linaro-toolchain November 2014

linaro-toolchain@lists.linaro.org

24 participants
47 discussions

New IRC Channel for Linaro Toolchain Working Group

by Matthew Gretton-Dann

All, During Connect the suggestion was made that each working group should have its own IRC Channel for discussions and topics relating to the group in particular (as opposed to #linaro which is 'generic' Linaro conversations). Therefore I have just set up #linaro-tcwg on Freenode for the Toolchain Working Group. This channel is public and open to anyone who wants to talk with the TCWG group about anything toolchain related. Thanks, Matt -- Matthew Gretton-Dann Toolchain Working Group, Linaro

3 years, 5 months

renaming completed

by Rob Savoye

I've completed renaming Cbuildv2 to Abe, as well as modifying all the board files for remote testing to match what the new DNS server is using. Please stop using the existing cbuild2 repository, as all changes are now done in the new repository. I'll leave the old repository for a while, I know there are branches there people depend on. For those, I'm sorry for the pain (having just gone through that myself), but please migrate any important branches to the new repository. URLs for that are here: https://git.linaro.org/toolchain/abe.git - rob -

10 years

Latest Toolchain Binaries

by Christopher Covington

Hi, The latest toolchain on the following page appears to be broken. http://www.linaro.org/projects/armv8/ Looking around one comes across the following path. http://releases.linaro.org/latest/components/toolchain/.binaries However the tarballs there yield: "You do not have permission to access this file." Thanks, Chris -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project

10 years

[ACTIVITY] 24-28 November 2014

by Christophe Lyon

== Progress == * GCC trunk/4.9 cross-validation (1/10) - monitoring - tracking cause of spurious "interrupted system call" - testing small changes in harness * AArch64 sanitizers (2/10) - resumed discussion with Maxim/Arnd, the situation is clearer now - started looking at running asan tests in llvm environment (Thanks Renato) * Linaro GCC releases (2/10) - 2014.12 backports reviews - improved scripts to help speed up reviews * Neon intrinsics tests (2/10) - continuing to convert the existing testsuite to dejagnu - checking ARM's aarch64_be patches * Misc (3/10) - calls, meetings, ... == Next == * Neon intrinsics * AArch64 sanitizers * cbuild2 (improve backport-test and tcwgweb)

10 years

[ACTIVITY] Week 48

by Renato Golin

== Progress == * 2 days sick * Lab move (2/6) * Buildbots (TCWG-76 2/6) - Created a buildmaster at Linaro to help local development - Put a dragonboard as a slave, which lasted 2 days up * Background (2/6) - Code review, meetings, discussions, etc. == Plan == * I have no idea

10 years

[ACTIVITY] 24 - 28 November 2014

by Will Newton

== Progress == * Building an ILP32 toolchain for AArch64 (3/10, TCWG-559) - More work on tidying patches - Trying to get a test environment for ILP32 * LLD for ARM and AArch64 (5/10) - Submit more reloc cleanups for LLVM - Patch review - Reading code * glibc patch review (1/10, CARD-341) * Email, meetings, etc. (1/10) == Issues == * OE on Junos no good for building toolchains * Ubuntu on Junos still seems vaporware * Running out of disk space on development machine (bought an external HD) == Plan == * More work on LLD * Try QEMU for ILP32 work -- Will Newton Toolchain Working Group, Linaro

10 years

[ACTIVITY] 24th - 28th November

by Bernie Ogden

ABE benchmarking - TCWG-360 [4/10] * Implemented most of a solution to the 'must be in same network' restriction libm exercising - TCWG-558 [4/10] * lulesh generates needless calls to pow on AArch64 (as opposed to 'pow is slow') ** Working on a reduced test case * Ran a chunk of benchfft, left a process searching the perf reports for libm calls * More chroot/glibc fiddling * Decided Graph500 was unlikely to be interesting Misc - [2/10] =Plan= On holiday Monday - Wednesday More lulesh, benchfft results Think about where to go next with libm exercising Complete 'same network' workaround, test benchmark repeatability Port benchmarking scripts to ABE repo Get storage/automation started, if Rob has time

10 years

building eglibc for arm-linux-gnueabihf tools with multilib support

by Mallikarjun.Gouda＠freescale.com

Hi All, Currently linaro toolchain for arm-linux-gnueabihf built with crosstool-ng scripts uses prebuilt sysroot. I am trying to build eglibc on my own without using prebuilt sysroot. I am not able to exactly create same layout in the library layout. Linaro build layout looks: gcc-linaro-arm-linux-gnueabihf-4.8-2014.01_linux\arm-linux-gnueabihf\libc\usr\lib --> arm-linux-gnueabi arm-linux-gnueabihf one for soft float and other for hard float fp. Can anybody please tell how we tell build system to create directories like above while building eglibc? I used following commands to build eglibc: ../src_eglibc/configure --disable-profile --without-gd --without-cvs --prefix=/usr libc_cv_forced_unwind=yes libc_cv_c_cleanup=yes --with-headers=<some_dir>/arm-linux-gnueabihf/libc/usr/include --host=arm-linux-gnueabihf Make all make install install_root= <some_dir>/arm-linux-gnueabihf/libc/ Thank you very much for your help. //Mallikarjuna

