Hi there. I have a custom report on top of the Launchpad tickets that
shows how old they are and if they need attention:
http://ex.seabright.co.nz/helpers/tickets/gcc-linaro?group_by=lint
I check this once a day to see how we're doing. It's useful when
deciding which bug to attack next.
-- Michael
== libunwind ==
* Had few discussions with Uli with regard to unwinding.
* Continued to learn about libunwind internals.
* The .ARM.exidx and .ARM.extbl section parser is functional but the
integration into libunwind needs to be improved. Currently there are two
seperate models that hold the informations of the current frame. Since they
are not synchronized the behavior of libunwind is quite unexpected to the
user.
* I started on eliminating the redundancy by removing the model that was
introduced for the extbl support. My goal is to have the parser operate on the
DWARF model directly. In theory this should also allow to mix DWARF- and
extable-frames.
Regards
Ken
== GCC ==
* Started looking at performance regressions. Setting up builds with
EEMBC Denbench and other benchmarks.
* Looked at PR47719 in some detail this week.
* Set up environment on laptop . Fixed PR46788 in 4.6 branch and trunk.
* Discussions regarding armhf, how to maintain Linaro branches -
upstreaming patches etc.
* Looked at a case of performance improvements with VFP stores. I think
it's because we end up allowing PRE_INC and POST_DEC for floating point
mode values because of which there end up being more transfers to and
from the integer core registers.
* Off sick on Monday 14th March 2011.
== Misc ==
* Sorted out travel arrangements for LDS. Waiting for visa now.
== GDB ==
* Ongoing work on glibc patch to add ARM unwind tables to system
call stubs (bug #684218).
* Implemented initial version of a kernel patch that fixes GDB
inferior calls while stopped in a restartable system call
(bug #615974); started discussion with kernel folks.
* Implemented new version of patch to fix single-stepping over
signal handlers (bug #615978) that addresses review comments;
posted to mailing list.
* Verified Linaro GDB patch set can be applied to Ubuntu package.
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
(sent early this week since I'll be in the conference all Friday)
RAG:
Red:
Amber:
Green:
Current Milestones:
| Planned | Estimate | Actual |
Historical Milestones: [trimmed the 2010 ones]
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 ==
* wrote most of a patch to properly implement prlimit64 syscall
in usermode -- needs checking/testing
* wrote most of a patch to allow boards to specify their min/max/default
RAM size rather than having a single qemu-wide default; this would
let us specify RAM size on the beagle model (currently hardwired)
* retested the patch I wrote late last year which fixes TCG's locking
problems by having interrupting signals/threads just set a flag which
we check in every TB (rather than trying to mess with the TCG graph
in a totally unsafe and crashprone way). Slowdown: about 3.5% on
"boot Linaro nano on vexpress to rootprompt and shutdown again".
I shall see if I can persuade people that this is a price worth
paying for not randomly crashing in thread-heavy code :-)
== merge-correctness-fixes ==
* Wrote/submitted patchset which fixes VRECPS edge case handling
(mostly NaN related)
* Wrote/submitted patchset which fixes Neon VLD of single
element to all lanes
* Wrote/submitted patch which fixes qemu to work on an ARM host
where the host C code has been built in Thumb mode
== other ==
* attended QEMU Users Forum in Grenoble
* meetings: toolchain, standup, pdsw-tools, arch q&a
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Absences:
17/18 March: QEMU Users Forum, Grenoble
Holiday: 22 Apr - 2 May
9-13 May: UDS, Budapest
(maybe) ~17-19 August: QEMU/KVM strand at LinuxCon NA, Vancouver
Short week
* libffi patch accepted upstream
* eglibc integration of string routine changes
- I have something that works but it's more complex than I'd like
(to get it to fall
back to the C code on stuff I haven't optimised for).
* Trying a neon memchr; tried a really simple 8 byte a loop version - it's
quite slow on both A8 and A9; branching on the result of comparisons
done in the neon is not simple.
