Andrew Stubbs

  • Reviewed and approved Revital's do-loop patch, and Ira's store sinking patch. More precisely, I reviewed the test results from Michael's test system, and cast my eye over the patch to look for anything obvious. I don't pretend to know exactly what they do.
  • Attended Ramana's thumb2 optimization discussion.
  • Continued work on merging useful patches from CodeSourcery. Pushed the new patch set to Launchpad for testing in Michael's system.

  • Pointed Bernd at lp:758082 - another probable shrink-wrap failure. Bernd responded with a new patch, and asked me to test it. I've pushed it to Launchpad and created a merge request.
  • Posted an old patch of Dan's upstream:

  • Pinged my thumb2 constants patch upstream. Richard E responded with some issues to address. I'll need to change the names of the constraints, at least.
  • At Ramana's request, tested the NEON scheduling patch with SPEC2000. Encountered trouble with time-outs. Fixed those and retested.
  • Posted an updated version of my EABI half-precision patch:

  • Merged my backport of Julian's -fstrict-volatile-bitfields bug fix into Linaro GCC.
  • The testing of the Android patches came back with a few test differences, but they appear to be unrelated to the patch, so are probably environmental. I've merged the changes to Linaro GCC.
  • [Also spent most of Friday working on internal CS tasks.]

Chung-Lin Tang

Last week

  • CoreMark regressions: pushed a merge of my two upstream patches to Linaro 4.5, some current numbers are here:

  • Continued working on another combine patch for improving CoreMark, hopefully ready to submit this week.

  • Committed fix for PR48325 (NEON POST_INC/PRE_DEC load/stores for struct modes) upstream.
  • Committed fix for PR48250 / Launchpad #723185 upstream.
  • Launchpad #689887, ICE in get_arm_condition_code(). My prior patch was tested to cause native bootstrap failure on Linaro 4.5, though retesting on upstream trunk worked fine. Still investigating.
  • Booked travel for Linaro-Budapest event.

This week

  • Current combine patch.
  • Some unresolved patches, like PR46888.
  • Launchpad #689887, hope to figure this out.

Dave Gilbert

Bug triaging

  • Bug 745843 (vtk ftbfs) got it down to a bad arm/thumb transition - identified as a linker error and handed off to RichardS
  • Bug 758082 (augeas ftbfs) tracked it down to overwrite of a parameter in a variadic function before it got stacked; identified by Ramana as another instance of the shrink-wrap bug.
  • Bug 745861 (petsc ftbfs) isolated the collection of different mpi related problems this is hitting; really need to find an mpi expert on this
  • Bug 745863 & bug 745891 (ftbfs's) - both were compilations that timed out; verified this was due to using lots of RAM and also using lots of RAM on x86 (> ~500MB) - marked as invalid until the build farm grows more RAM

  • Bug 757427 gconf seg fault - failed to reproduce under various tests (although Michael has now managed to catch it in the act)


  • neon memcpy tweeking; added prefetches and unrolled the core loop
    • now comparable perf to bionic memcpy in most cases (slower on misaligned destination, faster in other cases)
  • tweaked latrace to print address/length of argument strings so I can get some stats on routine usage.

Ira Rosen

Ken Werner



  • gdb doesn't find separate debug info of libraries that have been put into a multiarch directory (#758619)

Marcin Juszkiewicz

Michael Hope

Mounir Bsaibes

Peter Maydell


  • some early prep for next week's qemu-linaro release


  • patch to fix Neon UNDEFs sent upstream and committed
  • patch fixing an overflow in signed VABAL.s32 upstreamed, committed
  • investigated a bug report which turns out to be that if you try to single step over an instruction which UNDEFs using qemu's gdb stub we execute the insn at the UNDEF vector and stop after it rather than stopping at the UNDEF vector
  • some investigation of qemu mishandling of FP exception flag setting; putting this on hold though, as it really isn't very high priority
  • reviewed patches from Aurelien doing some general softfloat cleanup


  • trying to nail down proposed QEMU work for next cycle; work-in-progress:

  • two IRC interviews for QEMU Google Summer of Code student to do some work on upstreaming of the Android emulator device models
  • meetings: toolchain, standup, architecture Q&A, divisional update

Ramana Radhakrishnan


  • Spent some time digging into binutils issue for Neon but still not sure why I see the problem when this is fixed in 2.21 branch and no one else see this.
  • Fixed PR 48090 upstream.
  • Some patch review.
  • T2 performance meeting.

Plans when I'm back:

  • Continue looking at divmodsi4 improvements.
  • Continue looking at excessive VFP moves.
  • Backport the fix for the initialization of cgraph into FSF 4.5 branch.


  • 1-1s
  • Linaro toolchain meeting
  • T2 performance.
  • Linaro@UDS meeting.


  • April 15 – 26 -> Booked.

  • May 9-14 - LDS Budapest

Revital Eres

Richard Sandiford

This week

  • Worked on a fix for Submitted the patch upstream.

  • Finished first cut of vldN and vstN vectorisation. Send the patches upstream. Most of the patches have been approved, but I'll wait for the others before committing.
  • Looked at how the vectoriser handles natty's libav. Found some nice loops, some OK-but-could-do-better, and some really atrocious. Wrote up the results here:

  • Started writing micro benchmarks for each loop on that page I'm about half way through now (starting from the bottom).
  • Started looking at whether the changes affect DENbench.
  • Patch review.
  • Wrote a small follow-up to the fix for LP 758082.
  • Some patch pinging.

Next week

  • More micro benchmarks.
  • More DENbench.
  • Submit a merge request for the intrinsics improvements, if the remaining patches are approved.
  • Look at the poorer libav loops in more detail.

Ulrich Weigand

WorkingGroups/ToolChain/ActivityReports/2011-04-15 (last modified 2011-04-19 20:00:40)