== Progress ==
* ARM Process Record:
- Follow up on patches, almost all patches accepted. [0.5/10]
- Got GDB committ rights and set up git for pushing patches. [0.5/10]
* Spent time to read through fortran functions prologue to find a new fix
for TCWG-267. [1/10]
* Initial investigation of handling breakpoint over fork [TCWG-177] [1/10]
* Getting documentation ready for Macau visa application [2/10]
== Plan ==
* Update and send patches where required and committ all approved patches.
* Work on breakpoints issues [TCWG-177] and reverse stepping through solib
issue [TCWG-315]
* Apply for Macau visa, given all documents get ready.
== Progress ==
* Libc probes support for Aarch64.
Posted patch for "libc" probes support to "__longjump". Worked on
review comments from Maintainers. Upstream discussions in progress.
Working on testing "glibc" by using --enable-systemtap.
* Experimented with "Cbuildv2" native building.
== Plan ==
- Continue Cbuildv2.
- Investigate "PGO" for Aarch64.
- Work on "glibc" probe.
== Issues ==
Waiting for feedback on "libssp" machine descriptions changes.
misc
===
14-Jan-2014 leave.
== Progress ==
* Draft wiki page (under ACL--let me know if you want to see) for
instructions for setting up chroots on chromebooks for glibc testing:
https://collaborate.linaro.org/display/~ryan.arnold@linaro.org/Configuring+…
* Investigated expanding remote testing possibilities in glibc.
* RFC email to libc-alpha discussing proposal for glibc host testsuite
in chroots:
https://sourceware.org/ml/libc-alpha/2014-01/msg00222.html
== Issues ==
* Shortened week (3-days) because of unplanned school closures on
Monday and Tuesday due to freezing temperatures, during which I had to
watch my kids.
== Plan ==
* Start code scaffolding for glibc host testsuite in chroot.
* Start cbuild2 scaffolding for building remote chroots for glibc testing.
* Add glibc multi-lib builds and IFUNC system libraries.
* Work on cbuild2 support for local tar files.
== Progress ==
* Two day week
* Catching up on email etc. after break (0.5/10)
* Investigate setjmp/longjmp SystemTap probe support in ARM glibc
(1/10, TCWG-378)
* Investigate toolchain bug reports for ARM and AArch64 (0.5/10)
== Issues ==
* None
== Plan ==
* Resume QEMU ARMv8 AArch32 work
* Hopefully push glibc ARM pointer encryption fix for 2.19
--
Will Newton
Toolchain Working Group, Linaro
- 2013.12 releases (1/10)
* Sent announcements for 4.7 and 4.8 releases.
- 2014.01 releases (2/10)
* Created 4.7 and 4.8 branch merge requests (had handle some conflicts in 4.8)
* Looked at backporting the crypto intrinsics support into 4.8, but
there are dependencies with several other patches we haven't
backported yet.
- cross validation (4/10)
* Restarted them since I had to stop them during the holidays. Still
catching up with the backlog, should be OK during the week-end.
* Analyzed and reported several regressions or new tests failing in
some configurations.
- Neon intrinsics tests (1/10)
* Looked at Rob's neon-intrinsics branch and sent him some feedback.
- misc (2/10): conf-calls and meetings.
== Next ==
- 2014.01 releases
- cross-validation: look at results and report regressions if any
- resume libsanitizer work for AArch64
== Progress ==
* Release 3.4 went out
* Buildbots
- Using powered USB hub for the external harddrive, but all boards fail
one time or another...
- Maybe it's the hard-drive type (mobile, power-saving), reverting to USB
sticks for now
- Leaving an odroid U2 running on USB stick for a week, used to work...
- C++11 features will need GCC 4.7+, looking for an easy way to upgrade
the Chromebooks
* MCJIT
- Finished work on remote MCJIT to re-enable the failing tests
- http://llvm-reviews.chandlerc.com/D2527
* Pragma Vectorize
- New discussions hint that my parser patch is moot, for now
- Agreement is to use C++11 attributes for now, and add pragmas later
- I can't continue implementing them, though...
* Background
- Huge number of patch reviews during holidays & this week
- Good progress on new features for the IAS
- More progress on EHABI, including IAS support
* Time
- CARD-862 8/10
- Others 2/10
== Plan ==
* Continue reviewing IAS features, maybe implement some
* Work out how to create a libcxx bot
* re-introduce llvm-chrome-01 as second self-host
* Migrate all buildbots to GCC 4.7+
* Check out EHABI tests and assess progress
Hi,
I filed this on bugzilla:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59744 but I thought I'd
mention it here too.
This slightly strangely written program (it's distilled down from
frame_offset_overflow in the gcc source itself) should print "bigger" if
the first argument is bigger than 10 (or negative, but let's ignore that
please):
#include <stdlib.h>
#include <stdio.h>
int a[2] = { 10, 20 };
int
is_bigger (long offset, int index)
{
unsigned long size = -offset;
if (size > a[index])
{
printf("bigger\n");
return 1;
}
return 0;
}
int
main (int argc, char** argv)
{
long v;
v = atol(argv[1]);
is_bigger(-v, 0);
return 0;
}
When compiled at -O1 or above (and with inlining disabled at -O2 and
above), though, it bungles the 0 case:
(t-doko)mwhudson@arm64:~$ gcc-4.9 -O3 test.c -o test -fno-inline -Wall
(t-doko)mwhudson@arm64:~$ ./test 1
(t-doko)mwhudson@arm64:~$ ./test 11
bigger
(t-doko)mwhudson@arm64:~$ ./test 0
bigger
(t-doko)mwhudson@arm64:~$ gcc-4.9 -O0 test.c -o test -Wall
(t-doko)mwhudson@arm64:~$ ./test 1
(t-doko)mwhudson@arm64:~$ ./test 11
bigger
(t-doko)mwhudson@arm64:~$ ./test 0
(t-doko)mwhudson@arm64:~$
What's going on? Here's the disassembly of is_bigger (at O3):
0000000000400608 <is_bigger>:
400608: b0000082 adrp x2, 411000 <_GLOBAL_OFFSET_TABLE_+0x28>
40060c: 91010042 add x2, x2, #0x40
400610: a9bf7bfd stp x29, x30, [sp,#-16]!
400614: 52800003 mov w3, #0x0 // #0
400618: 910003fd mov x29, sp
40061c: b8a1d841 ldrsw x1, [x2,w1,sxtw #2]
400620: ab00003f cmn x1, x0
400624: 540000a2 b.cs 400638 <is_bigger+0x30>
400628: 90000000 adrp x0, 400000 <_init-0x3f8>
40062c: 911b6000 add x0, x0, #0x6d8
400630: 97ffff90 bl 400470 <puts@plt>
400634: 52800023 mov w3, #0x1 // #1
400638: 2a0303e0 mov w0, w3
40063c: a8c17bfd ldp x29, x30, [sp],#16
400640: d65f03c0 ret
Basically it seems that the condition "-offset > val" is being compiled
as "val + offset does not overflow", which is not valid for offset == 0.
This seems to me to be the underlying cause behind
https://bugs.launchpad.net/ubuntu/+source/gcc-4.8/+bug/1263806 ("gccgo
fails to compile tomb.go on arm64").
Cheers,
mwh