* Porting jam bug 735877 chromium using d32 float; it was passing
vpfpv3 rather than using the default when configured without neon.
On holiday tomorrow (Friday).
Dave
Hello,
Experiment with aes benchmark from DENbench.
Continue my experiments with SMS which includes re-implementing an old
patch to insert reg-moves in free slots rather than greedily before the
definition as is done in the current implementation.
Thanks,
Revital
Hi,
* submitted store sinking patch to mainline
* started testing auto-detection of vector size patch
* DENBench - some benchmarks are still unstable, I am looking into
stable regressions, adjusting and fixing the cost model for them
Next week:
Sunday and Monday - holidays
Ira
Dave did an investigation earlier in the year into Cortex-A9 and
RealView PBX support in QEMU. The write-up is available here:
https://wiki.linaro.org/WorkingGroups/ToolChain/Outputs/QEMURealViewPBX
Dave and Peter: could you please review it?
I've now closed out the blueprint. I'd like to do similar reports on
other outputs and will attack vexpress next.
-- Michael
Hi Michael, Andrew,
Mounir just pointed out that our non-Ubuntu LP projects (like gcc-linaro,
gdb-linaro etc.) are now also included in the LP work-item tracking
statistics (http://status.linaro.org/linaro-toolchain-wg.html). This
didn't happen in the past due to a Launchpad issue that has now been fixed.
This seems to be working out nicely, except for one issue: what about the
gcc-linaro-tracking project? I have a couple of bugs that are fixed in
Linaro GCC, and are also fixed in mainline GCC, but they still show up as
an "in-progress" work-item in the status tracker (there are a whole bunch
more of those assigned to Andrew as well). The reason for this is the LP
records have an associated gcc-linaro-toolchain project entry, and this is
set to "Fix Committed", but not "Fix Released" ... probably because GCC
4.6.0 is not yet released?
Now, on the one hand it does make sense to include the -tracking project in
the work-item statistics, because they *do* reflect important tasks:
namely, to make sure that the changes indeed land in the upstream
repository. However, having them all show up as "in progress" until the
community makes a new GCC release does not seem very helpful: this is not
in our control, and our work is in fact done once the patch is committed
upstream.
Therefore my suggestion: we should immediately mark -tracking bugs as "Fix
Released" (not "Fix Committed"), as soon as the corresponding patch is
committed upstream (and thus our work on the problem is completed).
Thoughts? Does this make sense? Will this mess up any of the other
purposes for which we currently use the -tracking project?
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 Dave. I had a little play with cortex-strings and did some
benchmarks on my Tegra 2. Images are attached.
I've added two scripts to cortex-strings:
scripts/bench-all.sh runs all the routines on all variants and records them
scripts/plot.py plots the results from above
ploy.py corrects for the benchmark overhead by doing a linear fit to
the null 'bounce' results and subtracting this fit.
You should be able to a autogen; configure; make; bash
scripts/bench-all.sh | tee log.txt; python scripts/plot.py log.txt.
I'm sure you have your own favourite tools though.
The string routines look good. Lumpy in funny ways though...
-- Michael
[Sorry, forgot to CC: the list]
Hi Ira,
Thanks for the feedback.
On 6 March 2011 09:20, Ira Rosen <IRAR(a)il.ibm.com> wrote:
> > So how about the following functions? (Forgive the pascally syntax.)
> >
> > __builtin_load_lanes (REF : array N*M of X)
> > returns array N of vector M of X
> > maps to vldN
> > in practice, the result would be used in assignments of the form:
> > vectorX = ARRAY_REF <result, X>
> >
> > __builtin_store_lanes (VECTORS : array N of vector M of X)
> > returns array N*M of X
> > maps to vstN
> > in practice, the argument would be populated by assignments ofthe
> form:
> > vectorX = ARRAY_REF <result, X>
> >
> > __builtin_load_lane (REF : array N of X,
> > VECTORS : array N of vector M of X,
> > LANE : integer)
> > returns array N of vector M of X
> > maps to vldN_lane
> >
> > __builtin_store_lane (VECTORS : array N of vector M of X,
> > LANE : integer)
> > returns array N of X
> > maps to vstN_lane
> >
>
> How do you distinguish between "multiple structures" and "single structure
> to all lanes"?
