* One day off after Connect
== Progress ==
o Linaro GCC/Validation
* Handover releases to ARM on-going.
o LLVM
* Continue ramp-up
o Misc
* Various meetings and discussions.
* Debrief Connect inside ST
== Plan ==
o Continue release handover
o LLVM Jira card: cleanup and find first tasks to do
== This Week ==
* TCWG-1234: code-hoisting regression (3/10)
- Have a workaround that fixes the particular regression (but may
introduce another)
- Trying to cross build benchmarks
- Investigating PRE and code-hoisting optimizations
* TCWG-1005: malloc attr propagation (3/10)
- Iteration based on upstream feedback.
* TCWG-1253 (1/10)
- Committed patch last week to add patterns for div and cmp against 0.
- Patch to transform rshift and cmp against 0 to cmp between operands
in upstream review.
* Public Holiday (2/10)
* Misc (1/10)
- Meetings
== Next Week ==
- TCWG-1234, TCWG-1005
== Connect ==
* Various discussions on GNU toolchain roadmap
== Progress ==
* GCC
- committed fix for PR71727 (strict-align bug on aarch64), backported
to gcc-7-branch
- small fixes in the testsuite
* GCC upstream validation:
- problems with internal infrastructure, but validation results OK
- reported a couple of regressions/new failures
- ran validations for a couple of tentative patches
- noise reduction: looking at how to report randomly killed processes
* misc (conf-calls, meetings, emails, ....)
- Connect feedback (internal)
== Next ==
* GCC upstream validation
* GCC/ubsan
* GCC/deprecated-IT blocks
# Progress #
* GDB SVE patches review. [4/10]
Finished my patches to remove the last use of MAX_REGISTER_SIZE. Send
them to Alan to review.
* GDB flexible target description follow-up. [4/10]
Committed some patches to improve GDB build, so that we can easily
share code of target description between GDB and GDBserver. Done.
* File Linaro Connect expense, and misc. [2/10]
# Plan #
* On holiday, Mon - Thu.
* Either GDB target description work,or ILP32 GDB branch.
--
Yao Qi
On 24 July 2017 at 18:38, Christophe Lyon <christophe.lyon(a)linaro.org> wrote:
>
>
> Le 24 juil. 2017 18:30, "Ard Biesheuvel" <ard.biesheuvel(a)linaro.org> a écrit
> :
>
> On 18 July 2017 at 13:54, Christophe Lyon <christophe.lyon(a)linaro.org>
> wrote:
>> On 13 July 2017 at 13:50, Christophe Lyon <christophe.lyon(a)linaro.org>
>> wrote:
>>> On 12 July 2017 at 19:33, Ard Biesheuvel <ard.biesheuvel(a)linaro.org>
>>> wrote:
>>>> On 12 July 2017 at 18:27, Alexei Fedorov <Alexei.Fedorov(a)arm.com> wrote:
>>>>>
>>>>> Christophe, Leif, Ard, Ryan at al.
>>>>>
>>>>>
>>>>> We are observing unaligned memory access fault with UEFI code compiled
>>>>> by
>>>>> Linaro GCC 6.3.1 & 7.1.1 using -O3 optimisation option.
>>>>>
>>>>> The fault occures at the very early stage of UEFI boot with MMU not
>>>>> being
>>>>> enabled yet.
>>>>>
>>>>> The failing function is CalculateSum8() from
>>>>> edk2\MdePkg\Library\BaseLib\CheckSum.c:
>>>>>
>>>>>
>>>>> UINT8
>>>>> EFIAPI
>>>>> CalculateSum8 (
>>>>> IN CONST UINT8 *Buffer,
>>>>> IN UINTN Length
>>>>> )
>>>>> {
>>>>> UINT8 Sum;
>>>>> UINTN Count;
>>>>>
>>>>> ASSERT (Buffer != NULL);
>>>>> ASSERT (Length <= (MAX_ADDRESS - ((UINTN) Buffer) + 1));
>>>>>
>>>>> for (Sum = 0, Count = 0; Count < Length; Count++) {
>>>>> Sum = (UINT8) (Sum + *(Buffer + Count));
>>>>> }
>>>>>
>>>>> return Sum;
>>>>> }
>>>>>
>>>>> & the instruction which causes the exception is "ldr q1, [x1], 16"
>>>>> which
>>>>> accesses Buffer = 0xE0000048 pointed by X1 register, see the part of
>>>>> generated assembly code:
>>>>>
>>>>>
>>>>> // r:\edk2\MdePkg\Library\BaseLib\CheckSum.c:49: for (Sum = 0, Count
>>>>> = 0;
>>>>> Count < Length; Count++) {
>>>>> .loc 1 49 0 is_stmt 1
>>>>> cbz x19, .L10 // Length,
>>>>> .L4:
>>>>> sub x0, x19, #1 // tmp150, Length,
>>>>> cmp x0, 14 // tmp150,
>>>>> bls .L11 //,
>>>>> // r:\edk2\MdePkg\Library\BaseLib\CheckSum.c:42: {
>>>>> .loc 1 42 0
>>>>> movi v0.4s, 0 // vect_Sum_19.24
>>>>> lsr x2, x19, 4 // bnd.18, Length,
>>>>> mov x1, x20 // ivtmp.29, Buffer
>>>>> mov x0, 0 // ivtmp.28,
>>>>> .LVL4:
>>>>> .p2align 3
>>>>> .L7:
>>>>> // r:\edk2\MdePkg\Library\BaseLib\CheckSum.c:50: Sum = (UINT8) (Sum
>>>>> +
>>>>> *(Buffer + Count));
>>>>> .loc 1 50 0 discriminator 3
>>>>> ldr q1, [x1], 16 // vect__6.23, MEM[(const UINT8
>>>>> *)vectp_Buffer.21_38]
>>>>> add x0, x0, 1 // ivtmp.28, ivtmp.28,
>>>>> cmp x0, x2 // ivtmp.28, bnd.18
>>>>> add v0.16b, v0.16b, v1.16b // vect_Sum_19.24, vect_Sum_19.24,
>>>>> vect__6.23
>>>>> bcc .L7 //,
>>>>>
>>>>> ...
