Change D60691 caused some knock-on failures that weren't caught by the
existing tests. Firstly, selecting a CPU that should have had a
restricted FPU (e.g. `-mcpu=cortex-m4`, which should have 16 d-regs
and no double precision) could give the unrestricted version, because
`ARM::getFPUFeatures` returned a list of features including subtracted
ones (here `-fp64`,`-d32`), but `ARMTargetInfo::initFeatureMap` threw
away all the ones that didn't start with `+`. Secondly, the
preprocessor macros didn't reliably match the actual compilation
settings: for example, `-mfpu=softvfp` could still set `__ARM_FP` as
if hardware FP was available, because the list of features on the cc1
command line would include things like `+vfp4`,`-vfp4d16` and clang
didn't realise that one of those cancelled out the other.
I've fixed both of these issues by rewriting `ARM::getFPUFeatures` so
that it returns a list that enables every FP-related feature
compatible with the selected FPU and disables every feature not
compatible, which is more verbose but means clang doesn't have to
understand the dependency relationships between the backend features.
Meanwhile, `ARMTargetInfo::handleTargetFeatures` is testing for all
the various forms of the FP feature names, so that it won't miss cases
where it should have set `HW_FP` to feed into feature test macros.
That in turn caused an ordering problem when handling `-mcpu=foo+bar`
together with `-mfpu=something_that_turns_off_bar`. To fix that, I've
arranged that the `+bar` suffixes on the end of `-mcpu` and `-march`
cause feature names to be put into a separate vector which is
concatenated after the output of `getFPUFeatures`.
Another side effect of all this is to fix a bug where `clang -target
armv8-eabi` by itself would fail to set `__ARM_FEATURE_FMA`, even
though `armv8` (aka Arm v8-A) implies FP-Armv8 which has FMA. That was
because `HW_FP` was being set to a value including only the `FPARMV8`
bit, but that feature test macro was testing only the `VFP4FPU` bit.
Now `HW_FP` ends up with all the bits set, so it gives the right
answer.
Changes to tests included in this patch:
* `arm-target-features.c`: I had to change basically all the expected
results. (The Cortex-M4 test in there should function as a
regression test for the accidental double-precision bug.)
* `arm-mfpu.c`, `armv8.1m.main.c`: switched to using `CHECK-DAG`
everywhere so that those tests are no longer sensitive to the order
of cc1 feature options on the command line.
* `arm-acle-6.5.c`: been updated to expect the right answer to that
FMA test.
* `Preprocessor/arm-target-features.c`: added a regression test for
the `mfpu=softvfp` issue.
Reviewers: SjoerdMeijer, dmgreen, ostannard, samparker, JamesNagurne
Reviewed By: ostannard
Subscribers: srhines, javed.absar, kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62998
llvm-svn: 362791
Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch introduces support for defining
numeric variable in a CHECK directive.
This commit introduces support for defining numeric variable from a
litteral value in the input text. Numeric expressions can then use the
variable provided it is on a later line.
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60386
llvm-svn: 362705
This is the LLVM part of this change, the Clang part contains the full
description in its commit message.
Differential Revision: https://reviews.llvm.org/D60697
llvm-svn: 362600
The big endian PPC buildbots are all failing now due to calls to cache
invalidation in unit tests on data that has only the PROT_EXEC flag set.
This has been an issue all along on FreeBSD but it can affect Linux machines
depending on configuration.
This patch mitigates the issue the same way it is mitigated on FreeBSD.
Since this is needed to bring the buildbots back to green, I plan to commit this
and allow for post-commit review, but I thought I would also post it here for
ease of access/readability.
Differential revision: https://reviews.llvm.org/D62741
llvm-svn: 362412
The recent change D60691 introduced a bug in clang when handling
option combinations such as `-mcpu=cortex-m4 -mfpu=none`. Those
options together should select Cortex-M4 but disable all use of
hardware FP, but in fact, now hardware FP instructions can still be
generated in that mode.
