Hello Ramana,
For your PGO list:
* please note that I've been working on PGO for switch code, and also
for chains of if-statements with a common condition variable (with Tom
de Vries)
* turning conditional execution off will not make a difference, your
profile information will be exactly the same. Profile instrumentation
happens very early in the pipe line (on purpose, PGO is more
accurately "coverage guided optimization", not profiling in the
prof/gprof/oprofile sense). And the parts of the CFG that have profile
instrumentation cannot be if-converted anyway.
* you can use the script "analyze_brprob" in contrib/ to measure the
accuracy of the branch predictors. The script needs some TLC, fixing
it is on my TODO list but let me know if linaro folks are going to
take care of that. You'll find that the predictors are heavily tuned
towards the original Opteron, I'm not aware of much tuning for other
architectures.
* The heuristics for profile-guided optimizations are also not tuned
for arm. In the past we found that some params have more influence
than others (the TRACER* parameters for example).
Hope this helps,
What do you mean with "Only conditionalise those parts that benefit"?
Ciao!
Steven
== Progress ==
* Looking at auto-inc-dec patches.
* sched-pressure now on by default in FSF 4.8
* Background look into neon costs and vdup improvements.
* Some upstream patch review.
* Discovered http://gcc.gnu.org/PR54051 while testing a neon
intrinsics patch and wrote a patch to fix it.
== Plans ==
* Write a patch to check md5sums between local tarball and uploaded
tarball in the release script.
* Look at auto-inc-dec patches more and investigate benchmark results.
* Finish submitting PR54051 patch upstream.
* Finish vdup folding patch.
The Linaro Toolchain Working Group is pleased to announce the 2012.07
release of the Linaro Toolchain Binaries, a pre-built version of
Linaro GCC and Linaro GDB that runs on generic Linux or Windows and
targets the glibc Linaro Evaluation Build.
Uses include:
* Cross compiling ARM applications from your laptop
* Remote debugging
* Build the Linux kernel for your board
What's included:
* Linaro GCC 4.7 2012.07
* Linaro GDB 7.4 2012.06
* A statically linked gdbserver
* A system root
* Manuals under share/doc/
The system root contains the basic header files and libraries to link
your programs against.
Interesting changes include:
* Change c++, gcc and ld to symlinks in Linux package
The Linux version is supported on Ubuntu 10.04.3 and 12.04, Debian
6.0.2, Fedora 16, openSUSE 12.1, Red Hat Enterprise Linux Workstation
5.7 and later, and should run on any Linux Standard Base 3.0
compatible distribution. Please see the README about running on
x86_64 hosts.
The Windows version is supported on Windows XP Pro SP3, Windows Vista
Business SP2, and Windows 7 Pro SP1.
The binaries and build scripts are available from:
https://launchpad.net/linaro-toolchain-binaries/trunk/2012.07
Need help? Ask a question on https://ask.linaro.org/
Already on Launchpad? Submit a bug at
https://bugs.launchpad.net/linaro-toolchain-binaries
On IRC? See us on #linaro on Freenode.
Other ways that you can contact us or get involved are listed at
https://wiki.linaro.org/GettingInvolved.
We've just started running a weekly benchmark of GCC trunk and Linaro
GCC tip. I've written a short script that compares against a baseline
and spits out a graph:
http://ex.seabright.co.nz/benchmarks/gcc-4.8~svn.pnghttp://ex.seabright.co.nz/benchmarks/gcc-linaro-4.7%2bbzr.png
I'll switch the baseline to GCC 4.7.0 once the build and benchmark run
completes. The gcc-linaro results need more data before they'll make
sense.
Part way there. An automatic email would be next. We should check
the graphs before each performance call.
-- Michael, who needs to get moving on LAVA
== GCC ==
* Checked in fix to LP bug 1020601 (missed optimization with
multiple __builtin_unreachable calls) to Linaro GCC 4.7.