>>>>>
>>>>> Although all AARCH64 code is compiled with "-mstrict-align" option
>>>>> which
>>>>> according to GCC 3.18.1 AArch64 Options:
>>>>>
>>>>> "-mstrict-align
>>>>>
>>>>> Avoid generating memory accesses that may not be aligned on a natural
>>>>> object
>>>>> boundary as described in the architecture specification."
>>>>>
>>>>>
>>>>> the generated code doesn't comply with this description. In this case
>>>>> X1 =
>>>>> Buffer @0xE0000048 and is not aligned to 16 bytes boundary.
>>>>>
>>>>> The similiar code is generated by GCC 6.3.1-2017.05 but 5.3.1-2016.05
>>>>> compiler produces only 16 bytes aligned memory accesses when loading Q1
>>>>> register.
>>>>>
>>>>>
>>>>> I attached the simple test file which can be compiled by running GCC
>>>>> compilation with
>>>>>
>>>>> -c test.c -O3 -mstrict-align -save-temps
>>>>>
>>>>> to see the difference between code generated by 7.1.1 & 5.3.1 GCC
>>>>> versions.
>>>>>
>>>>> It seems that 5.3.1 ignores "-mstrict-align" option at all and always
>>>>> generates aligned pointers for loading Q1 register, 7.1.1 & 6.3.1 also
>>>>> ignore the option but generate slighly different code with unaligned
>>>>> access
>>>>> enabled.
>>>>>
>>>>>
>>>>> Please share your thoughts regading this issue.
>>>>>
>>>>
>>>> Hello Alexei,
>>>>
>>>> This does look like a compiler bug to me. 'Buffer' is a pointer to
>>>> unsigned char, and so the compiler should never emit the ldr
>>>> instruction under -mstrict-align.
>>>>
>>>> In the mean time, we could work around this with adding
>>>> -mgeneral-regs-only in all places where -mstrict-align is being
>>>> passed. In general, I don't really see the point of supporting the use
>>>> of FP/ASIMD registers in UEFI beyond ensuring that our builds are
>>>> compatible with 3rd party binaries that do use them.
>>>>
>>>
>>> Hello Alexei,
>>>
>>> I agree with Ard: it looks like a compiler bug, I'm looking at it.
>>>
>>> And indeed in the mean time, using -mgeneral-regs-only should
>>> workaround your problem.
>>>
>>
>> Hello,
>>
>> As a follow-up, I've posted a patch:
>> https://gcc.gnu.org/ml/gcc-patches/2017-07/msg01063.html
>>
>> We'll see if maintainers agree.
>>
>
> Thanks. By the looks of it, nobody cared to respond, right?
>
>
> Not yet and we are used to slow response.
>
> In addition I'm on holidays until Aug 21st so I won't ping until then.
>
>
Hi all,
My patch was finally accepted last week and committed.
I also backported it to the gcc-7-branch, so that the problem will
be fixed in the next gcc-7 release (either FSF or Linaro).
Thanks,
Christophe
# Progress #
* Flexible GDB target description work. [5/10]
As we'll add more and more files, need to clean up GDB build first.
Patch is OK, but need to reduce the duplication first. Yet another
clean up.
Start to think about the design of removing last usage of
MAX_REGISTER_SIZE. Still ongoing.
* Misc, [5/10]
** File cauldron expense.
** Improve gdb_mbuild.sh to build GDB for different supported targets.
# Plan #
* Connect.
--
Yao Qi
== Progress ==
o Linaro GCC/Validation
* Completed backports and branch merges
* Delivered 7.2 and 6.4 monthly source snapshots
* Reviewed infra patches
* Still some patches pending on upstream reviews
o LLVM
* Still learning
o Misc
* Various meetings and discussions.
== Plan ==
o Close remaining GCC tasks
Two weeks
* GNU Cauldron and vacation, [12/20]
# Progress #
* TCWG-1159, New design of GDB/GDBserver target description. [4/20]
Commit my patches, and fix some build failures. Done.
* Cauldron presentation and Linaro Connect SFO17 presentation. [3/20]
Done.
* Misc, catch up email, [1/20]
# Plan #
* Prepare a prototype about regcache, and compare with Alan's
implementation.
* Continue my target description work, for other non-actively-maintained
target descriptions.
--
Yao Qi
== Progress ==
* Infrastructure:
- patch reviews
* Benchmarking:
- minor bug fixes
* Snapshots/releases
- branch merge reviews
* GCC upstream validation:
- PR82120: adding a -mbranch-cost option to the arm backend does not
help with pr81588.c test failing on cortex-a5
- incorrectly reported a regression due to bisect problems (worth
100% chocolate ;-)
- still working on further reducing false alams
- problems with internal infrastructure
* binutils/gdb upstream validation:
- gdbserver build fixed by Yao
* GCC
- investigating portability of ubsan to bare-metal targets
- 'ARMv8 deprecated IT blocks' patch finally committed. Will look at
the remaining warnings.
* misc (conf-calls, meetings, emails, ....)
- Connect preparation (slides, ...)
