== Linaro GCC 4.5 ==
Reviewed, tested and merged all the outstanding patches waiting to go
into Linaro GCC 4.5. Michael reported that there was a build failure on
i686 and amd64. I attempted to reproduce this but my builds completed
successfully - very strange. Eventually I found that I had a corrupted
checkout and managed to reproduce the problem - thanks bzr! The problem
is in Tom's recent changes to stmt.c, so I informed him and backed out
the patches, temporarily.
Spun the Linaro GCC 4.4 and 4.5 release tarballs and passed them to
Michael Hope for final testing.
== GCC 4.6 ==
Tested a more recent version of GCC 4.6 and pushed it to the bazaar
repository. Already out of date by the time testing finished of course,
but never mind. The number of test failures is greatly reduced. Started
another build/test with an even more up-to-date check-out.
Begun work merging the 4.5 patches into 4.6. Pushed 1 patch upstream.
Got another ready to go, once I've tested it.
== Android ==
Tried to unpick a large patch I was sent that supposedly added Android
support to Linaro GCC 4.5. The patch was suspicious from the start
because it had large changes to gcc/ChangeLog that clearly backed out
the 4.5.2 release. After comparing it against various sources I
concluded that it was a 4.6 snapshot from last May with (at least some
of) the Linaro patches forward ported, and the release numbers fudged to
look like it was 4.5.2 based. This was not terribly helpful - I can't
very well backport that into our 4.5 branch!
== Upstream GCC ==
Upstream patches requiring review:
* Thumb2 constants:
http://gcc.gnu.org/ml/gcc-patches/2010-12/msg00652.html
* Kazu's VFP testcases:
http://gcc.gnu.org/ml/gcc-patches/2011-02/msg00128.html
== Last week ==
* Backported the fixes for lp693502, lp710623 and lp710652 to linaro 4.6
and linaro 4.5. Tested and sent merge requests.
* Wrote several more ifunc tests, and fixed the bugs they showed up.
Found that ARM generates unnecessary dynamic relocs against GOT entries,
so fixed that as a prerequisite. Improved the tracking of STB_LOCAL
ifuncs, so that they're treated more like STB_GLOBAL.
* Submitted a request for R_ARM_IRELATIVE to be added to the ARM EABI.
== This week ==
* More ifunc.
I'm away next week (14th-18th)
Richard
Hello,
Matthias noticed the following ICE when attempting to build the SPU
compiler from the Linaro GCC 4.5 sources:
../../../../src-spu/libgcc/../gcc/libgcc2.c: In function '__fixunssfdi':
../../../../src-spu/libgcc/../gcc/libgcc2.c:1344:1: internal compiler
error: in
spu_expand_mov, at config/spu/spu.c:4575
It turns out that this is due to the new "extension elimination" pass that
was recently added in Linaro GCC, as port from the CodeSourcery compiler.
This patch has also been proposed, but not yet included upstream.
The problem is that this patch seems to frequently introduce instructions
that *set* a sub-word lowpart subreg of a register. Now such
instructions, according to the docs, are probably valid RTL, but since the
effect of the instruction onto the highpart of the register is deliberately
left unspecified, they tend to be very infrequently used. Probably
because of this, there seem to be parts of the compiler that simply don't
handle such instructions correctly. This has been already noticed in the
case of the RTL loop optimizers (see discussion here
http://gcc.gnu.org/ml/gcc/2010-11/msg00552.html).
The failure in the SPU back-end is another instance of the same problem.
SPU needs special code to handle subregs (since a "lowpart" SImode subreg
of a DImode register is not actually valid on the SPU, because SImode
values live in bytes 0..3 while DImode values live in bytes 0..7 of the
otherwise big-endian 16-byte SPU registers), and this code simply aborts
when given an assignment to a sub-word lowpart subreg.
Now, I guess there's two ways forward: either the outcome of the ongoing
discussions on gcc-patches is that it is in fact not a good idea to
generate such sets, and the EE pass is subsequently rewritten to avoid
them; or else, if those instructions are considered valid, I'll have to
extend the SPU move expander to handle them. Thoughts?
Matthias, if you need a quick workaround for now, I guess you could disable
the new pass for SPU by adding a line "flag_ee = 0;" to
spu_override_options.
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
I've had a go with running the QEMU release candidate. Short story is
that it boots to a prompt against the 11.05 alpha2 release so I'm
happy.
