[BPI] Keep BPI available in loop passes through LoopStandardAnalysisResults

This is analogous to D86156 (which preserves "lossy" BFI in loop
passes). Lossy means that the analysis preserved may not

[BPI] Keep BPI available in loop passes through LoopStandardAnalysisResults

This is analogous to D86156 (which preserves "lossy" BFI in loop
passes). Lossy means that the analysis preserved may not be up to date
with regards to new blocks that are added in loop passes, but BPI will
not contain stale pointers to basic blocks that are deleted by the loop
passes.

This is achieved through BasicBlockCallbackVH in BPI, which calls
eraseBlock that updates the data structures in BPI whenever a basic
block is deleted.

This patch does not have any changes in the upstream pipeline, since
none of the loop passes in the pipeline use BPI currently.
However, since BPI wasn't previously preserved in loop passes, the loop
predication pass was invoking BPI *on the entire
function* every time it ran in an LPM. This caused massive compile time
in our downstream LPM invocation which contained loop predication.

See updated test with an invocation of a loop-pipeline containing loop
predication and -debug-pass turned ON.

Reviewed-By: asbirlea, modimo
Differential Revision: https://reviews.llvm.org/D110438

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[NewPM] Don't mark AA analyses as preserved

Currently all AA analyses marked as preserved are stateless, not taking
into account their dependent analyses. So there's no need to mark them
as preserve

[NewPM] Don't mark AA analyses as preserved

Currently all AA analyses marked as preserved are stateless, not taking
into account their dependent analyses. So there's no need to mark them
as preserved, they won't be invalidated unless their analyses are.

SCEVAAResults was the one exception to this, it was treated like a
typical analysis result. Make it like the others and don't invalidate
unless SCEV is invalidated.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D102032

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[NFC] Reduce include files dependency and AA header cleanup (part 2).

Continuing work started in https://reviews.llvm.org/D92489:

Removed a bunch of includes from "AliasAnalysis.h" and "LoopPassMan

[NFC] Reduce include files dependency and AA header cleanup (part 2).

Continuing work started in https://reviews.llvm.org/D92489:

Removed a bunch of includes from "AliasAnalysis.h" and "LoopPassManager.h".

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D92852

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[LAA] Relax restrictions on early exits in loop structure

his is a preparation patch for supporting multiple exits in the loop vectorizer, by itself it should be mostly NFC. This patch moves the loo

[LAA] Relax restrictions on early exits in loop structure

his is a preparation patch for supporting multiple exits in the loop vectorizer, by itself it should be mostly NFC. This patch moves the loop structure checks from LAA to their respective consumers (where duplicates don't already exist). Moving the checks does end up changing some of the optimization warnings and debug output slightly, but nothing that appears to be a regression.

Why do this? Well, after auditing the code, I can't actually find anything in LAA itself which relies on having all instructions within a loop execute an equal number of times. This patch simply makes this explicit so that if one consumer - say LV in the near future (hopefully) - wants to handle a broader class of loops, it can do so.

Differential Revision: https://reviews.llvm.org/D92066

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[LoopVersion] Unify SCEVChecks and alias check handling (NFC).

This is an initial cleanup of the way LoopVersioning interacts with LAA.

Currently LoopVersioning has 2 ways of initializing things:

[LoopVersion] Unify SCEVChecks and alias check handling (NFC).

This is an initial cleanup of the way LoopVersioning interacts with LAA.

Currently LoopVersioning has 2 ways of initializing things:

1. Passing LAI and passing UseLAIChecks = true
2. Passing UseLAIChecks = false, followed by calling setSCEVChecks and
setAliasChecks.

Both ways of initializing lead to the same result and the duplication
seems more complicated than necessary.

This patch removes the UseLAIChecks flag from the constructor and the
setSCEVChecks & setAliasChecks helpers and move initialization
exclusively to the constructor.

This simplifies things, by providing a single way to initialize
LoopVersioning and reducing duplication.