== Next ==
* GCC upstream validation
* GCC/ubsan
* GCC/deprecated-IT blocks
The Linaro Toolchain Working Group (TCWG) is pleased to announce the 2017.09
snapshot of Linaro GCC 6 and 7 source packages.
o The GCC 7 series introduced an ABI change for ARM targets by fixing a bug
(present since GCC 5, see link below) that affects conformance to the procedure
call standard (AAPCS). The bug affects some C++ code where class objects are
passed by value to functions and could result in incorrect or inconsistent code
being generated. If the option -Wpsabi is enabled (on by default) the compiler
will emit a diagnostic note for code that might be affected by this ABI change.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728
For an explanation of the changes please see the following website:
https://gcc.gnu.org/gcc-7/changes.html
o Linaro GCC 7 monthly snapshot[1] is based on FSF GCC 7.2+svn252337 and
includes performance improvements and bug fixes backported from mainline GCC.
The contents of this snapshot will be part of the 2017.11 stable[2] quarterly
release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/7.2-2017.09/
Interesting changes in this GCC source package snapshot include:
* Updates to GCC 7.2+svn252337
* Backports from mainline:
- Backport of [Bugfix] [AArch32] PR target/77308 surprisingly large
stack usage for sha512 on arm
- Backport of [AArch32] Fix ldrd offsets
- Backport of [AArch32] Remove %? string from some Advanced SIMD patterns
- Backport of [AArch64] Add optimized implementation of mersenne twister
- Backport of [AArch64] Add RDMA support to falkor port
- Backport of [AArch64] Fix big endian float immediate moves
- Backport of [AArch64] Fix missing optimization for CMP+AND
- Backport of [AArch64] Fix pattern guard relaxations that are
allowing more constants than they should
- Backport of [AArch64] Fix ThunderX fp vectorizer cost model
- Backport of [AArch64] Generate MLA when multiply + add vector by scalar
- Backport of [AArch64] Implement ALU_BRANCH fusion
- Backport of [AArch64] Improve aarch64 conditional compare usage
- Backport of [AArch64] Improve thunderx_vect_cost some more
- Backport of [AArch64] Move the check for any_condjump_p from
sched-deps to target macros
- Backport of [AArch64] Only allow 0s unconditionally for floating
point values
- Backport of [AArch64] Optimize float immediate moves-HF/DF/SF mode
- Backport of [AArch64] Optimize float immediate moves-infrastructure
- Backport of [AArch64] Optimize float immediate moves-testsuite
- Backport of [AArch64] Optimize integer immediate moves with partial masks
- Backport of [Tesstuite] Fix dg-require-stack-check
- Backport of [Testsuite] [AArch32] Add -mfloat-abi=hard to arm_neon_ok
- Backport of [Testsuite] [AArch64] Fix dbl_mov_immediate_1.c test
- Backport of [Testsuite] [AArch64] gcc.target/aarch64/ccmp_2.c: New test
- Backport of [Cleanup] [AArch32] PR target/68535 arm.c: 5 * set but not used
- Backport of [Doc] [AArch64] Clean up AArch64 options
o Linaro GCC 6 monthly snapshot[1] is based on FSF GCC 6.4+svn252072 and
includes performance improvements and bug fixes backported from mainline GCC.
This snapshot contents will be part of the next maintenance release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.4-2017.09/
Interesting changes in this GCC source package snapshot include:
* Updates to GCC 6.4+svn252072
o Subscribe to the important Linaro mailing lists and join our IRC channels to
stay on top of Linaro development.
** Linaro Toolchain Development "mailing list":
http://lists.linaro.org/mailman/listinfo/linaro-toolchain
** Linaro Toolchain IRC channel on irc.freenode.net at @#linaro-tcwg@
* Bug reports should be filed in bugzilla against GCC product:
http://bugs.linaro.org/enter_bug.cgi?product=GCC
* Interested in commercial support? inquire at "Linaro support":
mailto:support@linaro.org
[1]. Source package snapshots are defined when the compiler is only
put through unit-testing and full validation is not performed.
[2]. Stable source package releases are defined as releases where the
full Linaro Toolchain validation plan is executed.
The Linaro Toolchain Working Group (TCWG) is pleased to announce our first
preview-grade ILP32 binary cross-toolchain.
Linaro is supporting AArch64 community effort to introduce ILP32 ABI for
AArch64 Linux, and TCWG will be providing preview-grade ILP32 binary
cross-toolchains alongside our normal release candidates. These toolchains
will be built using community-supported branches for ILP32 ABI of Linux kernel
and Glibc.
This first delivery is based on Linaro GCC 7.1-2017.08-rc1 sources and
available at:
http://snapshots.linaro.org/components/toolchain/binaries/7.1-2017.08-rc1/a…
Contact Linaro
===============
File bugs at http://bugs.linaro.org
For Linaro member support see http://support.linaro.org
For Linaro community support email linaro-toolchain(a)lists.linaro.org
== Progress ==
* Infrastructure:
- patch reviews
* Benchmarking:
- more experiments to reduce noise.
- board reboot + several iterations + use of only 1 core seems to
give manageable results, at the expense of execution time
- old 'deprecated IT blocks' patch benchmarked again with this setup, seems ok
* GCC upstream validation:
- further reduced noise ("random" pass/failures)
- reported a few regressions, looking at improving some testcases
related to branch-cost on arm
* binutils/gdb upstream validation:
- gdbserver build broken on trusty, sent an email to Yao
* GCC
- investigating portability of ubsan to bare-metal targets
* misc (conf-calls, meetings, emails, ....)
== Next ==
* Benchmarking
* GCC upstream validation
* GCC/ubsan
== Progress ==
o Linaro GCC/Validation
* Working on release process
* Reviewed infra patches
* Still some patches pending on upstream reviews
o LLVM
* Familiarizing with LLVM environment
o Misc
* Various meetings and discussions.
* Booked everything for SFO17
== Plan ==
o Backports for 2017.09 snapshot
* 3 days off
== Progress ==
o Linaro GCC/Validation
* Investigating upstream bugzilla PR81863
* Other patches are still pending on upstream reviews
* Working on release process
o Misc
* Various meetings and discussions.
