Hello toolchain gurus,
In the course of Linaro's kernel tinification project, the ability to
compile the Linux kernel using LTO is a frequent requirement. However
the kernel makes heavy usage of 'ld -r' with .o files resulting from LTO
build of .c files as well as .o files resulting from pure assembly code.
This mix of LTO and non-LTO object files is not supported by upstream
binutils unless a patch from H.J. Lu is applied. That patch has been
available since 2013 and was last refreshed in his 2.25.51.0.4 branch
last September. It is accessible here:
https://git.linaro.org/toolchain/binutils-gdb.git/commit/6da5456971
I've attached a very simple test case demonstrating the problem. With
the binutils-lto-mixed.patch applied, this test case compiles to a
working executable. Otherwise compilation fails at the 'ld -r' step.
One question and one request:
- What, if anything, has prevented this patch from being merged in the
master branch upstream?
- In the mean time, could we include this patch in the Linaro binutils
package and releases?
Having this available in our toolchain releases would greatly simplify
the LTO related work on the kernel. It was included in all binutils
releases from H.J. Lu since 2013 and therefore has obtained significant
exposure already.
Thanks.
Nicolas
== This Week ==
* TCWG-72 (2/10)
- Trying to address segfault with DImode
* LTO ICE with 483.xalancbmk (6/10)
- fighting with benchmark scripts
- segfaults with ICE on -flto-partitions=none
on symbol _ZThn8_N10xalanc_1_819XercesParserLiaison11resetErrorsEv
demangler.com says the symbol is non-virtual thunk to:
non-virtual thunk to xalanc_1_8::XercesParserLiaison::resetErrors()
./-lm.res (resolution map file) says PREVAILING_DEF_IRONLY
- Trace: http://pastebin.com/vxzmQFHg
- Possible fix: http://pastebin.com/rwq8z1N1
Patch passes test and bootstrap, not sure if that's correct approach however.
* Target hook conversion (2/10)
- Unconditionalizing ASM_OUTPUT_DEF on SET_ASM_OP and converting
both to hooks.
NB Last _6_ working days.
Centralised benchmark source - TCWG-354 [6/10]
* Abe integration
* Wrote up some notes on collaborate
* Enabled clang build, which flushed out some bugs, now fixed
* LAVA reporting script
Port to microinstance - TCWG-432 [1/10]
* Investigating issues with Juno boot
** One turns out to be user error
** The other is a failed heath check, passed to the admins
Backport benchmarking - TCWG-352 [2/10]
* Difficulties with passing information from matrix children to parent
** Came up with an ugly workaround, may have thought of a better one
Misc [3/10]
=Plan=
Holidays until 4th January
# Progress #
* TCWG-156, GDB Test-Suite Parity Between Aarch64 and x86_64. Done. [4/10]
After two patches are committed, except some tests written for x86_64
unnecessarily, the test results between aarch64 and x86_64 looks no
difference.
* TCWG-424, timeout when interrupt the inferior in remote debugging. [3/10]
The fail is caused by different two problems. Two patches are ready,
and being regression tested.
* TCWG-171, Enable gdb core file tests when testing remotely. [1/10]
Write down my conclusion as it can't be fixed.
* Upstream review, [2/10]
** Review patch about handling ada aarch64 HVA array in GDB.
** Discuss target description of GDB for cortex-m device with openocd.
# Plan #
* Post patches upstream for TCWG-424,
* Patches review.
* On holiday since Wed.
--
Yao
Hi All,
I am interested in understanding Linaro LLVM activity.
I have already gone through
https://wiki.linaro.org/WorkingGroups/ToolChain/LLVM.
Could you please guide me on below questions.
1. On which LLVM & clang version, linaro is actively working now ?
2. Where can I find the latest "linaro-llvm" source code & binary? I could
not find any official git repo for "linaro-llvm" at https://git.linaro.org/.
3. Could you please explain Linaro LLVM working model? How
similar/different it is when compared with Linaro-GCC engagement.
4. Certain links (e.g Roadmap) at
https://wiki.linaro.org/WorkingGroups/ToolChain/LLVM ask for login
credentials. Any comment on how to obtain the permission?
Thanks in advance for your time.
--
with regards,
Virendra Kumar Pathak
* 1 day off (Friday) (2/10)
== Progress ==
* Validation: (2/10)
- improvements to the comparison scripts
- updated ABE stable and staging branches
* GCC: (3/10)
- TCWG-484: sent a new version of the patch to address problems with
the testsuite and target attributes.