The reason is because the handling of FPUVersion::NONE disables all
the same feature names it used to, of which the base one is `vfp2`.
But now there are further features below that, like `vfp2d16fp` and
(following D60694) `fpregs`, which also need to be turned off to
disable hardware FP completely.
Added a tiny test which double-checks that compiling a simple FP
function doesn't access the FP registers.
Reviewers: SjoerdMeijer, dmgreen
Reviewed By: dmgreen
Subscribers: lebedev.ri, javed.absar, kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62729
llvm-svn: 362380
This adds:
- LLVM subtarget features to make all the new instructions conditional on,
- CPU and FPU names for use on clang's command line, with default FPUs set
so that "armv8.1-m.main+fp" and "armv8.1-m.main+fp.dp" will select the right
FPU features,
- architecture extension names "mve" and "mve.fp",
- ABI build attribute support for v8.1-M (a new value for Tag_CPU_arch) and MVE
(a new actual tag).
Patch mostly by Simon Tatham.
Differential Revision: https://reviews.llvm.org/D60698
llvm-svn: 362090
Those two subtarget features were awkward because their semantics are
reversed: each one indicates the _lack_ of support for something in
the architecture, rather than the presence. As a consequence, you
don't get the behavior you want if you combine two sets of feature
bits.
Each SubtargetFeature for an FP architecture version now comes in four
versions, one for each combination of those options. So you can still
say (for example) '+vfp2' in a feature string and it will mean what
it's always meant, but there's a new string '+vfp2d16sp' meaning the
version without those extra options.
A lot of this change is just mechanically replacing positive checks
for the old features with negative checks for the new ones. But one
more interesting change is that I've rearranged getFPUFeatures() so
that the main FPU feature is appended to the output list *before*
rather than after the features derived from the Restriction field, so
that -fp64 and -d32 can override defaults added by the main feature.
Reviewers: dmgreen, samparker, SjoerdMeijer
Subscribers: srhines, javed.absar, eraman, kristof.beyls, hiraditya, zzheng, Petar.Avramovic, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60691
llvm-svn: 361845
Summary:
Remove all llvm:: prefixes in FileCheck library header and
implementation except for calls to make_unique and make_shared since
both files already use the llvm namespace.
Reviewers: jhenderson, jdenny, probinson, arichardson
Subscribers: hiraditya, arichardson, probinson, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62323
llvm-svn: 361515
Summary:
With now a clear distinction between string and numeric substitutions,
this patch introduces separate classes to represent them with a parent
class implementing the common interface. Diagnostics in
printSubstitutions() are also adapted to not require knowing which
substitution is being looked at since it does not hinder clarity and
makes the implementation simpler.
Reviewers: jhenderson, jdenny, probinson, arichardson
Subscribers: llvm-commits, probinson, arichardson, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62241
llvm-svn: 361446
Summary:
Terminology introduced by [[#]] blocks is confusing and does not
integrate well with existing terminology.
First, variables referred by [[]] blocks are called "pattern variables"
while the text a CHECK directive needs to match is called a "CHECK
pattern". This is inconsistent with variables in [[#]] blocks since
[[#]] blocks are also found in CHECK pattern yet those variables are
called "numeric variable".
Second, the replacing of both [[]] and [[#]] blocks by the value of the
variable or expression they contain is represented by a
FileCheckPatternSubstitution class. The naming refers to being a
substitution in a CHECK pattern but could be wrongly understood as being
a substitution of a pattern variable.
Third and lastly, comments use "numeric expression" to refer both to the
[[#]] blocks as well as to the numeric expressions these blocks contain
which get evaluated at match time.