== Plan ==
o PR81863, ...
== This Week ==
* Type promotion (6/10)
- Benchmarking on ARM and AArch64
- Experimenting with pass order to reduce redundancies
- Preparing the patch to send upstream
* PR78809 (2/10)
- Prototype patch done
- Working through testsuite fallout
* PR78736 (1/10)
- Iteration on upstream feedback. Waiting for approval from Fortran
maintainers for
libgfortran changes
* Misc (1/10)
- Submitted https://review.linaro.org/#/c/21111/
- Meetings
== This Week ==
- Submit patch fo type promotion upstream.
- GNU Cauldron 2017
Status of two weeks.
* Bank holiday on Monday and I am off on Tue and Wed. [6/20]
# Progress #
* TCWG-1159, New design of GDB/GDBserver target description. [4/20]
Post my target description v4 patches. They should be ready to
check in, however, I am sidetracked by GNU Cauldron presentation.
* Cauldron presentation. [5/20]
Write the presentation for my target description work above. Ongoing.
latex+beamer+tikz is quite powerful to make presentation.
* My Linaro Connect SFO17 presentation is accepted.
Need to write it in google doc later.
* Review Alan H.'s patches. [2/20]
* Misc [3/20]
# Plan #
* Finish my Cauldron presentation,
* Commit my target description v4 patches, if time allows,
* Off on Wed, and fly to Prague. Back to office on 14th Sep.
--
Yao Qi
Hi,
On 26 August 2017 at 18:10, Pinski, Andrew <Andrew.Pinski(a)cavium.com> wrote:
>> However there might be pushback from upstream maintainers as this makes the structure bigger
>> by adding a field. This could have implications for memory usage of the compiler.
>
> I looked into the structure, adding this field is not going to make the structure bigger for either ILP32 or LP64 targets. If you want, you use bit-fields; there is one bool already there which means you can fit 8 bits in the same area as currently taken up by that one.
Yes. I should have checked the mem_attrs structure. This does have at
least a byte left unlike some other tightly packed structures (gimple
and some tree structures in gcc).
Thanks,
Kugan
>> Alternatively, we maybe able to get this info from dwarf info when we compile with -g ?
>
> I doubt you can. He wants to know if an instruction is a spill location. The location of a variable might be recorded in -g (if it was an user variable) but not that does present the data for all temps being spilled.
>
> I think the patch is actually a good one in general just needs some cleanup.
>
> As for these comments:
>>> For example, GCC calls `output_asm_insn' directly from the `define_insn'
>>> definition in the aarch64.md file without an insn object(`output_asm_insn'
>>> calls `output_asm_operand_names').
>>> This occurs in "*cb<optab><mode>1" and
>>> "*aarch64_fcvt<su_optab><GPF:mode><GPI:mode>2_mult".
>
> Spills in GCC will always be via the mov* patterns (they are special).
> Now really *aarch64_fcvt<su_optab><GPF:mode><GPI:mode>2_mult should be fixed for a different reason; it does unneeded work. The fix would be something like (untested):
> {
> operands[2] = GEN_INT (aarch64_fpconst_pow_of_2 (operands[2]));
> return "fcvtz<su>\t%<GPI:w>0, %<GPF:s>1, %2";
> }
>
> Thanks,
> Andrew
>
>
> -----Original Message-----
> From: linaro-toolchain [mailto:linaro-toolchain-bounces@lists.linaro.org] On Behalf Of Kugan Vivekanandarajah
> Sent: Saturday, August 26, 2017 12:40 AM
> To: Renato Golin <renato.golin(a)linaro.org>
> Cc: Jim Wilson <jim.wilson(a)linaro.org>; hpc-sig-devel(a)linaro.org; Linaro Toolchain <linaro-toolchain(a)lists.linaro.org>
> Subject: Re: [hpc-sig-devel] GCC extensions for `hcqc'
>
> Hi,
>
> On 26 August 2017 at 04:04, Renato Golin <renato.golin(a)linaro.org> wrote:
>> +linaro-toolchain, hoping to get more eyes into it.
>>
>> cheers,
>> --renato
>>
>> On 25 August 2017 at 17:59, Masaki Arai <masaki.arai(a)linaro.org> wrote:
>>> Hi,
>>>
>>> I extended GCC 7.1(or GCC 7.2) for `hcqc'.
>>> I would be grateful if you could give me a comment about whether this
>>> extension is acceptable and whether this extension should be pushed
>>> upstream.
>
> I think this is a useful info. However there might be pushback from upstream maintainers as this makes the structure bigger by adding a field. This could have implications for memory usage of the compiler.
> Alternatively, we maybe able to get this info from dwarf info when we compile with -g ? Jim may have some input here (cc ing him).
>
> Thanks,
> Kugan
>
>>>
>>> The extended GCC's output using the option ` -fverbose-asm' is as
>>> follows:
>>>
>>> ldr w0, [x29,48] // tmp433, j(8-byte Folded Spill)
>>> ^^^^^^^^^^^^^^^^^^^ This
>>> code shows that this instruction accesses a memory area for spill
>>> codes.
>>> I made the following changes to GCC 7.1(or GCC 7.2).
>>> The related files are under `hcqc/patch/gcc-7.1.0-add'.
>>>
>>> (1) rtl.h
>>>
>>> I added flag information to `struct mem_attrs' that means whether it
>>> is a spill memory area or not.
>>>
>>> +
>>> + /* True if the MEM is for spill. */
>>> + bool for_spill_p;
>>>
>>> Also, I added an access macro for this additional field.
