linaro-toolchain

linaro-toolchain@lists.linaro.org

3 participants
5657 discussions

by William Mills

We are using the Linaro prebuilt binary 2013.03 toolchain. We have a program that does a memcpy of 6 bytes and the source and destination pointers are both 6 byte arrays (through multiple levels of struct & union etc). At -O2 we get the memcpy inlined. The code area in question is: 22840: f8b7 2054 ldrh.w r2, [r7, #84] ; 0x54 22844: f853 1d12 ldr.w r1, [r3, #-18]! 22848: f042 0202 orr.w r2, r2, #2 2284c: 889b ldrh r3, [r3, #4] 2284e: b292 uxth r2, r2 ->22850: f8c7 101a str.w r1, [r7, #26] 22854: f8a7 2054 strh.w r2, [r7, #84] ; 0x54 22858: 83fb strh r3, [r7, #30] 2285a: f8da 3000 ldr.w r3, [sl] And we get an alignment fault at the str.w marked above. Looking at the types involved and their location in the containing structures I don't see how the compiler could think that the destination was word aligned (I believe it is guaranteed that dest % 8 == 6) There are no -march -mcpu or -mtune params passed to the compiler. The code is running in user space on a A15. Basic question before we look further: Is the compiler assuming that cp15 SCTLR.A is 0 so that it is free to generate unaligned loads and stores? If the answer to the above is "no" we can isolate the code more and bring it back to the list. Thanks, Bill --------------------------------------- William A. Mills Chief Technologist, Open Solutions, SDO Texas Instruments, Inc. 20450 Century Blvd Germantown MD 20878 240-643-0836

12 years, 5 months

[ANNOUNCE] Linaro Toolchain binaries 2013.05 released

by Bernhard Rosenkränzer

The Linaro Toolchain and Platform Working Groups are pleased to announce the 2013.05 release of the Linaro Toolchain Binaries, a pre-built version of Linaro GCC and Linaro GDB that runs on generic Linux or Windows and targets the glibc Linaro Evaluation Build. Uses include: * Cross compiling ARM applications from your laptop * Remote debugging * Build the Linux kernel for your board What's included: * Linaro GCC 4.8 2013.05 * Linaro GDB 7.6 2013.05 * A statically linked gdbserver * A system root * Manuals under share/doc/ The system root contains the basic header files and libraries to link your programs against. Interesting changes include: * gcc 4.7 is no longer included * gdb is updated to 7.6 * Linux release file names no longer include a date to make life easier for scripted downloads * ISL/CLooG support is enabled in all builds The Linux version is supported on Ubuntu 10.04.3 and 12.04, Debian 6.0.2, Fedora 16, openSUSE 12.1, Red Hat Enterprise Linux Workstation 5.7 and later, and should run on any Linux Standard Base 3.0 compatible distribution. Please see the README about running on x86_64 hosts. The Windows version is supported on Windows XP Pro SP3, Windows Vista Business SP2, and Windows 7 Pro SP1. The binaries and build scripts are available from: https://launchpad.net/linaro-toolchain-binaries/trunk/2013.05 Need help? Ask a question on https://ask.linaro.org/ Already on Launchpad? Submit a bug at https://bugs.launchpad.net/linaro-toolchain-binaries On IRC? See us on #linaro on Freenode. Other ways that you can contact us or get involved are listed at https://wiki.linaro.org/GettingInvolved.

12 years, 5 months

Linaro-toolchain-builds rebuilding sysroot

by BHARATH H S

Hi, I have a usecase where linaro toolchain is used to build my executables and the sysroot is copied and used as glibc for running my embedded system. Reason for this is, I want to use the same glibc what the application is compiled against. I found a bug fix from glibc community which I want to cherry pick and rebuild the sysroot to include this fix. But, in the README.txt published with linaro toolchain binary, there are no instructions for rebuilding sysroot. Can anyone point me to info on rebuilding sysroot? If formal steps don't exist, could you point me to the current process being followed by linaro so that I can observe the build log and attempt to do the same? Thanks Bharath

12 years, 5 months

Malloc usage

by Matthew Gretton-Dann

All, In the Toolchain Working Group Mans has been doing some examination of SPEC 2000 and SPEC 2006 to see what C Library (glibc) routines impact performance the most, and are worth tuning. This has come up with two areas we consider worthy of further investigation: 1) malloc performance 2) Floating-point rounding functions. This email is interested with the first of these. Analysis of malloc shows large amounts of time is spent in executing synchronization primitives even when the program under test is single-threaded. The obvious 'fix' is to remove the synchronization primitives which will give a performance boost. This is, of course, not safe and will require reworking malloc's algorithms to be (substantially) synchronization free. A quick Google suggests that there are better performing algorithms available (TCMalloc, Lockless, Hoard, &c), and so changing glibc's algorithm is something well worth investigating. Currently we see around 4.37% of time being spent in libc for the whole of SPEC CPU 2006. Around 75% of that is in malloc related functions (so about 3.1% of the total). One benchmark however spends around 20% of its time in malloc. So overall we are looking at maybe 1% improvement in the SPEC 2006 score, which is not large given the amount of effort I estimate this is going to require (as we have to convince the community we have made everyone's life better). So before we go any further I would like to see what the view of LEG is about a better malloc. My questions boil down to: * Is malloc important - or do server applications just implement their own? * Do you have any benchmarks that stress malloc and would provide us with some more data points? But any and all comments on the subject are welcome. Thanks, Matt -- Matthew Gretton-Dann Toolchain Working Group, Linaro

