Hi,
I've run into some compile errors after updating to 4.9 -- usually getting
undefined references to symbols defined in helper static libraries.
It turns out this is triggered by gcc -flto now creating slim object files
by default (-ffat-lto-objects "fixes" it) - but I think it is actually an
ld bug that should be fixed at some point. ld (regardless of whether I use
-fuse-linker-plugin, -fuse-ld=gold or -fuse-ld=bfd) doesn't seem to see LTO
bytecode in object files that are inside an ar wrapper.
It deals with the library just fine if I use "ar x" to extract its object
files and link to them individually as opposed to the .a file.
I've attached a small test case to demonstrate ("make broken" shows the
error, "make works" shows the workaround).
Is there any reason why ld should behave the way it does, or is this a bug
that needs fixing?
ttyl
bero
== Progress ==
* Reload - IRA bug fix (3/10)
Not able to reproduce in trunk, r210538 masks the bug again :(
Discussed with maxim on extending the macro ,Likely spilled class for thumb2.
Decided that it will lead to performance regressions. Conservative fix
is to allow the pattern for ARM target alone. Verfying the fix by on
armhf schroot
* Testing GCC Linaro compiler on Hardware (4/10)
Completed GCC Linaro compiler 4.8 and 4.9 correctness tests on
hardware. Completed running SPEC 2006 for -O3. Completed running
SPEC2006 for -O3 -ftlo and -mcpu=cortex-a57. Triggered PGO runs on
hardware.
Looked at bootstrap failure with BOOT_CFLAGS="-mcpu=cortex-a57".
Changed from system assembler to Linaro assembler solved it as system
assembler is old.
* Misc (3/10)
- Completed installing ubuntu, set up chroot and migrate to toolchain
64 environment. (2/10)
- 1-1 meetings (Ryan, Christophe and Maxim) (1/10)
- AMD internal support work and meetings
== Plan ==
* Continue bug fixing.
* LTO bootstrap failure
* Testing GCC Linaro compiler on hardware.
* UK VISA processing.
== Issues ==
* None
== Progress ==
* CARD-1162 : Linaro GCC 4.9 and CARD-1355 : stabilization and
optimization effort for ARMv8-a (8/10)
- Looked at Jenkins build/failures/reportin
- Review the backporting process and scripted it
- 40 backports are in review and need validation
* LP #1169164 : including signal.h exposes various PSR_MODE #defines
- Committed upstream.
* Misc:
o Various meetings (2/10)
o LCU'14: Register and booked flights
== Next ==
* Child care today
* Improve the backport script and document it's usage
* Continue backports
* Continue feedback and help with the validation
== Progress ==
* GCC trunk cross-validation (4/10)
- build broken last week-end, because of a
new optimization that broke glibc build.
- glibc fixed by Joseph mid-week, updated
- to help diagnose build failures earlier, I have setup
a reduced version of the validation framework,
which only performs a build of binutils+glibc+gcc,
at every commit on gcc trunk for 16 arm+aarch64
configurations. [ yes, another buildbot of sorts ]
- restarted builds+validations to last known successful
status (i.e. before last week-end)
- builds are catching up
* Neon intrinsics tests (3/10)
- continuing conversion (about 40 files done, out of ~140)
* Misc (meetings, conf-calls, ...) (3/10)
* Backports for 4.9:
- started reviewing candidate backports
== Next ==
* GCC trunk cross-build/cross-validation:
- monitor and report regressions
* Neon intrinsics tests:
- continue conversion
- prepare a cleaner branch for upstream submission
* Backports:
- more reviews
- process improvements
== Progress ==
* Kernel (CARD-1246 4/10)
- Named registers committed in Clang
- GCC seems to break on local named regs, too.
- Trying to change the kernel code to use only globals for non-GPRs
- Adding support for pointer types, and structure fields in GNRVs
* Benchmarks (CARD-716 0/10)
- Re-enabling perf reports for LNT bot (ARM fixed reporting)
* Background (6/10)
- Code review, meetings, discussions, etc.