>>>
>>> + /* For a MEM rtx, true if its MEM is for spill. */ #define
>>> + MEM_FOR_SPILL_P(RTX) (get_mem_attrs (RTX)->for_spill_p)
>>> +
>>>
>>> (2) emit-rtl.c
>>>
>>> I added a code to turn on flags for spill memory area in function
>>> `set_mem_attrs_for_spill'.
>>>
>>> + attrs.for_spill_p = true;
>>>
>>> (3) final.c
>>>
>>> I added code to print that information in function
>>> `output_asm_operand_names'
>>> if the memory is a spill memory area,
>>>
>>> +
>>> + if (MEM_P (op) && MEM_FOR_SPILL_P (op))
>>> + {
>>> + HOST_WIDE_INT size = MEM_SIZE (op);
>>> + fprintf (asm_out_file, " (" HOST_WIDE_INT_PRINT_DEC "-byte
>>> + Folded
>>> Spill)", size);
>>> + }
>>>
>>> The above changes are implemented similarly as Clang/LLVM.
>>> Unfortunately, it is difficult for GCC to print the above "(?-byte
>>> Folded Spill)"
>>> for memory access instructions only in the same manner as Clang/LLVM.
>>> The reason is that GCC executes the above `output_asm_operand_names'
>>> even in situations where any instruction object(insn) does not exist
>>> when outputting assembly code.
>>> For example, GCC calls `output_asm_insn' directly from the `define_insn'
>>> definition in the aarch64.md file without an insn object(`output_asm_insn'
>>> calls `output_asm_operand_names').
>>> This occurs in "*cb<optab><mode>1" and
>>> "*aarch64_fcvt<su_optab><GPF:mode><GPI:mode>2_mult".
>>>
>>> From this fact, `hcqc' extracts and accumulates memory access
>>> instructions from the assembly code with the comment "(?-byte Folded
>>> Spill)".
>>>
>>> The above extensions are commonly available on almost any architecture.
>>> Also, these extensions do not affect the execution of the resulting
>>> assembly code since additional outputs are only in comments.
>>>
>>> Best regards,
>>> --
>>> --------------------------------------
>>> Masaki Arai
>>>
>> _______________________________________________
>> linaro-toolchain mailing list
>> linaro-toolchain(a)lists.linaro.org
>> https://lists.linaro.org/mailman/listinfo/linaro-toolchain
> _______________________________________________
> linaro-toolchain mailing list
> linaro-toolchain(a)lists.linaro.org
> https://lists.linaro.org/mailman/listinfo/linaro-toolchain
== Progress ==
o Linaro GCC/Validation
* Delivered monthly source snapshots
* Released GCC 6 and 7 2017.08 binary releases
* Completed PR 80287:
- Added new testcase on trunk and GCC 7 branch.
- Fix backported on gcc-6-branch.
* Investigating upstream bugzilla PR81863
* Other patches are still pending on upstream reviews
o Misc
* Various meetings and discussions.
== Plan ==
o Off until Aug 31th
o PR81863, ...
The Linaro Binary Toolchain
============================
The Linaro GCC 6.4-2017.08 Release is now available.
The GCC 6 Release series has significant changes from the GCC 5
release series. For an explanation of the changes please see the
following website:
https://gcc.gnu.org/gcc-6/changes.html
For help in porting to GCC 6 please see the following explanation:
https://gcc.gnu.org/gcc-6/porting_to.html
Download release packages from:
(sources)
http://releases.linaro.org/components/toolchain/gcc-linaro/6.4-2017.08/
(binaries)
http://releases.linaro.org/components/toolchain/binaries/6.4-2017.08/
Previous snapshots and release-candidates are at:
http://snapshots.linaro.org/components/toolchain/binaries/
Previous releases are at:
http://releases.linaro.org/components/toolchain/binaries/
A description of the arm and AArch64 target triples can be found at:
https://collaborate.linaro.org/display/TCWGPUB/ARM+and+AArch64+Target+Tripl…
Host Requirements
==================
Linaro officially supports the current and previous Ubuntu LTS
releases (as of the time of this release). This does not mean that
the toolchain will not work on other/older Linux distributions. See
the following for the life-time of Ubuntu LTS releases.
https://wiki.ubuntu.com/Releases
The host system upon which the cross-compiler will run requires a
minimum of glibc 2.14, because of API changes to glibc's memcpy API.
https://bugs.linaro.org/show_bug.cgi?id=1869
Package Versions
=================
Linaro GCC 6.4-2017.08
http://releases.linaro.org/components/toolchain/gcc-linaro/6.4-2017.08/
Linaro glibc 2.23 (linaro/2.23/master)
https://lists.gnu.org/archive/html/info-gnu/2016-02/msg00009.html
Linaro newlib 2.4-2016.03 (linaro_2.4-branch)
https://sourceware.org/ml/newlib/2016/msg00370.html
Linaro binutils 2.27 (linaro-local/linaro_binutils-2_27-branch)
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob_plain;f=bin…
Linaro GDB 8.0 (gdb-8.0-branch)
https://lists.gnu.org/archive/html/info-gnu/2016-10/msg00007.html
Linaro toolchain package git branches are hosted at:
http://git.linaro.org/toolchain
NEWS for GCC 6 (as of Linaro GCC 6.4-2017.08)
==============================================
* Previous MinGW hosted version of Linaro GCC C preprocessor failed to
convert character set used for string, character constants, etc. This
is fixed in this release.
Linaro bugzilla #3040 : CC1 and cc1plus cannot convert UTF-8.
https://bugs.linaro.org/show_bug.cgi?id=3040
* The Linaro GCC 6.3-2017.05 snapshot added support for -mpure-code
option to ARMv7-M and ARMv8-M targets. This option ensures functions
are put into sections that contain only code and no data.
* The GDB version was upgraded from GDB 8.0.
