
Optimization options used were just plain '-O2 -mtune=cortex-a9', tested
on one of our Pandaboards running Maverick; all numbers are
Iterations/Sec averaged from 3 runs.
r99492 r9942+patches improve %
-march=armv5te 2786.87 2848.12 2.20 %
-march=armv7-a 2474.50 2775.92 12.18 %
-march=armv7-a -mthumb 2297.86 2356.59 2.56 %
I'll have to re-test to be sure, but the numbers/improvements obtained
using upstream trunk should not be too far off, at least the ARM mode ones.
As we discussed in prior meetings, there's still one point of regression
identified that's in solving, which hopefully will finally bring the
ARMv7-A numbers above ARMv5TE.
Chung-Lin
Hello,
- Tracking down bugs exposed while testing a patch for SMS to avoid
using -fauto-inc-dec flag and preparing fixes for them.
Also, prepared a fix for PR47013.
- Continue looking into DENbench and updating
https://wiki.linaro.org/Internal/ToolChain/Benchmarks.
Thanks,
Revital
== GCC ==
Progress:
* Spent some time digging into binutils issue for Neon but still not
sure why I see the problem when this is fixed in 2.21 branch and no one
else see this.
* Fixed PR 48090 upstream.
* Some patch review.
* T2 performance meeting.
Plans when I'm back:
* Continue looking at divmodsi4 improvements.
* Continue looking at excessive VFP moves.
* Backport the fix for the initialization of cgraph into FSF 4.5 branch.
Meetings:
* 1-1s
* Linaro toolchain meeting
* T2 performance.
* Linaro@UDS meeting.
Absences:
* April 15 – 26 -> Booked.
* May 9-14 - LDS Budapest
hey
This problem with busybox:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=621137
seems to be a toolchain issue.
It occurs with FSF GCC 4.5.2 but not 4.6, and it doesn't occur with
Linaro GCC 4.5 but it does with Debian gcc-4.5. I'm trying to identify
the fix which Linaro applied to solve this! :-) Michael Hope told me
he remembers we fixed something similar for Qt, but he couldn't find
the patch and suggested I post here to get feedback.
I've pushed ash.i and .s at:
http://people.linaro.org/~lool/ash.i
which you can build with:
gcc -save-temps -std=gnu99 -Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Wunused -Wunused-parameter -Wunused-function -Wunused-value -Wmissing-prototypes -Wmissing-declarations -Wdeclaration-after-statement -Wold-style-definition -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections -fno-guess-branch-probability -funsigned-char -static-libgcc -falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1 -g -Os -c -o ash2.o ash.i
the interesting part is that ash.s has tryexec as not returning, when
it does return:
grep ^tryexec ash.s -A5 | grep return
this seems to be due to the combination of tryexec being static, its
parent being noreturn, and one argument of tryexec being unused.
Any idea of which Linaro patch solved this? :-)
Does it make sense to raise this to FSF GCC 4.5?
Thanks!
--
Loïc Minier