This patch solves these confusions by
- calling variables in [[]] and [[#]] blocks as string and numeric
variables respectively;
- referring to [[]] and [[#]] as substitution *blocks*, with the former
being a string substitution block and the latter a numeric
substitution block;
- calling [[]] and [[#]] blocks to be replaced by the value of a
variable or expression they contain a substitution (as opposed to
definition when these blocks are used to defined a variable), with the
former being a string substitution and the latter a numeric
substitution;
- renaming the FileCheckPatternSubstitution as a FileCheckSubstitution
class with FileCheckStringSubstitution and
FileCheckNumericSubstitution subclasses;
- restricting the use of "numeric expression" to refer to the expression
that is evaluated in a numeric substitution.
While numeric substitution blocks only support numeric substitutions of
numeric expressions at the moment there are plans to augment numeric
substitution blocks to support numeric definitions as well as both a
numeric definition and numeric substitution in the same numeric
substitution block.
Reviewers: jhenderson, jdenny, probinson, arichardson
Subscribers: hiraditya, arichardson, probinson, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62146
llvm-svn: 361445
Summary:
For big-endian powerpc64, the default ABI is ELFv1. OpenPower ABI ELFv2 is supported when -mabi=elfv2 is specified. FreeBSD support for PowerPC64 ELFv2 ABI with LLVM is in progress[1]. This patch adds an alternative way to specify ELFv2 ABI on target triple [2].
The following results are expected:
ELFv1 when using:
-target powerpc64-unknown-freebsd12.0
-target powerpc64-unknown-freebsd12.0 -mabi=elfv1
-target powerpc64-unknown-freebsd12.0-elfv1
ELFv2 when using:
-target powerpc64-unknown-freebsd12.0 -mabi=elfv2
-target powerpc64-unknown-freebsd12.0-elfv2
[1] https://wiki.freebsd.org/powerpc/llvm-elfv2
[2] https://clang.llvm.org/docs/CrossCompilation.html
Patch by Alfredo Dal'Ava Júnior!
Differential Revision: https://reviews.llvm.org/D61950
llvm-svn: 361355
Rename member 'Size' to 'AllocatedSize' in order to provide a hint that the
allocated size may be different than the requested size. Comments are added to
clarify this point. Updated the InMemoryBuffer in FileOutputBuffer.cpp to track
the requested buffer size.
Patch by Machiel van Hooren. Thanks Machiel!
https://reviews.llvm.org/D61599
llvm-svn: 361195
Summary:
This is a fix to D61574, r360179, that allowed duplicate
OptionCategory's. This change adds a check to make sure a category can
only be added once even if the user passes it twice.
Reviewed By: MaskRay
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61972
llvm-svn: 360913
Summary:
- Use alternative to MAP_ANONYMOUS for allocating mapped memory if it isn't available
- Use strtok_r instead of strsep as part of getting program path
- Don't try to find the width of a terminal using "struct winsize" and TIOCGWINSZ on POSIX builds. These aren't defined under POSIX (even though some platforms make them available when they shouldn't), so just check if we are doing a X/Open or POSIX compliant build first.
Author: daltenty
Reviewers: hubert.reinterpretcast, xingxue, andusy
Reviewed By: hubert.reinterpretcast
Subscribers: MaskRay, jsji, hiraditya, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61326
llvm-svn: 360898
This was mentioned both in https://www.viva64.com/en/b/0629/ and by scan-build checks
........
There's concerns this may just introduce a use-after-free instead.....
llvm-svn: 360770
This reinstates r360578 (git e47362c1ec1ea31b626336cc05822035601c3e57),
reverted in r360653 (git 004393681c25e34e921adccc69ae6378090dee54),
with a fix for the list added in FileCheck.rst to build without error.
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar,
arichardson, rnk
Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar,
arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60385
llvm-svn: 360665
This adds support for the arm64_32 watchOS ABI to LLVM's low level tools,
teaching them about the specific MachO choices and constants needed to
disassemble things.
llvm-svn: 360663
Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch introduces regular numeric
variables which can be set on the command-line.