* Previous versions of the Linaro GCC 6 toolchain, when -static
-E/—dynamic-list are passed to the linker, might create executables
with dynamic sections which aren’t supported by run-time. This was
exhibited in Perf Tools build system and has been fixed upstream and
backported into Linaro Binutils 2.27 branch.
Linaro bugzilla #2926 : Perf tools compiled statically for AArch64
with Linaro release 6.1 and later ones was not statically linked.
https://bugs.linaro.org/show_bug.cgi?id=2926
* The Linaro GCC 6.3-2017.03 snapshot fixed some ILP32 issues (TLS,
exception handling, …) and these have been incorporated into this
release.
* Previous versions of the Linaro GCC 6 toolchain were incorrectly
generating floating-point code for soft-float Linux targets
(arm-linux-gnueabi, and armeb-linux-gnueabi). This escaped detection
until recently because the soft-float targeted toolchains were
configured to use general-purpose registers for passing floating-point
values (which is what you would expect for soft-float toolchains) and
the intra-routine floating-code was not noticed.
The issue would only show up on targets that were run on hardware that
truly didn't have floating-point hardware where the kernel did not
trap and emulate floating-point routines. This has been solved in
Linaro GCC 6.3-2017.02-rc2 by configuring the toolchain (using
--with-float=soft) to generate code without any floating-point
instructions at all (-mfloat-abi=soft).
https://review.linaro.org/#/c/16968/2
This change should not break compatibility between existing binaries
compiled with these toolchains since the float-point parameter passing
ABI is still the same.
* A bug/regression in the compiler has been identified whereby the
target function that is invoked when calling a "weak" function
directly is the "strong" override, whereas when calling the function
via a pointer the "weak" implementation is used. This would be
noticed as inconsistent function invocation when invoking directly vs.
invoking via function pointer. This issue only affected 32-bit arm
targets. This regression has been fixed upstream and backported into
Linaro GCC 6.3-2017.02-rc2.
GCC PR target/78253: [5/6/7 Regression] [ARM] call weak function
instead of strong when called through pointer.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78253
Linaro bugzilla #2562: ARM GCC 5.2 call weak function instead of
strong when called through pointer
https://bugs.linaro.org/show_bug.cgi?id=2562
* MS Windows does not support symlinks and the MS Windows archive
extractor does not properly deep copy the symlink target
files/directories into the symlinked directory structure when
unpacking the toolchain archive. This causes problems with missing
dependencies when using the Linaro mingw toolchains, as identified in
the following bugs:
https://bugs.linaro.org/show_bug.cgi?id=2684https://bugs.linaro.org/show_bug.cgi?id=2192https://bugs.linaro.org/show_bug.cgi?id=2762
This has been solved by copying files rather than using symlinks when
the mingw targetted toolchain archives are created.
https://review.linaro.org/#/c/16415/
* Users of Linaro's toolchain have encountered problems when building
projects with Autotools (specifically libtool):
https://bugs.linaro.org/show_bug.cgi?id=2764
The Linaro binary toolchain release contained files with a .la suffix
as artifacts of the toolchain build process. These .la files are
helper files for libtool, but unlike a gcc install tree, they are not
position independent and contain full paths. Since these artifacts
contain absolute paths they can actually mislead user invocation of
libtool into not finding required libraries (because they reference
the build tree, not the install location) and hence breaking Autotools
builds. These *.la file artifacts have been removed from Linaro
toolchain binaries because they are unnecessary for users.
* The Linaro GCC 6.3-2017.01 snapshot added further enablement for
ARMv8-M and these have been incorporated into this release.
* Compiling and statically linking some SPEC2006int tests against
tcmalloc have been failing due to a problem with glibc's memory
allocator function overrides. This was fixed upstream:
https://sourceware.org/bugzilla/show_bug.cgi?id=20432
Backported into Linaro glibc 2.23:
commit 058b5a41d56b9a8860dede14d97dd443792d064b
Author: Florian Weimer <fweimer(a)redhat.com>
Date: Fri Aug 26 22:40:27 2016 +0200
malloc: Simplify static malloc interposition [BZ #20432]
* Host binaries for x86_64 linux hosts now have symbols and debug
information stripped in order to reduce the size of the toolchain
binary archives. This reduces the archive size from 1.5G to 600M for
aarch64-linux-gnu target with the gcc-6-branch.
* The GDB version was upgraded from GDB 7.11 in the Linaro GCC
6.1-2016.08 release to GDB 7.12 in the Linaro GCC 6.2-2016.11 release.
* The Linaro GCC 6.2-2016.10 snapshot added AArch32 support for ARMv8.2
and ARMv8m, as well as some AArch64 fixes for ARMv8.2, and bug fixes
merged from FSF GCC 6.2. This is available in the binary toolchain as
of Linaro GCC 6.2-2016.11.
* Basic tuning support for the Qualcomm qdf24xx was added to the Linaro
GCC 6.2-2016.10 snapshot and is available in the binary toolchain as
of Linaro GCC 6.2-2016.11.
* IFUNC was disabled for baremetal targets, as it was causing test-suite
failures, and is presently a Linux only feature.
* The gold linker was added to this binary release.
* Backported malloc_lock fix into Linaro newlib 2.4.
commit 2665915cfc46aa6403bb2efd473c523d3167e0cb
Author: Andre Vieira (lists) <Andre.SimoesDiasVieira(a)arm.com>
Date: Thu Jun 16 12:23:51 2016 +0100
Re-enable malloc_lock for newlib-nano
* Backported rawmemchr patch into Linaro newlib 2.4.
commit e7b1ee2ea6aa3ee1da41976407410e6202a098c5
Author: Wilco Dijkstra <Wilco.Dijkstra(a)arm.com>
Date: Thu May 12 16:16:58 2016 +0000
Add rawmemchr
* Backported strlen fix when using Thumb-2 and -Os -marm into Linaro
newlib 2.4.
commit 5c02bcc086a96b174e1b9e1445a4a1770070107a
Author: Thomas Preud'homme <thomas.preudhomme(a)arm.com>
Date: Wed May 11 17:18:48 2016 -0400
Fix strlen using Thumb-2 with -Os -marm
* Backported fix for semihosting ARM when heapinfo not provided by
debugger into Linaro newlib 2.4.
commit 5c9403eaf40951f8a4f55ed65f661b485ff44be7
Author: David Hoover <spm2(a)dangerous.li>
Date: Thu Apr 21 07:12:24 2016 +0200
Fixed semihosting for ARM when heapinfo not provided by debugger.