10 years, 1 month

Fw: strange behavior in GCC for use of uninitialized variables

by Pinski, Andrew

Forwarding this message to the linaro toolchain list instead. I am not the person who should be supporting the Linaro ODP project with GCC questiosn; the toolchain team inside Linaro should be instead. Thanks, Andrew Pinski ________________________________________ From: Ola Liljedahl <ola.liljedahl(a)linaro.org> Sent: Monday, November 24, 2014 2:31 PM To: lng-odp(a)lists.linaro.org; Pinski, Andrew Subject: strange behavior in GCC for use of uninitialized variables Consider the following code fragment (from real life): #include <stdint.h> typedef volatile uint32_t odp_atomic_u32_t; static inline uint32_t odp_atomic_fetch_inc_u32(odp_atomic_u32_t *ptr) { return __sync_fetch_and_add(ptr, 1); } static inline void odp_spin(void) { #ifdef __SSE2__ __asm__ __volatile__ ("pause"); #else __asm__ __volatile__ ("rep; nop"); #endif } typedef struct { int count; odp_atomic_u32_t bar; } odp_barrier_t; void odp_barrier_wait(odp_barrier_t *barrier) { uint32_t count; int wasless; // wasless = barrier->bar < barrier->count; <<<lost on git add -p __atomic_thread_fence(__ATOMIC_SEQ_CST); count = odp_atomic_fetch_inc_u32(&barrier->bar); if (count == 2*barrier->count-1) { barrier->bar = 0; } else { while ((barrier->bar < barrier->count) == wasless) odp_spin(); } __atomic_thread_fence(__ATOMIC_SEQ_CST); } While fixing and cleaning up this code, the indicated line that initializes 'wasless' was dropped (because it reappears in a later patch in the patch set after the odp_atomic_fetch_inc call). To my surprise, GCC did not complain when compiling this file (using -O2 -Wall). But it does complain when compiling with -O0 -Wall. With some investigation, it seems like GCC understands that if a statement does not have any side effects so it can optimize away everything, including the usage of the uninitialized variable and thus also the corresponding warning. olli@macmini:~/hacking/gcc-wunit$ gcc -O2 -Wall -c odp_barrier.c olli@macmini:~/hacking/gcc-wunit$ gcc -O0 -Wall -c odp_barrier.c odp_barrier.c: In function ‘odp_barrier_wait’: odp_barrier.c:42:9: warning: ‘wasless’ may be used uninitialized in this function [-Wmaybe-uninitialized] while ((barrier->bar < barrier->count) == wasless) ^ However the proper code seems to be generated in both cases (there is a "pause" instruction inlined or a call to odp_spin). So odp_spin() is not without side effects and is not optimized away. This contradicts my hypothesis. Consider this minimalistic example: olli@macmini:~/hacking/gcc-wunit$ cat wunit.c #include <stdlib.h> void test(void) { int wasless; int wasmore; if (wasless) (void)0; if (wasmore) abort(); } olli@macmini:~/hacking/gcc-wunit$ gcc -O0 -Wall -c wunit.c wunit.c: In function ‘test’: wunit.c:9:5: warning: ‘wasmore’ is used uninitialized in this function [-Wuninitialized] if (wasmore) abort(); ^ olli@macmini:~/hacking/gcc-wunit$ gcc -O2 -Wall -c wunit.c wunit.c: In function ‘test’: wunit.c:9:5: warning: ‘wasmore’ is used uninitialized in this function [-Wuninitialized] if (wasmore) abort(); ^ Here GCC warns when used with both -O0 and -O2 but only for the usage where there is a side effect. The use of 'wasless' that does not lead to any side-effects is ignored (and possibly rightly so, I can imagine this is undefined behavior, fortunately I did not attempt to run this program or my computer could have melted). It is a bit worrying to me that instances of use of initialized variables is sometimes missed by GCC. Both because of lack of diagnostics for what is most likely a bug but also because I don't understand why GCC does this and the implications of that (at least it is a known unknown now). -- Ola

10 years, 1 month

[ACTIVITY] 17th - 21st November

by Bernie Ogden

cbuild2/ABE benchmarking - TCWG-360 [1/10] * Attempted to use LAVA for benchmarks ** Fell over on lack of TCWG machines in same network libm exercising - TCWG-558 [6/10] * Much fiddling with chroots * Some fiddling with benchfft * Little actual progress Meetings/mail/etc - [3/10] =Plan= libm exercising * Run benchfft in chroots * Investigate Graph500 * Validate existing results with consistent methodology ** Hopefully this is reaching the point of handle-turning ABE benchmarking * Port 'cbuild2' benchmarking to ABE repository * Test ABE benchmarking in TCWG lab (and LAVA?) * Test repeatability (assuming the above go well) * Get storage/automation started, if Rob has time Holiday *next* week (Tuesday and Wednesday, perhaps Monday as well)

10 years, 1 month

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linaro-toolchain November 2014