The Linaro Toolchain Working Group is pleased to announce the release of
both Linaro GCC 4.6 and Linaro GCC 4.5.
Linaro GCC 4.6 is the fifth release in the 4.6 series. Based off the latest
GCC 4.6.1+svn175677, it adds new optimisations and vectoriser improvements.
Interesting changes include:
* Updates to 4.6.1+r175677
* Improves support for vector shifts by a constant
* Improves handling of memory dependencies in the SMS optimisation
* Improved vectorisation of widening multiplies by keeping the operands
smaller for longer
* Improves the peeling of potentially misaligned vectorised loops
* Improved vectorisation of signed and unsigned widening multiplies by a
constant
* Merges the new upstream Cortex-A5 tuning
Fixes:
* LP: #721531: Don't optimise out testing of the Thumb mode bit on function
pointers
* LP: #723185: ICE in reload_cse_simplify_operands when compiling with -marm
-mfpu=neon
* LP: #744754: ICE in *neon_movoi when using NEON intrinsics
* LP: #791327: ICE due to using the stack pointer in RSB instructions
* LP: #797748: ICE building SPEC2006 403.gcc emit-rtl.c
* LP: #803232: ICE on code that uses vld4q_s16() NEON intrinsic
* LP: #809435: Omit building the target libiberty when building a cross
compiler
* LP: #807573: ICE in *truncsisf2_vfp: Could not find a spill register
* PR 49385: Ensure at least one of the operands is a register in
thumb2_movhi_insn
* Fixes an EABI unwinding bug that improves interoperability with armcc
* Fixes a DWARF 2 problem exposed through shrinkwrap.
* Fixes a bug in __builtin_isgreaterequal
Known issues:
* Building Python 2.7 with -mfpu=neon exposes a bug in vmov.i64 in binutils
2.20.51. Please use 2.21 or later.
Linaro GCC 4.5 2011.07 is the twelfth release in the 4.5 series. Based off
the latest GCC 4.5.3+svn175676, the release is focused on maintenance.
Interesting changes in 4.5 include:
* Updates to 4.5.3+r175676
Fixes:
* LP: #721531: Don't optimise out testing of the Thumb mode bit on function
pointers
* LP: #723185: ICE in reload_cse_simplify_operands when compiling with -marm
-mfpu=neon
* LP: #744754: ICE in *neon_movoi when using NEON intrinsics
* LP: #797748: ICE building SPEC2006 403.gcc emit-rtl.c
* LP: #803232: ICE on code that uses vld4q_s16() NEON intrinsic
* Fixes a DWARF 2 problem exposed through shrinkwrap.
The source tarball is available from:
https://launchpad.net/gcc-linaro/+milestone/4.6-2011.07https://launchpad.net/gcc-linaro/+milestone/4.5-2011.07
Downloads are available from the Linaro GCC page on Launchpad:
https://launchpad.net/gcc-linaro
Mailing list: http://lists.linaro.org/mailman/listinfo/linaro-toolchain
Bugs: https://bugs.launchpad.net/gcc-linaro/
Questions? https://ask.linaro.org/
Interested in commercial support? inquire at support(a)linaro.org
-- Michael
Hi,
- I finally submitted the over-widening patch, but Richard Guenther
thought that this optimization should be done for scalars as well, and
he is now working on this himself.
- Some auto-vectorizer fixes
Ira
The Linaro Toolchain Working Group is pleased to announce the release
of Linaro QEMU 2011.07.
Linaro QEMU 2011.07-0 is the latest monthly release of qemu-linaro. Based
off upstream (trunk) QEMU, it includes a number of ARM-focused bug fixes
and enhancements.
This month's release is primarily minor improvements:
- Fixes a compile failure on ia64 hosts
- syscall 369 (prlimit64) implemented in linux-user mode
- Fixes an ELF loader bug that caused problems with binaries generated
by the Google Go compiler
Plus of course new upstream fixes and improvements.