It was a messy road so I've written up my train of though here:
https://wiki.linaro.org/MichaelHope/Sandbox/QEMU
Note that if you follow the instructions on:
https://wiki.linaro.org/Releases/GettingInstallingTesting
and turn on a swap file then it halts during boot.
-- Michael
== String routines ==
* After some discussions about IT semantics managed to shave a
couple of instructions out of a couple of routines
* Got around to trying a suggestion that was made some months ago,
that LDM is faster than LDRD on A9's; and indeed
it does seem to be in some cases; those cases seem pretty hard to
define though - it's no slower than LDRD, so it seems
best to avoid LDRD.
* Digging around eglibc's build/configure system to see how to add
assembler routines to only get used on certain build
conditions (i.e. v7 & up)
== SPEC ==
* Compiled lbm -O2 and ran it on our local panda and on Michael's
ursa1 - it seems happy (with a drop of swap); so I'd say that
confirms the issues I previously had were local to something on canis.
That's a bit of a pain since it's the only machine with enough
RAM to run the rest of the suite.
== Other ==
* Tested a headless Alpha-2 install on our Beagle C4 - mostly worked
* Tested qemu-linaro release on the realview-pbx kernel/nfs setup I had
* A simple smoke test for pldw on qemu
* Tripped over ltrace not working while trying to profile git's use
of memcpy and memcmp; it does some _very_ odd things;
it's predominant size of memcpy seems to be 1 byte.
== GDB ==
* Prepared Linaro GDB 7.2-2011-02.0 release
* Committed two patches to implement LP #661253 (Improve
backtrace by using ARM exception tables) to mainline and
Linaro GDB 7.2
* Provided two follow-on fixes to the patch for LP #616000
(Handle -fstack-protector prologue code); both applied to
mainline and Linaro GDB 7.2
* Backported mainline fix for LP #685494
(gdb.xml/tdesc-regs.exp failure) to Linaro GDB 7.2
* Identified root cause of LP #711375 (gdb internal error
in inline_frame_this_id trying to debug a qemu target);
committed fix to mainline and Linaro GDB 7.2
* Worked on re-implementation of fix for LP #615978 (Failure
to software single-step into signal handler)
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: DATE/QEMU conference still hasn't confirmed I have a place...
Green: qemu-linaro RC2 prerelease uploaded
Current Milestones:
| Planned | Estimate | Actual |
first qemu-linaro release | 2011-02-08 | 2011-02-08 | |
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 | 2010-01-25 | 2010-01-25 | handed off |
* maintain-beagle-models:
+ RC1 packaging flushed out some bugs:
++ we include some binary blobs which we're better not distributing:
https://bugs.launchpad.net/qemu-linaro/+bug/709965
++ a couple of array overruns don't compile with our picky armel gcc:
https://bugs.launchpad.net/qemu-linaro/+bug/709711https://bugs.launchpad.net/qemu-linaro/+bug/711272
(both fixes sent and applied upstream)
++ we ought to include a fix for the "swp" in qemu-lock.h:
http://patchwork.ozlabs.org/patch/81205/
(patch sent upstream, no comment on it yet)
+ ...so I have rolled an RC2 tarball with these fixed
+ investigated why USB keyboard model doesn't work: it turns out
that the OMAP host USB model is basically just a stub
+ some warnings from qemu about bad width accesses are a symptom of
a nasty disagreement between gcc and the kernel about getting atomic
32 bit accesses:
http://www.spinics.net/lists/arm-kernel/msg113002.html
+ warnings from qemu about access to a nonexistent i2c register
appear to be a kernel bug in the i2c driver for OMAP36xx:
https://bugs.edge.launchpad.net/linux-linaro/+bug/645324
+ investigated a hang running images built with linaro-media-create's
--swap_file option. Still digging but I suspect the Linux driver
doesn't cope with an MMC card which can erase in zero time...
* merge-correctness-fixes
+ the usual upstream mailing list monitoring and code review
+ sent patch for PLI and hint space decoding fixes:
http://patchwork.ozlabs.org/patch/81711/
* misc
+ some non-Linaro time this week; may be more next week
+ some advance planning of what we might want to do with QEMU
in the future
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,
* I continued to setup the pandaboad but ran into #708883
- tested vaious various hwpacks and headless images
- used different power supplies and several SD cards
- built various test kernels from the linux-linaro-natty.git
* looked into the crash utility
* https://wiki.linaro.org/KenWerner/Sandbox/crash-utility#future%20areas
Regards
Ken