This commit introduces regular numeric variable that can be set on the
command-line with the -D option to a numeric value. They can then be
used in CHECK patterns in numeric expression with the same shape as
@LINE numeric expression, ie. VAR, VAR+offset or VAR-offset where offset
is an integer literal.
The commit also enable strict whitespace in the verbose.txt testcase to
check that the position or the location diagnostics. It fixes one of the
existing CHECK in the process which was not accurately testing a
location diagnostic (ie. the diagnostic was correct, not the CHECK).
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60385
llvm-svn: 360578
Summary:
This patch adds the following features defined by Arm SVE2 architecture
extension:
sve2, sve2-aes, sve2-sm4, sve2-sha3, bitperm
For existing CPUs these features are declared as unsupported to prevent
scheduler errors.
The specification can be found here:
https://developer.arm.com/docs/ddi0602/latest
Reviewers: SjoerdMeijer, sdesmalen, ostannard, rovka
Reviewed By: SjoerdMeijer, rovka
Subscribers: rovka, javed.absar, tschuett, kristof.beyls, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61513
llvm-svn: 360573
Summary:
If passed, the long option flag makes the CommandLine parser
mimic the behavior or GNU getopt_long. Short options are a single
character prefixed by a single dash, and long options are multiple
characters prefixed by a double dash.
This patch was motivated by the discussion in the following thread:
http://lists.llvm.org/pipermail/llvm-dev/2019-April/131786.html
Reviewed By: MaskRay
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61294
llvm-svn: 360532
Summary:
Fix various issues in code style of method comments:
1) Move all heading comments to all non-static methods near their
declaration in the FileCheck.h header file.
2) Harmonize the action verb in doxygen comments for methods to always
be in third person
3) Use \returns instead of free text "return" and "returns".
4) Document a couple more parameters while at it.
Reviewers: jhenderson, probinson, arichardson
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61445
llvm-svn: 360288
This patch changes the return type of sys::Process::getPageSize to
Expected<unsigned> to account for the fact that the underlying syscalls used to
obtain the page size may fail (see below).
For clients who use the page size as an optimization only this patch adds a new
method, getPageSizeEstimate, which calls through to getPageSize but discards
any error returned and substitues a "reasonable" page size estimate estimate
instead. All existing LLVM clients are updated to call getPageSizeEstimate
rather than getPageSize.
On Unix, sys::Process::getPageSize is implemented in terms of getpagesize or
sysconf, depending on which macros are set. The sysconf call is documented to
return -1 on failure. On Darwin getpagesize is implemented in terms of sysconf
and may also fail (though the manpage documentation does not mention this).
These failures have been observed in practice when highly restrictive sandbox
permissions have been applied. Without this patch, the result is that
getPageSize returns -1, which wreaks havoc on any subsequent code that was
assuming a sane page size value.
<rdar://problem/41654857>
Reviewers: dblaikie, echristo
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59107
llvm-svn: 360221
Summary:
It's not uncommon for separate components to share common
Options, e.g., it's common for related Passes to share Options in
addition to the Pass specific ones.
With this change, components can use OptionCategory's to simply help
output even if some of the options are shared.
Reviewed By: MaskRay
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61574
llvm-svn: 360179
Summary:
1. Enable infrastructure of AVX512_BF16, which is supported for BFLOAT16 in Cooper Lake;
2. Enable VCVTNE2PS2BF16, VCVTNEPS2BF16 and DPBF16PS instructions, which are Vector Neural Network Instructions supporting BFLOAT16 inputs and conversion instructions from IEEE single precision.
VCVTNE2PS2BF16: Convert Two Packed Single Data to One Packed BF16 Data.
VCVTNEPS2BF16: Convert Packed Single Data to Packed BF16 Data.
VDPBF16PS: Dot Product of BF16 Pairs Accumulated into Packed Single Precision.