Sorry, I'm not sure I understand the question. Could you give a couple
of examples?
The idea is that the arrays above really are array types, regardless of the
actual type of the thing we're accessing (which might be a larger array
than the bounds above say, or which might be an array of structures
or a structure of arrays). That should be OK because arrays alias
their elements.
Richard
Hi Matthias,
in last week's meeting you raised the question what, if any, code from the
Linaro GDB repository could be useful for inclusion into the natty GDB
package. I've now reviewed the contents of the repository, and my
suggestion would be to use everything in Linaro GDB 7.2, except for this
commit (which changes the branding to "Linaro GDB"):
revno: 32969
committer: Ulrich Weigand <uweigand(a)de.ibm.com>
branch nick: 7.2
timestamp: Wed 2010-09-22 19:18:38 +0200
message:
2010-09-22 Ulrich Weigand <uweigand(a)de.ibm.com>
* src-release: Support gdb-linaro packages.
gdb/
* version.in: Set to Linaro GDB version number.
* configure.ac (PKGVERSION, BUGURL): Refer to Linaro.
* configure: Regenerate.
gdb/gdbserver/
* configure.ac (PKGVERSION, BUGURL): Refer to Linaro.
* configure: Regenerate.
gdb/doc/
* configure.ac (PKGVERSION, BUGURL): Refer to Linaro.
* configure: Regenerate.
(Instead, the branding ought to be set as appropriate for the Ubuntu
package. Maybe with an additional reference to Linaro, just as with GCC?)
I've created a snapshot of the Linaro GDB 7.2 branch using the command
bzr diff --prefix a/:b/ -r32965..
and then manually removed changes to
src-release
gdb/version.in
gdb/configure.ac
gdb/configure
gdb/gdbserver/configure.ac
gdb/gdbserver/configure
gdb/doc/configure.ac
gdb/doc/configure
I've left in the new file ChangeLog.linaro for documentation purposes, but
if you prefer this could of course be removed as well.
The resulting patch is appended here. (Note that I'd recommend to continue
updating the patch from Linaro GDB as further changes make it in.)
(See attached file: linaro-gdb.patch)
I've then added the patch to the natty GDB package. Since it touches a
completely distinct set of files compared to the existing list of patches
in the package, it can be added to the series file at any arbitrary point.
I've built the resulting compiler on i386, arm, and ppc64, and it strictly
improved the test results on all three platforms:
i386 without patch:
# of expected passes 16161
# of unexpected failures 114
# of expected failures 72
# of untested testcases 9
# of unresolved testcases 1
# of unsupported tests 69
i386 with patch:
# of expected passes 16331
# of unexpected failures 24
# of expected failures 72
# of untested testcases 9
# of unresolved testcases 1
# of unsupported tests 69
Fixed test case failures are from:
gdb.base/break-interp.exp
gdb.base/foll-fork.exp
gdb.base/printcmds.exp
(These are just test suite cleanups, no actual code changes.)
ppc without patch:
# of expected passes 15350
# of unexpected failures 74
# of expected failures 53
# of untested testcases 15
# of unresolved testcases 1
# of unsupported tests 63
ppc with patch:
# of expected passes 15350
# of unexpected failures 55
# of expected failures 53
# of untested testcases 15
# of unresolved testcases 1
# of unsupported tests 63
Fixed test case failures are from:
gdb.base/printcmds.exp
gdb.threads/local-watch-wrong-thread.exp
gdb.threads/watchthreads.exp
(These are just test suite cleanups, no actual code changes.)