* Merged latest FSF glibc release/2.23/master into Linaro glibc 2.23.
* Backported __ASSUME_REQUEUE_PI check Linaro glibc 2.23 branch.
commit 2d20c3bf918cd94ebd4106693adb3a5c9272baba
Author: Adhemerval Zanella <adhemerval.zanella(a)linaro.org>
Date: Tue May 17 10:16:39 2016 -0300
Add runtime check for __ASSUME_REQUEUE_PI (BZ# 18463)
* Backported removal of __ASSUME_SET_ROBUST_LIST from Linaro glibc 2.23
branch.
commit bb8f09d72756186a3d82a1f7b2adcf8bc1fbaed1
Author: Adhemerval Zanella <adhemerval.zanella(a)linaro.org>
Date: Mon May 16 19:01:10 2016 -0300
Remove __ASSUME_SET_ROBUST_LIST
* Backported removal of __ASSUME_FUTEX_LOCK_PI from Linaro glibc 2.23
branch.
commit e48b4e7fed0de06dd7832ead48bea8ebc813a204
Author: Adhemerval Zanella <adhemerval.zanella(a)linaro.org>
Date: Mon May 16 10:35:25 2016 -0300
Remove __ASSUME_FUTEX_LOCK_PI
* Merged latest FSF binutils-2_27-branch into
linaro_binutils-2_27-branch.
* The libwinpthread DLL is now copied into the host bin directory to
satisfy mingw package dependencies.
* Backported GNU Linker fix.
commit fbc6c6763e70cb2376e2de990c7fc54c0ee44a59
Author: Nick Clifton <nickc(a)redhat.com>
Date: Tue Aug 23 09:45:11 2016 +0100
Fix seg-fault in ARM linker when trying to parse a binary file.
* Backported GNU Assembler fix for PR 20364
commit 5fe7ebe5ab43750abf8f490b785d99a1e598e7fd
Author: Nick Clifton <nickc(a)redhat.com>
Date: Fri Aug 5 10:37:57 2016 +0100
Fix the generation of alignment frags in code sections for AArch64.
https://sourceware.org/bugzilla/show_bug.cgi?id=20364
* Performance related backports from the following snapshots have been
included: Linaro GCC 6.1-2016.06, Linaro GCC 6.1-2016.07, Linaro GCC
6.1-2016.08, Linaro GCC 6.2-2016.09, Linaro GCC 6.2-2016.10, Linaro
GCC 6.2-2016.11, Linaro GCC 6.2-2016.12, Linaro GCC 6.3-2017.01,
Linaro GCC 6.3-2017.02, Linaro GCC 6.3-2017.03, Linaro GCC
6.3-2017.04, Linaro GCC 6.3-2017.05, Linaro GCC 6.3-2017.06 and Linaro
GCC 6.4-2017.07 .
See the following Linaro GCC snapshots:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.06/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.07/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.08/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.09/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.10/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.11/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.12/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.01/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.02/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.03/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.04/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.05/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.06/http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.4-2017.07/
Contact Linaro
===============
File bugs at http://bugs.linaro.org
For Linaro member support see http://support.linaro.org
For Linaro community support email linaro-toolchain(a)lists.linaro.org
== This Week ==
* Type promotion (4/10)
- Looking at perf regressions on ppc64
- Enabling at -O2 with vrp removes some perf regressions
- Did benchmarking for code-size
- Issues with benchmarking for performance
* PR78809 (2/10)
- WIP patch
* PR78736 (1/10)
- Updated patch based on upstream feedback
* Public Holiday (2/10)
* Misc (1/10)
- Meetings
== Next Week ==
- type-promotion, PR78736, PR78809
+linaro-toolchain, hoping to get more eyes into it.
cheers,
--renato
On 25 August 2017 at 17:59, Masaki Arai <masaki.arai(a)linaro.org> wrote:
> Hi,
>
> I extended GCC 7.1(or GCC 7.2) for `hcqc'.
> I would be grateful if you could give me a comment about whether
> this extension is acceptable and whether this extension should be
> pushed upstream.
>
> The extended GCC's output using the option ` -fverbose-asm' is
> as follows:
>
> ldr w0, [x29,48] // tmp433, j(8-byte Folded Spill)
> ^^^^^^^^^^^^^^^^^^^
> This code shows that this instruction accesses a memory area
> for spill codes.
> I made the following changes to GCC 7.1(or GCC 7.2).
> The related files are under `hcqc/patch/gcc-7.1.0-add'.
>
> (1) rtl.h
>
> I added flag information to `struct mem_attrs' that means whether
> it is a spill memory area or not.
>
> +
> + /* True if the MEM is for spill. */
> + bool for_spill_p;
>
> Also, I added an access macro for this additional field.
>
> + /* For a MEM rtx, true if its MEM is for spill. */
> + #define MEM_FOR_SPILL_P(RTX) (get_mem_attrs (RTX)->for_spill_p)
> +
>
> (2) emit-rtl.c
>
> I added a code to turn on flags for spill memory area in function
> `set_mem_attrs_for_spill'.