* Implemented and tested alternative fix for incorrect pool
placement with -O0 by splitting all insns in machine-
dependent reorg.
* Continued investigation of reload bug reported by ARM.
== GDB ==
* Tested GDB 7.5 branch on ARM, found a couple of regressions.
Worked on fixing HW breakpoint/watchpoint regressions.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
Current Milestones:
|| || Planned || Estimate || Actual ||
||cp15-rework || 2012-01-06 || 2012-06-23 || 2012-06-24 ||
||a15-lpae-support || 2012-07-13 || 2012-07-20 || 2012-07-20 ||
||clean-up-kvm-patches || || || ||
||track-kvm-abi-changes || || || ||
||fake-trustzone || || || ||
Overall KVM plan for 'do by end August': QEMU parts of this are a mix
of clean-up-kvm-patches and track-kvm-abi-changes blueprints, mostly.
http://cards.linaro.org/browse/CARD-167
== a15-lpae-support ==
* LPAE patches now merged upstream
* v2 of vexpress-large-ram-size sent upstream, code reviewed
and put into arm-devs pullreq. Hasn't hit master yet but
I expect that to happen over the next week.
== clean-up-kvm-patches ==
* squashed together some kvm patches in the qemu-linaro tree
* sent upstream a few patches where we can avoid an ARM-KVM
specific change by instead generalising the upstream code not
to have an explicit list of KVM supporting architectures
* started looking at how best to clean up some working-but-ugly
code handling interrupts in the QEMU KVM-ARM patchset. Among
other problems, this is messy to fix because at the moment
upstream is overloading "is there an in kernel irqchip?" to
mean both "should we use QEMU's irqchip model or not?" and
"is the interrupt injection model synchronous or asynchronous?"
because on x86 they are (for historical reasons) the same.
For ARM we only want to decide which irqchip model to use,
not anything else...
== other ==
* upstream review (various exynos patches, mostly)
* some patches fixing problems with compiler warnings in
configure test fragments
* arm-devs pullreq
KVM blueprint progress tracker:
http://apus.seabright.co.nz/helpers/backlog?group_by=topic&colour_by=state&…
-- PMM
Hi Ramana, Ulrich. Could I have some help with an unexpected
testsuite failure while backporting Carrot's adddi patch?
testsuite/gcc.misc-tests/gcov-7.c builds and runs but aborts during
leave() due to unexpected results.
The merge request is here:
https://code.launchpad.net/~michaelh1/gcc-linaro/core-adddi/+merge/113111
The testsuite diff is here:
http://ex.seabright.co.nz/build/gcc-linaro-4.7+bzr115001~michaelh1~core-add…
The build tree is at:
cbuild@tcpanda02.v:/scratch/cbuild/slave/slaves/tcpanda02/gcc-linaro-4.7+bzr115001~michaelh1~core-adddi/gcc/default/build
The failing and working versions are on tcpanda02 as ~/gcov-7.exe and
~/gcov-7-ok.
Here's the details:
* The test is fine when built from the command line
* The test is fine on the hard float Precise build
* The failing binary works fine when run on Precise
* The disassembled body (not libraries) is identical modulo changes
in addresses
* The fault goes away with a static linking via adding "--tool_opts '-static'"
* The fault persists with binutils 2.22
* The fault persists with the eglibc 2.15 loader
I assume the testsuite picks up a different libgcc and libgcov somehow
which gives a different executable. It's strange that the static
linked version is fine, and that the failing binary works fine on a
different host.
Could you have a poke in the build tree?
-- Michael
== GCC ==
* Tom de Vries fixed root cause of LP bug 1020601 (missed
optimization with multiple __builtin_unreachable calls)
on mainline. Backported to Linaro GCC 4.7 and tested.
Fixed bug exposed by backport (latent in mainline).
* Continued investigation of reload bug reported by ARM.
== Misc ==
* Attended GNU Tools Cauldron in Prague. Presented on
GDB remote/native feature parity work.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