arm without patch:
# of expected passes 15343
# of unexpected failures 270
# of unexpected successes 1
# of expected failures 65
# of untested testcases 11
# of unresolved testcases 2
# of unsupported tests 70
arm with patch:
# of expected passes 15686
# of unexpected failures 46
# of unexpected successes 3
# of expected failures 63
# of untested testcases 11
# of unresolved testcases 1
# of unsupported tests 69
Fixed test case failures are from:
gdb.base/break-interp.exp
gdb.base/corefile.exp
gdb.base/foll-fork.exp
gdb.base/gcore.exp
gdb.base/gdb1555.exp
gdb.base/pr11022.exp
gdb.base/printcmds.exp
gdb.base/recurse.exp
gdb.base/relativedebug.exp
gdb.base/step-test.exp
gdb.base/watch-cond.exp
gdb.base/watch-read.exp
gdb.base/watch_thread_num.exp
gdb.base/watch-vfork.exp
gdb.gdb/selftest.exp
gdb.mi/gdb792.exp
gdb.mi/mi2-syn-frame.exp
gdb.mi/mi2-var-display.exp
gdb.mi/mi2-watch.exp
gdb.mi/mi-syn-frame.exp
gdb.mi/mi-var-display.exp
gdb.mi/mi-watch.exp
gdb.pie/corefile.exp
gdb.server/ext-attach.exp
gdb.threads/attachstop-mt.exp
gdb.threads/attach-stopped.exp
gdb.threads/linux-dp.exp
gdb.threads/local-watch-wrong-thread.exp
gdb.threads/pthread_cond_wait.exp
(This represents much of the bug fix work that went into Linaro GDB.)
Let me know if there's any further information you need, or anything else I
can do to help get the Linaro changes into natty GDB.
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
Merged fixes for several bug into Linaro GCC 4.5. Both from Linaro
(Richard, Matthias and Ramana), and from CS (the shrink wrap problems).
Continued working on benchmarking the patches I've merged to 4.6. Spent
quite some time trying to figure out why EEMBC and the Spec2K weren't
working properly. I've got this sorted now.
Confirmed that the patch to discourage NEON use for integer operations
is still profitable on Cortex-A8. Posted the patch upstream.
Merged upstream GCC 4.6 into Linaro GCC 4.6.
Booked travel to Budapest for Linaro @ UDS.
Followed up on Ramana's questions about the RVCT interoperability patch.
Paul Brook helped explain what it was about, and pointed me at the
proper section in the proper ARM manual.
Continued forward porting patches to 4.6. Mostly I need to convince
myself that they still do something useful. I have posted one new patch
to upstream - the "Discourage A8 NEON" patch.
* Future Absence
Away Wednesday 16th to Friday 18th.
Away Monday 28th to Friday 1st April.
----
Upstream patched requiring review:
* Thumb2 constants:
http://gcc.gnu.org/ml/gcc-patches/2010-12/msg00652.html
* ARM EABI half-precision functions
http://gcc.gnu.org/ml/gcc-patches/2011-02/msg00874.html
* ARM Thumb2 Spill Likely tweak
http://gcc.gnu.org/ml/gcc-patches/2011-02/msg00880.html
* NEON scheduling patch
http://gcc.gnu.org/ml/gcc-patches/2011-02/msg01431.html
* RVCT Interoperability patch
http://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg00059.html
* Discourage NEON on A8
http://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg00576.html
== Last week ==
* Working on Coremark ARMv6 regressions. Identified a major cause being
RTL ifcvt failing on one of the crc routines, due to combine pass
failing to optimize a particular sequence, causing the if-conversion
estimates to give up on conditional executing (too many insns). The
combine pass failed on ARMv6 and above, due to the existence of true
zero_extend insns. On ARMv5, the use of two shifts actually allowed
combine to phase reduce the shifts one by one, thus producing better
code. On ARMv6, combine produced a (xor (and ...) <mask>) which did not
match any insn. Analyzed and sent a patch upstream which should work on
such XOR cases. Patch is due for upstream commit for 4.7-stage1.