>
> + attrs.for_spill_p = true;
>
> (3) final.c
>
> I added code to print that information in function
> `output_asm_operand_names'
> if the memory is a spill memory area,
>
> +
> + if (MEM_P (op) && MEM_FOR_SPILL_P (op))
> + {
> + HOST_WIDE_INT size = MEM_SIZE (op);
> + fprintf (asm_out_file, " (" HOST_WIDE_INT_PRINT_DEC "-byte Folded
> Spill)", size);
> + }
>
> The above changes are implemented similarly as Clang/LLVM.
> Unfortunately, it is difficult for GCC to print the above "(?-byte Folded
> Spill)"
> for memory access instructions only in the same manner as Clang/LLVM.
> The reason is that GCC executes the above `output_asm_operand_names'
> even in situations where any instruction object(insn) does not exist when
> outputting assembly code.
> For example, GCC calls `output_asm_insn' directly from the `define_insn'
> definition in the aarch64.md file without an insn object(`output_asm_insn'
> calls `output_asm_operand_names').
> This occurs in "*cb<optab><mode>1" and
> "*aarch64_fcvt<su_optab><GPF:mode><GPI:mode>2_mult".
>
> From this fact, `hcqc' extracts and accumulates memory access
> instructions from the assembly code with the comment "(?-byte Folded
> Spill)".
>
> The above extensions are commonly available on almost any architecture.
> Also, these extensions do not affect the execution of the resulting assembly
> code since additional outputs are only in comments.
>
> Best regards,
> --
> --------------------------------------
> Masaki Arai
>
The Linaro Toolchain Working Group (TCWG) is pleased to announce the 2017.08
snapshot of Linaro GCC 6 and 7 source packages.
o The GCC 7 series introduced an ABI change for ARM targets by fixing a bug
(present since GCC 5, see link below) that affects conformance to the procedure
call standard (AAPCS). The bug affects some C++ code where class objects are
passed by value to functions and could result in incorrect or inconsistent code
being generated. If the option -Wpsabi is enabled (on by default) the compiler
will emit a diagnostic note for code that might be affected by this ABI change.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728
For an explanation of the changes please see the following website:
https://gcc.gnu.org/gcc-7/changes.html
o Linaro GCC 7 monthly snapshot[1] is based on FSF GCC 7.2+svn251138 and
includes performance improvements and bug fixes backported from mainline GCC.
The contents of this snapshot will be part of the 2017.11 stable[2] quarterly
release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/7.2-2017.08/
Interesting changes in this GCC source package snapshot include:
* Updates to GCC 7.2+svn251138
* Backports from mainline:
- [Bugfix] [AArch32] PR target/79665: Improve Cortex-A53 shift bypass
- [Bugfix] PR lto/69866 lto1: internal compiler error: in
add_symbol_to_partition_1, at lto/lto-partition.c:158
- [AArch32] Improve Cortex-A53 FP scheduler
- [AArch64] Add rcpc extension
- [AArch64] Do not increase data alignment at -Os and with -fconserve-stack.
- [AArch64] Emit SIMD moves as mov
- [AArch64] Enable software prefetching (-fprefetch-loop-arrays) for
ThunderX 88xxx
- [AArch64] Fix atomic_cmp_exchange_zero_reg_1.c with +lse
- [AArch64] Fix failing lrint inline tests on bare-metal
- [AArch64] Fix ILP32 memory access
- [AArch64] Improve/correct ThunderX 1 cost model for Arith_shift
- [AArch64] Improve dup pattern
- [AArch64] Inline calls to lrint when possible
- [AArch64] Literal vector construction through vcombine is poor
- [Misc] Fold (A / (1 << B)) to (A >> B)
- [Testsuite] [AArch32] Allow arm_arch_*_ok to test several macros
- [Testsuite] [AArch32] Make gcc.target/arm/its.c more robust
- [Testsuite] [AArch32] Require arm_arch_v8a_ok for sdiv_costs_1.c
- [Testsuite] [AArch32] sdiv_costs_1.c: Disable on softfloat
- [Testsuite] [AArch32] sdiv_costs_1.c: Require arm_v8_vfp_ok
- [Testsuite] [AArch32] sdiv_costs_1.c: Use dg-add-options
- [Cleanup] [AArch64] Rearrange the processors in aarch64-cores.def
- [Cleanup] Update comment about is_leaf
- [Doc] [AArch64] Document RcPc extension
o Linaro GCC 6 monthly snapshot[1] is based on FSF GCC 6.4+svn251111 and
includes performance improvements and bug fixes backported from mainline GCC.
This snapshot contents will be part of the next maintenance release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.4-2017.08/
Interesting changes in this GCC source package snapshot include:
* Updates to GCC 6.4+svn251111
o Subscribe to the important Linaro mailing lists and join our IRC channels to
stay on top of Linaro development.
** Linaro Toolchain Development "mailing list":
http://lists.linaro.org/mailman/listinfo/linaro-toolchain
** Linaro Toolchain IRC channel on irc.freenode.net at @#linaro-tcwg@
* Bug reports should be filed in bugzilla against GCC product:
http://bugs.linaro.org/enter_bug.cgi?product=GCC
* Interested in commercial support? inquire at "Linaro support":
mailto:support@linaro.org
[1]. Source package snapshots are defined when the compiler is only
put through unit-testing and full validation is not performed.
[2]. Stable source package releases are defined as releases where the
full Linaro Toolchain validation plan is executed.
* Mon - Wed off [6/10]
# Progress #
* TCWG-1159,New design of GDB/GDBserver target description. [3/10]
Commit another three patches, about GDBserver unit tests. Rebase
patches, and prepare series v4.
* Misc, [1/10]
# Plan #
* TCWG-1162, triage the aarch64-elf GDB test result with QEMU.
* TCWG-1159, rebase my GDB target description patches, and post v4.
--
Yao Qi