For more details about BF16 isa, please refer to the latest ISE document: https://software.intel.com/en-us/download/intel-architecture-instruction-set-extensions-programming-reference
Author: LiuTianle
Reviewers: craig.topper, smaslov, LuoYuanke, wxiao3, annita.zhang, RKSimon, spatel
Reviewed By: craig.topper
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60550
llvm-svn: 360017
Summary:
This change enables `cl::Grouping` for short options --
options with names of a single character. This is consistent with GNU
getopt behavior.
Reviewers: rnk, MaskRay
Reviewed By: MaskRay
Subscribers: thopre, cfe-commits, MaskRay, rupprecht, hiraditya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D61270
llvm-svn: 359917
Summary:
By default, `parseCommandLineOptions()` will accept either a
`-` or `--` prefix for long options -- options with names longer than
a single character.
While this change does not affect behavior, it will be helpful with a
subsequent change that requires long options use the `--` prefix.
Reviewers: rnk, thopre
Reviewed By: thopre
Subscribers: thopre, cfe-commits, hiraditya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D61269
llvm-svn: 359909
Though being marked "deprecated" by the Linux man-pages project
(MAP_ANON is a synonym of MAP_ANONYMOUS), it is the mostly widely
available macro - many systems that don't provide MAP_ANONYMOUS have
MAP_ANON. MAP_ANON is also used here and there in compiler-rt.
llvm-svn: 359758
Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch introduces the @LINE numeric
expressions.
This commit introduces a new syntax to express a relation a numeric
value in the input text must have with the line number of a given CHECK
pattern: [[#<@LINE numeric expression>]]. Further commits build on that
to express relations between several numeric values in the input text.
To help with naming, regular variables are renamed into pattern
variables and old @LINE expression syntax is referred to as legacy
numeric expression.
Compared to existing @LINE expressions, this new syntax allow arbitrary
spacing between the component of the expression. It offers otherwise the
same functionality but the commit serves to introduce some of the data
structure needed to support more general numeric expressions.
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60384
llvm-svn: 359741
Summary:
Prior to this patch, the CommandLine parser would strip an
unlimitted number of dashes from options. This patch limits it to
two.
Reviewers: rnk
Reviewed By: rnk
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61229
llvm-svn: 359480
Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch gives earlier and better
diagnostics for the @LINE expressions.
Rather than detect parsing errors at matching time, this commit adds
enhance parsing to detect issues with @LINE expressions at parse time
and diagnose them more accurately.
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60383
llvm-svn: 359475
Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch gives earlier and better
diagnostics for the -D option.
Prior to this change, parsing of -D option was very loose: it assumed
that there is an equal sign (which to be fair is now checked by the
FileCheck executable) and that the part on the left of the equal sign
was a valid variable name. This commit adds logic to ensure that this
is the case and gives diagnostic when it is not, making it clear that
the issue came from a command-line option error. This is achieved by
sharing the variable parsing code into a new function ParseVariable.
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60382
llvm-svn: 359447
Currently, clang's libTooling passes this function a fake argv0, which
means that no libTooling tools can find the standard headers on FreeBSD.
With this change, these will now work on any FreeBSD systems that have
procfs mounted. This isn't the right fix for the libTooling issue, but
it does bring the FreeBSD implementation of getExecutablePath closer to
the Linux and macOS implementations.
llvm-svn: 359427
The slow path (with at least one non US-ASCII) will be slower but that
doesn't matter.
Differential Revision: https://reviews.llvm.org/D61178
llvm-svn: 359294
I added a diagnostic along the lines of `-Wpessimizing-move` to detect `return x = y` suppressing copy elision, but I don't know if the diagnostic is really worth it. Anyway, here are the places where my diagnostic reported that copy elision would have been possible if not for the assignment.
P1155R1 in the post-San-Diego WG21 (C++ committee) mailing discusses whether WG21 should fix this pitfall by just changing the core language to permit copy elision in cases like these.
(Kona update: The bulk of P1155 is proceeding to CWG review, but specifically *not* the parts that explored the notion of permitting copy-elision in these specific cases.)