- TCWG-485/PR68620: WIP, trying to understand the regressions
introduced by my patch
* Misc (conf calls, meetings, emails, ...) (3/10)
== Next ==
Holidays until next year
Hi All,
As per release notes, linaro_binutils-2_25-2015_01-2_release should be
present at http://git.linaro.org/toolchain/binutils-gdb.git.
But I am not able to see any "linaro_binutils" tags on
https://git.linaro.org/toolchain/binutils-gdb.git/tags.
Am I doing any mistake? or on git it is renamed to something else (same as
FSF binutils tags?).
Apology for asking such a trivial question.
Thanks for your time.
--
with regards,
Virendra Kumar Pathak
The Linaro Toolchain Working Group (TCWG) is pleased to announce the
2015.12 snapshot of the Linaro GCC 5 source package.
This monthly snapshot[1] is based on FSF GCC 5.3+svn231642 and
includes performance improvements and bug fixes backported from
mainline GCC. This snapshot contents will be part of the 2015.11
stable [1] quarterly release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/5.3-2015.12/
Interesting changes in this GCC source package snapshot include:
* Updates to GCC 5.3+svn231642
* Backport of [Bugfix] [AArch32] 1/4 PR63870 Add qualifiers for NEON builtins
* Backport of [Bugfix] [AArch32] 2/4 PR63870 Mark lane indices of
vldN/vstN with appropriate qualifier
* Backport of [Bugfix] [AArch32] 3/4 PR63870 Remove error for invalid
lane numbers
* Backport of [Bugfix] [AArch32] 4/4 PR63870 Remove xfails for ARM targets
* Backport of [Bugfix] [AArch32] PR67305, tighten
neon_vector_mem_operand on eliminable registers
* Backport of [Bugfix] [AArch32] remove unused variable
* Backport of [Bugfix] [AArch64] PR 63304 Fix issue with global state
* Backport of [Bugfix] [AArch64] PR63304 Handle literal pools for
functions > 1 MiB in size
* Backport of [Bugfix] [AArch64] PR 68088: Fix RTL checking ICE due to
subregs inside accumulator forwarding check
* Backport of [Bugfix] [AArch64] PR rtl-optimization/67218
* Backport of [Bugfix] PR 56036 fix typo in doc
* Backport of [Bugfix] PR rtl-optimization/68236: Exit early from
autoprefetcher lookahead if not in haifa sched
* Backport of [Bugfix] PR tree-optimization/68234 Improve range info
for loop Phi node
* Backport of [AArch32] 1/4 Change GET_MODE_INNER to always return a
non-void mode
* Backport of [AArch32] 2/3 Make if_neg_move and if_move_neg into insn_and_split
* Backport of [AArch32] 2/4 Control the FMA steering pass in tuning
structures rather than as core property
* Backport of [AArch32] 3/3 Expand mod by power of 2
* Backport of [AArch32] 3/4 Replace the pattern GET_MODE_BITSIZE
(GET_MODE_INNER (m)) with GET_MODE_UNIT_BITSIZE (m)
* Backport of [AArch32] 4/4 Fix - Introduce new inline functions for
GET_MODE_UNIT_SIZE and GET_MODE_UNIT_PRECISION
* Backport of [AArch32] 4/4 Introduce new inline functions for
GET_MODE_UNIT_SIZE and GET_MODE_UNIT_PRECISION
* Backport of [AArch32/AArch64] 2/2 Add a new Cortex-A53 scheduling model
* Backport of [AArch32] Add missing v8a cpus to the t-aprofile file
* Backport of [AArch32] Fix checking RTL error in cortex_a9_sched_adjust_cost
* Backport of [AArch32] Fix for testcase after r228661
* Backport of [AArch32] Initialise cost to COSTS_N_INSNS (1) and
increment in arm rtx costs
* Backport of [AArch32] libgcc: include crtfastmath
* Backport of [AArch32] Unified assembler in ARM state
* Backport of [AArch64] 1/2 Give AArch64 ROR (Immediate) a new type attribute
* Backport of [AArch64] 1/2 Rename SYMBOL_SMALL_GOT to SYMBOL_SMALL_GOT_4G
* Backport of [AArch64] 1/2 Rename test source file for reuse
* Backport of [AArch64] 1/3 Add the option -mtls-size
* Backport of [AArch64] 1/3 Expand signed mod by power of 2 using CSNEG
