== Progress ==
* Out of office on Monday [2/10]
* Remove exit-on-error flag from CodeGen tests [TCWG-604] [1/10]
- This is a follow-up of TCWG-592: when changing the diag handler,
some of the tests started to fail, so we had to add an exit-on-error
flag to preserve the old behaviour until we can fix the tests.
- Patch fixing one of the AMDGPU tests (PR27761) - in upstream review
- Patch fixing the ARM test (PR27765) - committed upstream
- Submitted a patch removing the flag from llc - accepted upstream,
pending on approval of AMDGPU patch
* Use git worktree in llvm helper scripts [TCWG-587] [2/10]
- Merged. Working on some follow-up stories
- Change interface to llvm-build [TCWG-629] - Modify llvm-build to
accept the targets defined by CMake
- Fix a bug in llvm-env [TCWG-644] - Initially went unnoticed due to
zsh vs bash differences
- Allow cloning from read-only repo [TCWG-652] - This is so non-TCWG
people can use our helper scripts
* ARM: Do not test for CPUs, use SubtargetFeatures [TCWG-623] [5/10]
- Submitted a patch extracting 6 new subtarget features
- Investigating more features that could be extracted
== Plan ==
* OOO on Monday and Tuesday
* ARM: Do not test for CPUs, use SubtargetFeatures [TCWG-623]
== Progress ==
* Validation
- disk full on builders: analysis simply shows that we need more disk :)
- updated "buildapp" job to support building the Linux kernel. We
need more dev packages installed in the *build* schroots for it to
work though.
* Backports/snapshots
- fsf-6 branch merge review
* GCC
- small cleanup in neon* effective-target tests done
- re-testing neon-testgen.ml removal patch
- PR 67591 (ARM v8 Thumb IT blocks deprecated)
- followup on vect.exp's check_vect() support for old arm cores.
* Support
* Misc (conf-calls, meetings, emails, ...)
== Next ==
* Validation:
- patch reviews
* Backports
- restart the ones that failed due do disk space issues
* GCC
- monitor trunk regressions
- fix "check_vect" guard in gcc.dg/vect tests
- hopefully test-neongen.ml removal
- pr 67591
- advsimd tests
== Progress ==
TCWG-611 Initial Thumbv7a support for LLD committed upstream.
Interworking is supported via BLX only. This is enough to run hello
world on a modern arm-linux-gnueabihf target.
TCWG-653 Interworking veneer support for LLD
The existing support for veneers (thunks in LLD terminology) is Mips
specific for non-pi to pi calls. Unless there is something I'm missing
it looks broken in the general case as well.
I have an implementation of minimal veneers that I'm not particular
happy with, but can experiment with to see what the implementation
options are. I am likely to need to go via and RFC first.
Holiday on Friday.
== Next Week ==
Continue working on TCWG-653.
The Linaro Toolchain Working Group (TCWG) is pleased to announce the
2016.06 snapshot of both Linaro GCC 5 and Linaro GCC 6 source
packages.
Linaro GCC 6 monthly snapshot[1] is based on FSF GCC 6.1+svn237469 and
includes performance improvements and bug fixes backported from
mainline GCC. This snapshot contents will be part of the 2016.08
stable[2] quarterly release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.06/
Interesting changes in this GCC source package snapshot include:
* Updates to GCC 6.1+svn237469
* Backport of [Bugfix] [AArch32] PR target/69857 Remove bogus early
return false; in gen_operands_ldrd_strd
* Backport of [AArch32] Add mode to probe_stack set operands
* Backport of [AArch32] arm/ieee754-df.S: Fix typos in comments
* Backport of [AArch32] Do not set ARM_ARCH_ISA_THUMB for armv5
* Backport of [AArch32] Error out for incompatible ARM multilibs
* Backport of [AArch32] Fix costing of sign-extending load in rtx costs
* Backport of [AArch32] Tie operand 1 to operand 0 in AESMC pattern
when fusing AES/AESMC
* Backport of [AArch32] Use proper output modifier for DImode register
in store exclusive patterns
* Backport of [AArch64] 1/4 Add the missing support of vfms_n_f32,
vfmsq_n_f32, vfmsq_n_f64
* Backport of [AArch64] 2/4 Extend vector mutiply by element to all
supported modes
* Backport of [AArch64] 3/4 Reimplement multiply by element to get rid
of inline assembly
* Backport of [AArch64] 4/4 Reimplement vmvn* intrinscis, remove inline assembly
* Backport of [AArch64] Adjust SIMD integer preference
* Backport of [AArch64] Delete ASM_OUTPUT_DEF and fallback to default