(http://gcc.gnu.org/ml/gcc-patches/2011-03/msg00609.html)
* Another situation of un-optimized uxth insns still exists; trying
to solve this by another combine patch I am currently testing, will send
upstream later.
== This week ==
* verify the improvements the above patches should have on Coremark for
ARMv6/v7.
* Work on sending them to Linaro and SG++ branches.
* Other bug issues.
== GDB ==
* Ongoing work on glibc patch to add ARM unwind tables to system
call stubs; ran into design problems that look difficult to fix.
* As an alternative, started work on a GDB patch to recognize glibc
system call assembler stubs via code-scanning; this should allow
alloc unwinding in the absence of debug info for current libc code.
* Analyzed bug #728216 (GDB fails to get a valid backtrace while
debugging a Webkit SIGSEGV) and resolved as invalid; the fault
occurs within JIT-generated code where unwinding is impossible.
== Misc ==
* Made travel arrangements for Linaro Summit in Budapest
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
RAG:
Red:
Amber:
Green: another qemu-linaro release out the door on time
Current Milestones:
| Planned | Estimate | Actual |
qemu-linaro 2011-03 | 2011-03-08 | 2011-03-08 | 2011-03-08 |
Historical Milestones:
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 | 2011-01-25 | 2011-01-25 | handed off |
first qemu-linaro release | 2011-02-08 | 2011-02-08 | 2011-02-08 |
== maintain-beagle-models ==
* released qemu-linaro 2011-03
* had to do a 2011-03-1 reroll of the tarball on day of release to
fix a "versatilepb model crashes on startup" bug found at last minute
* Paul Larson is working on having automated test image boots on
qemu built from git, so we can catch this much earlier in the cycle
== merge-correctness-fixes ==
* added support to risu for testing of load and store instructions
* used this to test a patch which cleans up Thumb load/store decode
and makes us UNDEF in the right places
* wrote/submitted patch to fix GE bits for signed modulo arithmetic
* wrote/submitted patch to get SMUAD/SMLAD Q bit right in an edge case
* started on a patchset which will fix various minor qemu Neon bugs
detected by test programs from the valgrind source tree
== other ==
* meetings: toolchain, standup, pdsw-tools
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Absences:
17/18 March: QEMU Users Forum, Grenoble
Holiday: 22 Apr - 2 May
9-13 May: UDS, Budapest
(maybe) ~17-19 August: QEMU/KVM strand at LinuxCon NA, Vancouver
Hi,
== libunwind ==
* the patches posted last week are now upstream
* continued to study the Exception Handling ABI for the ARM Architecture
* looked into the structure of libunwind (lib interdependencies)
* documented at: https://wiki.linaro.org/KenWerner/Sandbox/libunwind
* The work on the local unwinding appears to be quite complete. If the
generic unwind model is used the code assumes the GCC personality routine. We
should either check name of the symbol (maybe be difficult) or just call the
pers function. I'm in contact with Zach on this.
Regards
Ken
LP: #731665 is a silent bad code generation bug at least on functions
which are empty except for inline assembly:
https://bugs.launchpad.net/ubuntu/+source/gcc-4.5/+bug/731665
It was introduced in the shrink-wrap patch and is due to using an
uninitialised variable. Andrew, can you please address this urgently
either in Linaro or CSL.
-- Michael
== hard-float ==
* Updated libffi variadic patch and Sent updated libffi variadic
patch to the ffi mailing list.
== String routines ==
* Got a big endian build environment going
* Patched up memchr and strlen for big endian; turned out to be a
very small change in the end; and
tested it on qemu-armeb - note that an older version it didn't work
on, but a newer one it did; I'll assume
the newer one is correct.
* Fixed a couple of build issues in the cortex strings test harness
== Other ==
* Kicked off a SPEC2006 train run on canis using the 2011.03 compilers
I'm on holiday tomorrow (Friday) and Monday.