* Backport of [AArch64] 2/2 Implement -fpic for -mcmodel=small
* Backport of [AArch64] 2/2 Implement TLS IE for tiny model
* Backport of [AArch64] 2/3 Rename SYMBOL_TLSLE to SYMBOL_TLSLE24
* Backport of [AArch64] 3/3 Implement local executable mode for all memory model
* Backport of [AArch64] Add initial qualcomm support
* Backport of [AArch64] Add missing entries in iterator vwcore
* Backport of [AArch64] Cleanup whitespace in aarch64.c
* Backport of [AArch64] Cortex-A57 Choose some new branch costs
* Backport of [AArch64] Define TARGET_UNSPEC_MAY_TRAP_P
* Backport of [AArch64] Distinct costs for sign and zero extension
* Backport of [AArch64] Do not ICE after apologising for -mcmodel=large -fPIC
* Backport of [AArch64] Don't allow -mgeneral-regs-only to change the
.arch assembler directives
* Backport of [AArch64] Don't transform sign and zero extends inside mults
* Backport of [AArch64] Fall back to -fPIC if no support of -fpic in binutils
* Backport of [AArch64] Fix for branch offsets over 1 MiB
* Backport of [AArch64] Fix ICE on (const_double:HF 0.0)
* Backport of [AArch64] Fix insn types
* Backport of [AArch64] Fix output assembly bug under TLSIE ILP32
* Backport of [AArch64] Handle vector float modes properly in
aarch64_output_simd_mov_immediate
* Backport of [AArch64] Mark GOT related MEM rtx as const to help RTL loop IV
* Backport of [AArch64] Properly handle simple arith+extend ops in rtx costs
* Backport of [AArch64] Rename SYMBOL_SMALL_GOTTPREL to SYMBOL_SMALL_TLSIE
* Backport of [AArch64] Restrict pic-small.c by new test directive
* Backport of [AArch64] Tighten direct call pattern for sibcall to
repair -fno-plt
* Backport of [AArch64] Tighten direct call pattern to repair -fno-plt
* Backport of [Testsuite] [AArch32] Fix thumb2-slow-flash-data.c failures
* Backport of [Testsuite] [AArch32] Switch ARM to unified asm
* Backport of [Testsuite] [AArch64] Add more TLS local executable testcases
* Backport of [Testsuite] [AArch64] Check branch types for noplt testcases
* Backport of [Testsuite] [AArch64] Fix gcc.target/aarch64/vclz.c
* Backport of [Testsuite] [AArch64] Fix some target attribute inlining
tests for -fPIC
* Backport of [Testsuite] [AArch64] Restrict got_mem_hoist_1.c with
small memory model
* Backport of [Testsuite] [AArch64] Skip tiny and large code model on
gcc.target/aarch64/pic-small.c
* Backport of [Testsuite] Add --param
sra-max-scalarization-size-Ospeed to sra-12.c
* Backport of [Testsuite] Fix target selector in
gcc.target/i386/noplt-[1234].c testcases
* Backport of [Misc] Allow sibcalls in no-PLT PIC
* Backport of [Misc] Eliminate PLT stubs for specified external
functions via -fno-plt
* Backport of [Misc] Fix for ICE with -g on testcase with incomplete types
* Backport of [Misc] Fix memory leak and wrong invariant dependence
computation in IVOPT
* Backport of [Misc] Improve rtl loop inv cost by checking if the inv
can be propagated to address uses
* Backport of [Cleanup] [AArch32/AArch64] fix ChangeLog
* Backport of [cleanup] [AArch32] Remove uses of CONST_DOUBLE_HIGH/LOW
* Backport of [Cleanup] [AArch64] Delete aarch64_symbol_context which
is not used
* Backport of [cleanup] [AArch64] Move iterators from atomics.md to iterators.md
* Backport of [cleanup] [AArch64] Remove uses of CONST_DOUBLE_HIGH,
CONST_DOUBLE_LOW
* Backport of [Doc] [AArch64] Document several AArch64-specific test directives
Feedback and Support
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[1]. Stable source package releases are defined as releases where the
full Linaro Toolchain validation plan is executed.
[2]. Source package snapshots are defined when the compiler is only
put through unit-testing and full validation is not performed.