.set directive
* Backport of [AArch64] Don't define a macro when a variable will do
* Backport of [AArch64] Fix shift attributes
* Backport of [AArch64] Improve aarch64_case_values_threshold setting
* Backport of [AArch64] print_operand should not fallthrough from
register operand into generic operand
* Backport of [AArch64] Remove aarch64_simd_attr_length_move
* Backport of [AArch64] Set TARGET_OMIT_STRUCT_RETURN_REG to true
* Backport of [AArch64] Simplify ashl<mode>3 expander for SHORT modes
* Backport of [AArch64] Simplify reduc_plus_scal_v2[sd]f sequence
* Backport of [AArch64] Tie operand 1 to operand 0 in AESMC pattern
when AES/AESMC fusion is enabled
* Backport of [AArch64] Update documentation of AArch64 options for GCC6
* Backport of [AArch64] Wrap SHIFT_COUNT_TRUNCATED in brackets
* Backport of [Testsuite] [AArch32] 01/11 Fix typo in vreinterpret.c
test comment
* Backport of [Testsuite] [AArch32] 02/11 Remove useless #ifdefs from
these tests: vmul, vshl and vtst
* Backport of [Testsuite] [AArch32] 03/11 AdvSIMD tests: be more verbose
* Backport of [Testsuite] [AArch32] 04/11 Add forgotten vsliq_n_u64
vsliq_n_s64 tests
* Backport of [Testsuite] [AArch32] 05/11 Add missing
vreinterpretq_p{8,16} tests
* Backport of [Testsuite] [AArch32] 06/11 Add missing vtst_p16 and
vtstq_p16, and vtst_p{8,16} and vtstq_p{8,16} tests
* Backport of [Testsuite] [AArch32] 07/11 Add vget_lane fp16 tests
* Backport of [Testsuite] [AArch32] 08/11 Add missing vstX_lane fp16 tests
* Backport of [Testsuite] [AArch32] 09/11 Add missing vrnd{,a,m,n,p,x} tests
* Backport of [Testsuite] [AArch32] 10/11 Add missing tests for
intrinsics operating on poly64 and poly128 types
* Backport of [Testsuite] [AArch32] 11/11 Add missing tests for
vreinterpret, operating of fp16 type
* Backport of [Testsuite] [AArch64] Fix vmul_elem_1.c on big-endian
* Backport of [Testsuite] [AArch64] Guard float64_t with __aarch64__
* Backport of [Testsuite] [AArch64] Skip cpu-diagnostics tests when
overriding -mcpu
* Backport of [Testsuite] gcc-dg: handle all return values when
shouldfail is set
* Backport of [Testsuite] PR70227, skip g++.dg/lto/pr69589_0.C on
targets without -rdynamic support
* Backport of [Testsuite] PR tree-optimization/57206
* Backport of [Testsuite] Skip tail call tests on Thumb-1 targets
* Backport of [Misc] Increase default value of lto-min-partition to 10000
* Backport of [Misc] introduce --param max-lto-partition for having an
upper bound on partition size
* Backport of [Cleanup] [AArch32] Fix typos in *thumb1_mulsi3 comment
* Backport of [Cleanup] [AArch32] Remove unused TARGET_ARM_V*M macros
* Backport of [Cleanup] [AArch64] Delete obsolete CC_ZESWP and CC_SESWP CC modes
* Backport of [Cleanup] [AArch64] Remove an unused reload hook
* Backport of [Cleanup] Convert conditional compilation on
WORD_REGISTER_OPERATIONS
* Backport of [Cleanup] Remove spurious debug code
* Backport of [Cleanup] Move wrong ChangeLog entry from toplevel to
gcc ChangeLog
* Backport of [Doc] Fix minor doc bugs, signalling typo, major version
changes rare
Linaro GCC 5 monthly snapshot[1] is based on FSF GCC 5.4+svn237113 and
includes performance improvements and bug fixes backported from
mainline GCC. This snapshot contents will be part of the 2016.08
maintenance release.
This snapshot tarball is available on:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/5.4-2016.06/
Interesting changes in this GCC source package snapshot include:
Updates to GCC 5.6+svn237113
* Backport of [Bugfix] [AArch64] [Linaro #2185] PR target/69245: Set
TREE_TARGET_GLOBALS in aarch64_set_current_function when new tree is
the default node to recalculate optab availability
* Backport of [Bugfix] [AArch64] [Linaro #2185] PR target/70002: Make
aarch64_set_current_function play nice with pragma resetting
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":
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[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.
Hi,
I've stumbled across an assembler error message that I don't understand.
bl1/aarch64/bl1_exceptions.S: Assembler messages:
bl1/aarch64/bl1_exceptions.S:53: Error: non-constant expression in
".if" statement
It occurs when building ARM Trusted Firmware with aarch64-linux-gnu-gcc
that ships with Ubuntu 16.04. It does _not_ occur with an older Linaro
toolchain. More details in [1].