Dave
Hello,
* Sent the patch to support targets
that their doloop part is not decoupled from the rest of the loop's
instructions (as is the case for ARM) to @gcc-patches:
http://gcc.gnu.org/ml/gcc-patches/2011-03/msg00350.html
* Continue looking into DENbench benchmarks.
Thanks,
Revital
Hi,
* continued working on cost model tuning. I don't see much difference
running EEMBC DenBench with and without vectorization enabled (and,
therefore, also with and without cost model).
Also, I have to say, that the results are not stable and I sometimes
get 10% difference just running the same executable two times in a
row.
* the only benchmark I see consistent degradation 5% with
vectorization is DenBench aes, both with GCC trunk and gcc-linaro 4.5.
I found one of the responsible loops, if it is not vectorized I see
only 1.8% degradation. The problem there is that the loop bound is
unknown at compile time, so the vectorizer attempts to vectorize the
loop using runtime guards to verify that there are enough iterations
to vectorize. The actual number of iterations is 4, so the scalar
version of the loop is chosen at the run time, but I guess the guards
cause the degradation. I'll continue looking into this next week.
* prepared the conditional-store-sink patch (one of the patches that
helps to vectorize Telecom Viterbi) for submission to gcc-patches.
Ira
The Linaro Toolchain Working Group is pleased to announce the release
of Linaro QEMU 2011.03-1.
Linaro QEMU 2011.03-1 is the second release of qemu-linaro. Based
off upstream (trunk) qemu, it includes a number of ARM-focused
bug fixes and enhancements.
This release includes a model of the ARM Versatile Express
platform. This is still experimental but may be of use to people
who want a model supporting up to 1GB of RAM with graphics and
networking. Instructions for getting started with it are on the
wiki: https://wiki.linaro.org/PeterMaydell/QemuVersatileExpress
Other interesting changes include:
- The OMAP emulation bug which was causing hangs if Linux tried
to enable a swapfile is fixed
- The OMAP UART model has been improved; this fixes the problem where
kernels using the new omap-hsuart serial drivers stopped serial output
halfway through boot.
- As usual, various minor correctness fixes and other upstream changes
Known issues:
- The beagle and beaglexm models do not support USB, so there is no
keyboard, mouse or networking (#708703)
The only change over the shortlived 2011.03-0 is that the last
minute bug #731093 has been fixed (versatilepb models would crash
on startup.)
The source tarball is available at:
https://launchpad.net/qemu-linaro/+milestone/2011.03-1
Binary builds of this qemu-linaro release are being prepared and
will be available shortly for users of Ubuntu.
When ready, Natty packages of qemu-linaro 2011.03-1 will be in the
Ubuntu archive. Packages for users of Ubuntu 10.04 LTS and Ubuntu
10.10 will be in the linaro-maintainers tools ppa:
https://launchpad.net/~linaro-maintainers/+archive/tools/
More information on Linaro QEMU is available at:
https://launchpad.net/qemu-linaro
Hi all,
I've had comments that getting hold of binaries for the linaro
toolchain can be trick for people unfamiliar with the linaro tools.
One reason is that we don't release binaries as such -- but a visitor
browsing in through http://www.linaro.org/downloads/ won't discover
this, and may waste a lot of time trying to understand launchpad etc.
before coming to the conclusion that binaries either aren't available
or are not easily findable.
On the other hand, the cross toolchain packages are likely to be of
interest to such visitors, but aren't obviously advertised -- maybe
I'm looking in the wrong place, but if so then new visitors to the
linaro pages are likely to look in the wrong place too.
Would it make sense to explain the situation more prominently so that
visitors know what to expect?
Something along the lines of "if you use distro x revision y, these
cross-compiler packages are available" and "if you need the tools for
some other environment, you need to download the source and build it
for yourself".
Cheers
---Dave