12 years, 5 months

Debuggin from Eclipse

by Paul Claessen

Greetings, I'm using the Linaro tool chain with Eclipse (Juno) (under Windows) and openOCD to write firmware for an STM32F20x based design (using an ST-Link2 debugger). In general, that all works fairly well. The part I'm having problems with is debugging (step-in, etc) from Eclipse. The execution flow seems chaotic when single stepping through C code: it skips statements, it jumps into the middle of a function, then returns to the start of a function, it loops over certain statements (while there's no loop in the code), etc. (It's close to useless). I have seen this behavior with other IDE's and tool chains when code was built with optimization turned on. However, I specify 'no optimization' (-O0) when I build my code. My questions: a) Is there some implicit optimization being done in the compiler, even though I tell it not to do so, which may affect proper debugging? b) Are other people using Eclipse (Juno) and are they seeing the same issue? Are there any known ways to fix this chaotic debugger behavior? Kind regards, ~ Paul Claessen

12 years, 5 months

[ACTIVITY] 21 - 24 May 2013

by Omair Javaid

== Progress == * Performed investigation on gdb7.6 test suite failures and untested test cases. * Updated JIRA enteries with test suite failures on arm to track progress. * Wrote an automation script for selection of individual test cases from a text file. * Got the gdb.dwarf2 test suite patch reviewed from Matt and Will. * Day off on Friday. == Plan == * Finish up initial investigation on gdb7.6 test suite results. * Complete updates of JIRA enteries after investigation on test suite results in complete. * Start work on integration of different testing scripts written in past couple of months. * Send gdb.dwarf2 test suite patch upstream.

12 years, 5 months

How to represent conditional compare in RTL?

by Zhenqiang Chen

Hi Richard, After adding some new ops, I can keep the conditional compare to the end of tree-level optimization. As tests, I expand conditional compare to BIT_AND_EXPR/BIT_IOR_EXPR, which still depend on later "combine" pass to combine them. Is it possible to expand it to *cmp_and/*cmp_ior like patterns? What's the expected RTL representation for conditional compare after expand and before combine? Thanks! -Zhenqiang

12 years, 5 months

[ACTIVITY] 21-24 May 2013

by Venkataramanan Kumar

== Progress == 4 day week was ill on Friday. * AARCH64 gprof –c option support. Completed and submitted patch in binutils and got it upstreamed. http://sourceware.org/ml/binutils/2013-05/msg00265.html http://sourceware.org/ml/binutils/2013-05/msg00264.html The committer has changed the logic and seems it is not working for backward addresses. Sent him an offline mail to correct it. http://sourceware.org/ml/binutils/2013-05/msg00279.html * AARCH64 gprof –glibc support. Submitted patch and got is approved http://sourceware.org/ml/libc-ports/2013-05/msg00098.html * AARCH64 gprof – gcc support Tested with removing test clause as suggested by Marcus (Aarch64 maintainer). Marcus wants me to send two separate patches. Will be posting it. * AARCH64 testing Got boot strap failure with GCC 4.9 trunk on open embedded image with glibc changes. To confirm it is not a regression I ran with the openembedded image available at Linaro download site. Bootstrap failure can be reproduced. I am documenting the steps to increase the size of image and also Steps to reproduce boot strap failure in the model. == Plan == * Continue bootstrap testing and push patches to GCC * libssp support for Aarch64 * Linaro connect travel prep. Misc ------ Planned leave 29-5-2013.

12 years, 5 months

[ACTIVITY] Week 21

by Yvan Roux

== Issues == * None. == Progress == * LRA on ARM and AArch64: - Reduced the ARM test case. - The issue occurs during the constraints alternatives choice. - Debug still ongoing. == Plan == * LRA, LRA and LRA

12 years, 5 months

[ACTIVITY] Week 21

by Zhenqiang Chen

== Issues == * None == Progress == * Run native regression tests for conditional compare on Pandaborad ES. - Fix several front-end issue to handle conditional compare in error message. == Plan == * Continue on conditional compare. * Linaro toolchain 2013.05 binary release. Best Regards! -Zhenqiang

12 years, 5 months

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