[Parallel] Revert sequential task changes

https://reviews.llvm.org/D148728 introduced `bool Sequential` to unify
`execute` and the old `spawn` without argument. However, sequential
tasks might be ex

[Parallel] Revert sequential task changes

https://reviews.llvm.org/D148728 introduced `bool Sequential` to unify
`execute` and the old `spawn` without argument. However, sequential
tasks might be executed by any worker thread (non-deterministic),
leading to non-determinism output for ld.lld -z nocombreloc (see
https://reviews.llvm.org/D133003).

In addition, the extra member variables have overhead.
This sequential task has only been used for lld parallel relocation
scanning.

This patch restores the behavior before https://reviews.llvm.org/D148728 .

Fix #105958

Pull Request: https://github.com/llvm/llvm-project/pull/109084

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[NFC] Add explicit #include llvm-config.h where its macros are used. (#106621)

Without these explicit includes, removing other headers, who implicitly
include llvm-config.h, may have non-trivial si

[NFC] Add explicit #include llvm-config.h where its macros are used. (#106621)

Without these explicit includes, removing other headers, who implicitly
include llvm-config.h, may have non-trivial side effects.

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Rename llvm::ThreadPool -> llvm::DefaultThreadPool (NFC) (#83702)

The base class llvm::ThreadPoolInterface will be renamed
llvm::ThreadPool in a subsequent commit.

This is a breaking change: cli

Rename llvm::ThreadPool -> llvm::DefaultThreadPool (NFC) (#83702)

The base class llvm::ThreadPoolInterface will be renamed
llvm::ThreadPool in a subsequent commit.

This is a breaking change: clients who use to create a ThreadPool must
now create a DefaultThreadPool instead.

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Fix test bot breakage from 06b617064a997574df409c7d846b6f6b492f5124

This addresses the issue found by: https://lab.llvm.org/buildbot#builders/178/builds/4571

[Support][Parallel] Change check for nested TaskGroups.

This patch changes check for nested TaskGroups so that it allows
parallel execution for TaskGroups. Following pattern would not work
parallell

[Support][Parallel] Change check for nested TaskGroups.

This patch changes check for nested TaskGroups so that it allows
parallel execution for TaskGroups. Following pattern would not work
parallelly with current check:

std::function<void()> Fn = [&]() {
parallel::TaskGroup tg;

tg.spawn([&]() { });
};

ThreadPool Pool;

Pool.async(Fn);
Pool.async(Fn);

Pool.wait();

One of the TaskGroup would work sequentially as current check
verifies overall number of TaskGroup. Two not nested
TaskGroups can work parallelly but current check prevents this.

Also this patch avoids parallel mode for TaskGroup
in parallel::strategy.ThreadsRequested == 1 case.

This patch is a followup of discussion from D142318

Differential Revision: https://reviews.llvm.org/D148984

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[Support][Parallel] Add sequential mode to TaskGroup::spawn().

This patch allows to specify that some part of tasks should be
done in sequential order. It makes it possible to not use
condition oper

[Support][Parallel] Add sequential mode to TaskGroup::spawn().

This patch allows to specify that some part of tasks should be
done in sequential order. It makes it possible to not use
condition operator for separating sequential tasks:

TaskGroup tg;
for () {
if(condition) ==> tg.spawn([](){fn();}, condition)
fn();
else
tg.spawn([](){fn();});
}

It also prevents execution on main thread. Which allows adding
checks for getThreadIndex() function discussed in D142318.

The patch also replaces std::stack with std::deque in the
ThreadPoolExecutor to have natural execution order in case
(parallel::strategy.ThreadsRequested == 1).

Differential Revision: https://reviews.llvm.org/D148728

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Rename parallelForEachN to just parallelFor

Patch created by running:

rg -l parallelForEachN | xargs sed -i '' -c 's/parallelForEachN/parallelFor/'

No behavior change.

Differential Revision: ht

Rename parallelForEachN to just parallelFor

Patch created by running:

rg -l parallelForEachN | xargs sed -i '' -c 's/parallelForEachN/parallelFor/'

No behavior change.

Differential Revision: https://reviews.llvm.org/D128140

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Add parallelTransformReduce and parallelForEachError

parallelTransformReduce is modelled on the C++17 pstl API of
std::transform_reduce, except our wrappers do not use execution policy
parameters.

Add parallelTransformReduce and parallelForEachError

parallelTransformReduce is modelled on the C++17 pstl API of
std::transform_reduce, except our wrappers do not use execution policy
parameters.

parallelForEachError allows loops that contain potentially failing
operations to propagate errors out of the loop. This was one of the
major challenges I encountered while parallelizing PDB type merging in
LLD. Parallelizing a loop with parallelForEachError is not behavior
preserving: the loop will no longer stop on the first error, it will
continue working and report all errors it encounters in a list.

I plan to use this to propagate errors out of LLD's
coff::TpiSource::remapTpiWithGHashes, which currently stores errors an
error in the TpiSource object.

Differential Revision: https://reviews.llvm.org/D90639

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[Support] Move LLD's parallel algorithm wrappers to support

Essentially takes the lld/Common/Threads.h wrappers and moves them to
the llvm/Support/Paralle.h algorithm header.

The changes are:
- Rem

[Support] Move LLD's parallel algorithm wrappers to support

Essentially takes the lld/Common/Threads.h wrappers and moves them to
the llvm/Support/Paralle.h algorithm header.

The changes are:
- Remove policy parameter, since all clients use `par`.
- Rename the methods to `parallelSort` etc to match LLVM style, since
they are no longer C++17 pstl compatible.
- Move algorithms from llvm::parallel:: to llvm::, since they have
"parallel" in the name and are no longer overloads of the regular
algorithms.
- Add range overloads
- Use the sequential algorithm directly when 1 thread is requested
(skips task grouping)
- Fix the index type of parallelForEachN to size_t. Nobody in LLVM was
using any other parameter, and it made overload resolution hard for
for_each_n(par, 0, foo.size(), ...) because 0 is int, not size_t.

Remove Threads.h and update LLD for that.

This is a prerequisite for parallel public symbol processing in the PDB
library, which is in LLVM.

Reviewed By: MaskRay, aganea

Differential Revision: https://reviews.llvm.org/D79390

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[ADT/STLExtras.h] - Add llvm::is_sorted wrapper and update callers.

It can be used to avoid passing the begin and end of a range.
This makes the code shorter and it is consistent with another
wrappe

[ADT/STLExtras.h] - Add llvm::is_sorted wrapper and update callers.

It can be used to avoid passing the begin and end of a range.
This makes the code shorter and it is consistent with another
wrappers we already have.

Differential revision: https://reviews.llvm.org/D78016

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they ar

Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272

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SupportTests: Suppress ParallelTests on mingw for now. Investigating.

llvm-svn: 302766

[Support] Move Parallel algorithms from LLD to LLVM.

Differential Revision: https://reviews.llvm.org/D33024

llvm-svn: 302748