Known issues:
- The beagle and beaglexm models still do not support USB networking
- Very recent Linaro omap3 hwpacks (20110716 and later) do not boot on
the beagle model; this is caused by an x-loader bug (LP:813407)
The source tarball is available at:
https://launchpad.net/qemu-linaro/+milestone/2011.07
Binary builds of this qemu-linaro release are being prepared and
will be available shortly for users of Ubuntu. Packages 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,
Apologies for missing the stand-up call today.
I've been having technical difficulties at my end. :(
I think they're resolved now ... maybe.
Andrew
Hi,
* continued to look into #809768 (ICE when building bionic's libm)
* created some toolchain and android builds for verification purposes
* libunwind
* discussions with Michael and Uli on how to proceed (thanks!)
* started to work on libunwind-ptrace
* also look for .debug_frame info if there is no .eh_frame info
for the given IP
* mimics the behaviour of the reworked local unwinding
* Attended an IBM internal class on Wednesday
Note: I'm off for two days (21-22) and back on Monday.
Regards
Ken
Hi there. The 2011.07 release has been spun and is testing up well.
The 4.5 and 4.6 branches are now open so feel free to commit any
approved patches.
-- Michael
== GCC ==
=== Progress ===
* Identified particular patterns that have issues with scheduler
descriptions in A8 and A9 . Fixes to be benchmarked next.
* Spent sometime on the new tree-reassoc work but SPEC2k failed for
some of the neon configurations. Needs investigation.
* T2 perf call.
* Looked at libquantum bits with Revital.
* BRANCH_COST benchmarking now complete for T2 . Same is running for ARM state.
* Some patch review and bugzilla triaging upstream.
=== Plans ===
* ivopts patch for RichardS to try out - related to the excessive
moves between integer and VFP unit.
* BRANCH_COST further results.
* Submit scheduler patches upstream after benchmarking.
Meetings:
* 1-1s
* TCWG calls
Absences.
* 1st Aug - 5th August - Linaro sprint.
* 8th - 9th August -Internal training.
* 29th Aug - Sept. 2 - Holiday booked and approved.
* 31st Oct - 4th Nov - Linaro Summit Orlando - Travel to be booked.
Continued responding to review comments on my widening multiply patches.
Wrote large parts of most of the patches to fix bugs and tidy them up.
The result is that all but patch 1 are now approved. Pushed the patches
to Launchpad for final testing.
Monitored the test status of my thumb2 constants patch, but it still
hasn't returned any results. It seems Michael has been having some
problems with his systems.
Went back to looking at merging patches to 4.6. It's only really the
hard ones left. Many are blocked on work that needs to be done by
somebody else. Pinged Tom and Bernd to find out the status of their ones
- all are stuck on the back burner.
----
Upstream patched requiring review:
* NEON scheduling patch
http://gcc.gnu.org/ml/gcc-patches/2011-02/msg01431.html
* Widening Multiplies 1/7
http://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg08721.html
- Tracked the problematic file which contains the loop that causing
bootstrap failure with SMS flags on ARM machine. It is not caused by
SMS but rather due to doloop optimization which is applied when SMS
flags are set. Now working on locating the exact loop and producing a
testcase to reproduce the error.
- Looking into Spec2006/libquantum benchmark - it has hot loop with
conditional store which suppress SMS as it is only applied on single
basic-block loops. If-conversion can not be done (replacing the store
with conditional move and then a store) because in order to do that we
need to prove that there is a store to the same location in each
iteration of the loop; and it is not the case in this loop.
Apparently, when running with crotex-a8 flag cond_exe statement is
generated for the store but that's happening only after register
allocation pass which is applied after SMS (IIUC,moving the generation
of cond_exe before RA is not trivial
http://gcc.gnu.org/ml/gcc/2000-05/msg00079.html)
So, I'm looking into teaching SMS to handle conditional statements
based on technique presented in [1]. This change is not trivial so I'm
going to estimate the potential of applying SMS on the loop at first
stage.
[1] M. Lam, "Software pipelining: an effective scheduling technique
for VLIW machines"