The .align directives in the vector_base and vector_entry macros _do_
make a difference. Are they the cause of the problem? Would you
recommend writing the code differently? Or is it a compiler bug?
[1] https://github.com/ARM-software/tf-issues/issues/401
Thanks,
--
Jerome
Hi all,
First sorry for the long message, but I am kinda stuck on an issue
with my split-stack work for aarch64, so any new eyes to check if
I am doing things properly would be really helpful.
I pushed my current work on a local gcc git [1] and glibc [2] branches.
The current code show not issue with the placed C tests, but there
is one elusive GO tests that fails for some reason.
The glibc patch is pretty simple: it adds a tcbhead_t field
(__private_ss) which will be used to hold the split stack thread
value. Different from stack protector, split-stack requires
a pointer per thread and it is used frequently on *every* function
prologue. So faster access is through TCB direct access (one
instruction less than TLS initial-exec). I plan to digress a little
more about why I decided to use TCB access, but in a short the advantages
are:
1. It is faster than TLS initial-exec
2. Does not require any static or dynamic relocation
The rest of patch is just to add a versioned symbol so either static
or dynamic linking fails for an older glibc (to prevent split-stack
binaries to run on non-supported glibcs).
The GCC patch is more complex, but it follows the already implemented
split-stack support on other architectures (x86, powerpc64, s390).
Basically you add hooks to generate the required prologue and other
bits (C varargs requires some work) and add some runtime support on
libgcc (morestack.S).
Split-stack idea is basically as this: let say you have a function
that requires a very large stack allocation that might fail at
runtime (due ulimit -s limit). Split-stack add some instrumentation
that check if the stack allocation will fail based on initial
value and allocates stack segments as required.
So basically a function would be instrumented as:
function foo
ss := TCB::__private_ss
if SP + stack_allocation_size > ss
call __morestack
// function code
What __morestack basically does is create a new stack segment with
some slack (using a platform neutral code), change the stack pointer
and continue run the function. So a stack frame for a function
that called __morestack is as:
foo
\_ __morestack
\_ // function code
And when the function code finished its execution (including all
possible function calls), it returns to __morestack so it restore
the old stack pointer and arguments.
Now, this is the most straightforward usage of __morestack. However
GO language allows a construct [3] that allows a function to register
a callback that is called at end of its scope that allows to 'recover'
from some runtime execution failure.
And this is the remaining GO tests that fails [4]. What it basically
does is run a set of tests that allocate some different structure and
try to access it in different invalid way to check if accessing a
know null pointer is caught by the runtime (GO adds null pointer checks
for some constructs).
9 func main() {
10 ok := true
11 for _, tt := range tests {
12 func() {
13 defer func() {
14 if err := recover(); err == nil {
15 println(tt.name, "did not panic")
16 ok = false
17 }
18 }()
19 tt.fn()
20 }()
21 }
22 if !ok {
23 println("BUG")
24 }
25 }
41 var tests = []struct{
42 name string
43 fn func()
44 }{
76 {"*bigstructp", func() { use(*bigstructp) }},
108 type BigStruct struct {
109 i int
110 j float64
111 k string
112 x [128<<20]byte
113 l []byte
114 }
So basically here it tries to allocate a very big structure (BigStruct with
about 128 MBs) on stack and since it does not have stack allocation it will
need to call __morestack.
Now, if have patient to read until now, the way GCCGO does that is by
throwing an exception to unwind the stack and to add some CFI directives in
both generated code and morestack to correct handling the unwinding.
So if GCC generates the unwind information for the objects and if __morestack
have the correct unwind information it should, so I presume my patch is
failing in either define the correct exception handler directives in
morestack.S or I am failing in generate the correct __morestack call.
The __morestack call is done at 'aarch64_expand_split_stack_prologue' in
my patch as:
--
+ /* Call __morestack with a non-standard call procedure: x10 will hold
+ the requested stack pointer and x11 the required stack size to be
+ copied. */
+ args_size = crtl->args.size >= 0 ? crtl->args.size : 0;
+ reg11 = gen_rtx_REG (DImode, R11_REGNUM);
+ emit_move_insn (reg11, GEN_INT (args_size));
+ use_reg (&call_fusage, reg11);
+
+ /* Set up a minimum frame pointer to call __morestack. The SP is not
+ save on x29 prior so in __morestack x29 points to the called SP. */
+ aarch64_pushwb_pair_reg (DImode, R29_REGNUM, R30_REGNUM, 16);
+
+ insn = emit_call_insn (gen_call (gen_rtx_MEM (DImode, morestack_ref),
+ const0_rtx, const0_rtx));
+ add_function_usage_to (insn, call_fusage);
+
+ reg29 = gen_rtx_REG (Pmode, R29_REGNUM);
+ cfi_ops = alloc_reg_note (REG_CFA_RESTORE, reg29, cfi_ops);
+ reg30 = gen_rtx_REG (Pmode, R30_REGNUM);
+ cfi_ops = alloc_reg_note (REG_CFA_RESTORE, reg30, cfi_ops);
+ insn = emit_insn (aarch64_gen_loadwb_pair (DImode, stack_pointer_rtx,
+ reg29, reg30, 16));
+
+ /* Reset the CFA to be SP + FRAME_SIZE. */
+ new_cfa = stack_pointer_rtx;
+ cfi_ops = alloc_reg_note (REG_CFA_DEF_CFA, new_cfa, cfi_ops);
+ REG_NOTES (insn) = cfi_ops;
+ RTX_FRAME_RELATED_P (insn) = 1;
+
+ emit_use (gen_rtx_REG (DImode, LR_REGNUM));
+
+ emit_insn (gen_split_stack_return ());
--
I do not add any stack frame allocation for the call, so it might a source
of issues.