- Removing *all* buildbots' batteries after failure
- Testing D01 box, not stable yet for toolchain testing
- Moving development to git.linaro.org (for backup)
- Planning TCWG rack migration
- Drafting an LLVM white paper
== Plan ==
* Continue with named register extra work (http://llvm.org/PR19837)
* Start TCWG rack migration
* Discussions about LLVM white paper
== Progress ==
* Investigate and fix building glibc for ARM with -mtls-dialect=gnu2 (3/10)
* Investigate ld TLS behaviour for Huawei (1/10)
* Refactor scripts to enable benchmarking postgresql malloc
performance (2/10, TCWG-441)
* Patch review and testing (1/10)
* Diagnose and fix glibc testsuite failures on aarch64 (2/10)
* Meetings, admin (1/10)
== Issues ==
* None
== Plan ==
* More malloc application benchmarking
--
Will Newton
Toolchain Working Group, Linaro
== Progress==
lowlevellock performance bugs - TCWG-435 [5/10]
* Tried various methods to build/test glibc for aarch64
* Eventually succeeded (tests passed)
cbuild benchmarking - TCWG-360 [3/10]
* cbuildized spec2xxx scripts working as far as 'run'
Meetings/mail/etc [2/10]
== Plan ==
Holiday for one week
After that:
* Clean up cbuildized spec2xxx scripts, cbuildize them some more &
discuss with Rob
* Send lowlevellock patch upstream
* If time, put together some more experimental memset implementations
I have been thinking how to simplify cross-testing our toolchain for both automated and development/debugging builds, and among various options the most universal I came up with is ARM hardware + ssh + binfmt_misc + sshfs. I wonder if anyone has already tried this or can suggest alternatives which are as universal.
Given:
- host x86_64 development machine
- cross-compiler
- target hardware with fast network to the host
- host and target have ssh
- testsuite (gcc/glibc/gdb/etc)
Here is how it is going to work
1. On host we create a simple wrapper script that will pass through its arguments as command to execute on target via ssh:
===
#!/bin/sh
ssh -p 22NN $TARGET_BOARD "$@"
===
2. We register this script in binfmt_misc to be used as interpreter for target binaries. Value of $TARGET_BOARD will be picked up from the environment and can be set to different boards for different testsuite runs.
3. The target board needs to be prepared for a particular testsuite run:
-- Runtime libraries need to be either copied or mounted via sshfs from the host. It is an open question how best to install several sets of libraries (for parallel runs) so that each set appears to be main system libraries. My current thinking is a separate ssh server inside chroot per each test run.
-- Test directory needs to be sshfs mounted on target from host so that the target could see test executables.
-- Preparation/finalization of the board can either be done explicitly before/after testing. Or it can be done on demand by the aforementioned script: the script checks whether a multiplexed ssh socket exists, and, if not, it prepares the board and starts a multiplexed ssh connection.
4. Testing is fired up as if it is normal "native" testing. Whenever kernel is given an ARM binary to execute -- it passes it off to wrapper, which passes it off to the target board via ssh. The board sees same filesystem as host and happily executes binaries against toolchain runtime libraries.
Comments or rotten tomatoes?
Thank you,
--
Maxim Kuvyrkov
www.linaro.org
= Progress ==
* Worked on the LLVM branch of Cbuildv2 (TCWG - 1/10).
* More work on regression test analysis and reporting. (TCWG 448 - 5/10)
* Meetings and Misc (4/10)
- Produced lots of test results via Jenkins, need to verify
they're not having remote target problems.
== Plan ==
* Verify test runs aren't having problems with remote targets.
* Start training the Jenkins Failure Analysis plugin.
* Install lava-tool and get it working on all the tcwgbuild* machines.
* Continuing work on regression test analysis and reporting. (TCWG
448 - 5/10)
