* Linaro
Continued trying to understand lower-subreg and its impact on ARM
optimization. After much staring at RTL dumps and trying to minimize
test cases from large code bases I've not found an example of code where
disabling the lowering of pseudo-to-pseudo copies made the code larger
for anything other than unfortunate random knock-on effects (such as no
longer being able to use 16-bit thumb1 opcodes). I posted a message to
this effect on the gcc list, and I'll try benchmarking a patch for this
next week.
In the process of looking at lower-subreg, discovered a silly
missed-optimization bug with many DImode operations, and reported it to
GCC Bugzilla as pr53189.
Hi,
OpenEmbedded-Core/meta-linaro:
* created meta-linaro denzil branch to be used in conjunction with the
oe release
* added a patch that prevents GCC from installing libssp and
libstdc++-v3 to lib64 on X86_64 Linux
* merged patches that use vexpress defconfig only for qemuarmv7a
* built and tested all supported QEMU tarted (ARM, MIPS, PPC, X86,
X86_64) using Linaro GCC 4.6 2012.04
* All images (minimal, sato and Qt) are booting!
* started to work on the automation
Regards,
Ken
Summary:
* arm-linux-gnueabihf and multilib support for linaro toolchain.
* Code size benchmark analysis.
Details:
1. arm-linux-gnueabihf support for linaro toolchain
* Update gcc, libgcc and libstdc++ config to support the triplet.
* Update build scripts to gnueabihf.
* Add sample config for gnueabihf.
2. Multilib support for linaro toolchain
* Merge Terry's multilib patches
(http://gcc.gnu.org/ml/gcc-patches/2012-04/msg00975.htmlhttp://gcc.gnu.org/ml/gcc-patches/2012-05/msg00083.html) and revise
them for linaro.
* Update gcc.c and incpath.c to make multiarch and multilib work together.
* libgcc for armv4t (-mfloat-abi=soft) build fail: ld: error:
armv4t/libgcc_s.so.1.tmp uses VFP register arguments, ... does not.
Root cause: crt*.o from precise sysroot use VFP_args, while other
objects are built with -mfloat-abi=soft. We need additional crt*.o to
build libgcc for armv4t.
3. Code size regression analysis
We find more regression cases introduced by ivopt and loop invariant.
Plans:
* Investigate other code size regressions in 4.7.
* Finalize the arm-linux-gnueabihf and multilib support for linaro toolchain.
Best regards!
-Zhenqiang
I've lost track of the benchmark builds so I've started a manual todo list at:
https://wiki.linaro.org/MichaelHope/Sandbox/Todo
It's been messy with the validation lab being down and some builds
being in my home office and some in Cambridge. Let me know if I'm
missing any.
-- Michael
Hi folks,
We really need to push on with getting the loader path for armhf
standardised. The path that was agreed months ago is
/lib/arm-linux-gnueabihf/ld-linux.so.3
but clearly not everybody is using that yet. Dann has just posted an
updated patch for gcc, and we want to get this reviewed / fixed up /
accepted ASAP. Then we may need to backport it to older gcc releases.
This is *important* so that we can help vendors release binaries that
work on any hard-float distribution. For people who have made binaries
that still use the old, broken location /lib/ld-linux.so.3, we can put
symlinks in place *for now* but in the longer term as many distros
switch to multi-arch the symlink is not an acceptable solution.
I'm working on a more complete spec document for armhf to help us with
this kind of thing, but it's not going as smoothly as I'd hoped and I
don't want to wait for that as a blocker on the linker path.
Cheers,
--
Steve McIntyre steve.mcintyre(a)linaro.org
<http://www.linaro.org/> Linaro.org | Open source software for ARM SoCs
Current Milestones:
|| || Planned || Estimate || Actual ||
||cp15-rework || 2012-01-06 || 2012-06-23 || ||
Historical Milestones:
||initial-a15-system-model || 2012-01-27 || 2012-01-27 || 2012-01-17 ||
||qemu-kvm-getting-started || 2012-03-04?|| 2012-03-04 || 2012-02-01 ||
== other ==
* cleaned up and refactored QEMU GIC/NVIC code enough to provide
a solid foundation for the in-kernel irqchip support. Posted
the refactoring bits to qemu-devel. This should be enough to
unblock Marc Z.
* qemu-linaro: LP:978694: added patch from Peter Chubb fixing
beagle bootrom FAT12/FAT16 handling
* finished a trivial bit of cleanup of an omap3 ID register patch
I'd had lying around half-done for a while
* investigating a bug reported by Alex Graf where we get a segfault
gtk-query-immodules-2.0 but only if qemu's 'reserve memory space'
feature is being used: this appears to be an interestingly nasty
case where if the guest does mmap(dll); execute code in dll;
munmap(); mmap(dll 2); execute code in dll 2; and the two mmap()s
happened to pick the same address then we will end up using a
stale cached translation from dll 1 when executing dll 2...
-- PMM
== GCC ==
* Completed testing and benchmarking of patch to use vld1/vstd1
instead of vldm/vstdm for vector moves. Saw no regressions but
only minor benefits.
* Checked in patch to fix LP #959242 (GCC PR tree-optimization/52633)
to FSF mainline and 4.7 branch; backports to Linaro GCC 4.7 and 4.6
pending.
* Checked in mainline patch to enable -fsched-pressure by default
on s390.
* Ongoing work on improving end-of-loop value computation.
* Started investigation of TSVC vectorizer test kernels.
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
Hi Uli,
While looking into something else I ran into these - I wonder how many
of these GCC manages to vectorize ...
http://www.netlib.org/benchmark/livermorec . These look interesting
from a vectorizer kernels point of view.
The other interesting paper of note was this PACT paper on
vectorization benchmarks comparing icc , xlc and GCC which might
provide some interesting hints / reading.
http://polaris.cs.uiuc.edu/~garzaran/doc/pact11.pdf . The appropriate
benchmarks kernels are linked to below.
http://polaris.cs.uiuc.edu/ ̃maleki1/TSVC.tar.gz.
regards,
Ramana
I've put the agenda for Monday's call at:
https://wiki.linaro.org/WorkingGroups/ToolChain/Meetings/2012-05-07
which is:
* Review action items from last meeting
* Connect sessions:
* GDB for Android
* GCC performance call - Live!
* KVM performance
* Renderscript
* Android benchmarking
* Dalvik improvements
* Hard float switchover status
* multiarch upstreaming
* Next week is release week
* vld1, EEMBC results, and noise
* twolf result variance
* KVM minimum features
* UP/UP, Ubuntu
* [[MichaelHope/Sandbox/KVMUseCase]]
Feel free to edit,
-- Michael