Reviewed By: dblaikie
Author: Arthur O'Dwyer
Differential Revision: https://reviews.llvm.org/D54885
llvm-svn: 359236
Summary:
There's still a little bit of constant factor that could be trimmed (e.g.
more overloads to avoid round-tripping primitives through json::Value).
But this solves the memory scaling problem, and greatly improves the performance
constant factor, and the API should leave room for optimization if needed.
Adapt TimeProfiler to use it, eliminating almost all the performance regression
from r358476.
Performance test on my machine:
perf stat -r 5 ~/llvmbuild-opt/bin/clang++ -w -S -ftime-trace -mllvm -time-trace-granularity=0 spirit.cpp
Handcrafted JSON (HEAD=r358532 with r358476 reverted): 2480ms
json::Value (HEAD): 2757ms (+11%)
After this patch: 2520 ms (+1.6%)
Reviewers: anton-afanasyev, lebedev.ri
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60804
llvm-svn: 359186
Summary:
Concurrent (e.g. nested) llvm::parallel::for_each() may lead to dead
locks. See PR35788 (fixed by rLLD322041) and PR41508 (fixed by D60757).
When parallel_for_each() is about to return, in ~Latch() called by
~TaskGroup(), a thread (in the default executor) may block in
Latch::sync() waiting for Count to become zero. If all threads in the
default executor are blocked, it is a dead lock.
To fix this, force serial execution if the current TaskGroup is not the
first one. For a nested llvm::parallel::for_each(), this parallelizes
the outermost loop and serializes inner loops.
Differential Revision: https://reviews.llvm.org/D61115
llvm-svn: 359182
yaml2obj might crash on invalid input when unable to parse the YAML.
Recently a crash with a very similar nature was fixed for an empty files.
This patch revisits the fix and does it in yaml::Input instead.
It seems to be more correct way to handle such situation.
With that crash for invalid inputs is also fixed now.
Differential revision: https://reviews.llvm.org/D61059
llvm-svn: 359178
Summary:
We've seen cases of bots failing with:
clang: error: unable to execute command: posix_spawn failed: Interrupted system call
Add a small retry loop to posix_spawn in case this happens. Don't retry too much in case there's some systemic problem going on, but retry a few times.
<rdar://problem/50181448>
Reviewers: Bigcheese, arphaman
Subscribers: jkorous, dexonsmith, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61096
llvm-svn: 359152
First, use the old style of linker initialization for MSVC 2019 in
addition to 2017. MSVC 2019 emits a dynamic initializer for
ManagedStatic when compiled in debug mode, and according to zturner,
also sometimes in release mode. I wasn't able to reproduce that, but it
seems best to stick with the old code that works.
When clang is using the MSVC STL, we have to give ManagedStatic a
constexpr constructor that fully zero initializes all fields, otherwise
it emits a dynamic initializer. The MSVC STL implementation of
std::atomic has a non-trivial (but constexpr) default constructor that
zero initializes the atomic value. Because one of the fields has a
non-trivial constructor, ManagedStatic ends up with a non-trivial ctor.
The ctor is not constexpr, so clang ends up emitting a dynamic
initializer, even though it simply does zero initialization. To make it
constexpr, we must initialize all fields of the ManagedStatic.
However, while the constructor that takes a pointer is marked constexpr,
clang says it does not evaluate to a constant because it contains a cast
from a pointer to an integer. I filed this as:
https://developercommunity.visualstudio.com/content/problem/545566/stdatomic-value-constructor-is-not-actually-conste.html
Once we do that, we can add back the
LLVM_REQUIRE_CONSTANT_INITIALIZATION marker, and so far as I'm aware it
compiles successfully on all supported targets.
llvm-svn: 359135
It turns out that I mesread the man page and fcopyfile(3) does not
actually support COPYFILE_CLONE for files.
<rdar://problem/50148757>
llvm-svn: 359127