Another issue might in morestack.S unwinding directives that is not following
the ABI correctly. I am revising it using GCC generated exceptions examples.
[1] https://git.linaro.org/toolchain/gcc.git/shortlog/refs/heads/linaro-local/a…
[2] https://git.linaro.org/toolchain/glibc.git/shortlog/refs/heads/azanella/spl…
[3] https://blog.golang.org/defer-panic-and-recover
[4] gcc/testsuite/go.test/test/nilptr2.go
=== This Week ===
Support for watchpoint un-alligned watchpoint addresses on LLDB
AArch64 [TCWG-367] [3/10]
-- Implementation successful without the need for instruction emulation.
-- Watchpoint hit detection fixed with ptrace reporting hit address correctly.
-- Used up watchpoint HitAddress function to return back the real
address to host.
Investigation of Nexus devices kernel issues.[TCWG-622] [2/10]
-- Figured out steps to build custom kernel for Neuxs7.
-- Kernel fails to boot though.
LLDB hardware watchpoint capability test and skip watchpoint testing
[TCWG-622] [2/10]
-- Submitted a patch to report back correct reason for watchpoint
creation failure.
Miscellaneous [3/10]
-- Meetings, emails, discussions etc.
-- A look into LLDB xfail decorators to fail on the basis of arm ABI.
-- Out of office on Thursday 9th June for visa interview.
=== Next Week ===
Support for watchpoint un-alligned watchpoint addresses on LLDB
AArch64 [TCWG-367]
-- Finish up work, test and submit for review upstream.
LLDB hardware watchpoint capability test and skip watchpoint testing [TCWG-622]
-- Patch review and further progress.
Miscellaneous
-- Testsuite Makefile.rulez update still pending, hopefully will be
done this week.
-- Xfail decorator updates to xfail based on ARM ABI.
=== This Week ===
Investigation of Nexus devices kernel issues.[TCWG-622] [6/10]
-- Figured out source trees for various android devices and checked
out kernel code.
-- Comparison between watchpoint implementation of different kerenel
sources supported by Nexus devices.
-- Figured a way to burn a custom rom with updated kernel on Nexus 7.
-- Figured Kconfig issue that was causing watchpoints not to be
detected on Nexus 7.
-- Watchpoint installation still doesnt work on Nexus 7.
LLDB buildbot updates and maintenance [TCWG-241] [2/10]
-- Upgraded cmake version after migration to new version.
-- Migrating local buildbot setup (builders and testers) to ubuntu xenial 16.04
-- Buildbot restart after power outage.
Miscellaneous [2/10]
-- Meetings, emails, discussions etc.
-- Out of office on Tuesday 31st 2016 for visa documents preparation.
=== Next Week ===
Support for watchpoint un-alligned watchpoint addresses on LLDB
AArch64 [TCWG-367]
-- Continue work on hardware watchpoint support.
Investigation of Nexus devices kernel issues.[TCWG-622]
-- Figured out steps to build custom kernel for Neuxs7.
LLDB hardware watchpoint capability test and skip watchpoint testing [TCWG-622]
-- Investigate possible ways to solve this issue.
Miscellaneous
-- Out of office on Thursday 9th June for visa interview.
* One day off on Thu [2/10]
# Progress #
* TCWG-639, non-8-byte-aligned watchpoint is missed on aarch64. [4/10].
It is caused by limited kernel BAS support. RedHat reports this
problem and posts a patch. Good to see they start to contribute to
aarch64 GDB, but I don't like the patch. Spend much time writing a
prototype to prove their patch is not perfect. We agree to fix this
problem by extend RSP fortunately.
* TCWG-333, [3/10] I follow the way how mips does, and fix some bugs.
* TCWG-547, TCWG-518, blocked in upstream review.
* Misc, meetings. [1/10]
# Plan #
* TCWG-333, TCWG-556.
* Ping TCWG-547, TCWG-518.
--
Yao