Reviewed By: Meinersbur, lebedev.ri

Differential Revision: https://reviews.llvm.org/D84406

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[LoopInfo] empty() -> isInnermost(), add isOutermost()

Differential Revision: https://reviews.llvm.org/D82895

[BFI] Make BFI information available through loop passes inside LoopStandardAnalysisResults

~~D65060 uncovered that trying to use BFI in loop passes can lead to non-deterministic behavior when block

[BFI] Make BFI information available through loop passes inside LoopStandardAnalysisResults

~~D65060 uncovered that trying to use BFI in loop passes can lead to non-deterministic behavior when blocks are re-used while retaining old BFI data.~~

~~To make sure BFI is preserved through loop passes a Value Handle (VH) callback is registered on blocks themselves. When a block is freed it now also wipes out the accompanying BFI entry such that stale BFI data can no longer persist resolving the determinism issue. ~~

~~An optimistic approach would be to incrementally update BFI information throughout the loop passes rather than only invalidating them on removed blocks. The issues with that are:~~
~~1. It is not clear how BFI information should be incrementally updated: If a block is duplicated does its BFI information come with? How about if it's split/modified/moved around? ~~
~~2. Assuming we can address these problems the implementation here will be a massive undertaking. ~~

~~There's a known need of BFI in LICM analysis which requires correct but not incrementally updated BFI data. A follow-up change can register BFI in all loop passes so this preserved but potentially lossy data is available to any loop pass that wants it.~~

See: D75341 for an identical implementation of preserving BFI via VH callbacks. The previous statements do still apply but this change no longer has to be in this diff because it's already upstream �� .

This diff also moves BFI to be a part of LoopStandardAnalysisResults since the previous method using getCachedResults now (correctly!) statically asserts (D72893) that this data isn't static through the loop passes.

Testing
Ninja check

Reviewed By: asbirlea, nikic

Differential Revision: https://reviews.llvm.org/D86156

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Fix return status of LoopDistribute

Move code that may update the IR after precondition, so that if precondition
fail, the IR isn't modified.

Differential Revision: https://reviews.llvm.org/D81225

[LAA] Move CheckingPtrGroup/PointerCheck outside class (NFC).

This allows forward declarations of PointerCheck, which in turn reduce
the number of times LoopAccessAnalysis needs to be included.

Ult

[LAA] Move CheckingPtrGroup/PointerCheck outside class (NFC).

This allows forward declarations of PointerCheck, which in turn reduce
the number of times LoopAccessAnalysis needs to be included.

Ultimately this helps with moving runtime check generation to
Transforms/Utils/LoopUtils.h, without having to include it there.

Reviewers: anemet, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D78458

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Sink all InitializePasses.h includes

This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of reco

Sink all InitializePasses.h includes

This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211

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LoopDistribute/LAA: Respect convergent

This case is slightly tricky, because loop distribution should be
allowed in some cases, and not others. As long as runtime dependency
checks don't need to be

LoopDistribute/LAA: Respect convergent

This case is slightly tricky, because loop distribution should be
allowed in some cases, and not others. As long as runtime dependency
checks don't need to be introduced, this should be OK. This is further
complicated by the fact that LoopDistribute partially ignores if LAA
says that vectorization is safe, and then does its own runtime pointer
legality checks.

Note this pass still does not handle noduplicate correctly, as this
should always be forbidden with it. I'm not going to bother trying to
fix it, as it would require more effort and I think noduplicate should
be removed.

https://reviews.llvm.org/D62607

llvm-svn: 363160

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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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[Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes.

When multiple loop transformation are defined in a loop's metadata, their order of execution is defined by the order of thei

[Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes.

When multiple loop transformation are defined in a loop's metadata, their order of execution is defined by the order of their respective passes in the pass pipeline. For instance, e.g.

#pragma clang loop unroll_and_jam(enable)
#pragma clang loop distribute(enable)

is the same as

#pragma clang loop distribute(enable)
#pragma clang loop unroll_and_jam(enable)

and will try to loop-distribute before Unroll-And-Jam because the LoopDistribute pass is scheduled after UnrollAndJam pass. UnrollAndJamPass only supports one inner loop, i.e. it will necessarily fail after loop distribution. It is not possible to specify another execution order. Also,t the order of passes in the pipeline is subject to change between versions of LLVM, optimization options and which pass manager is used.

This patch adds 'followup' attributes to various loop transformation passes. These attributes define which attributes the resulting loop of a transformation should have. For instance,

!0 = !{!0, !1, !2}
!1 = !{!"llvm.loop.unroll_and_jam.enable"}
!2 = !{!"llvm.loop.unroll_and_jam.followup_inner", !3}
!3 = !{!"llvm.loop.distribute.enable"}

defines a loop ID (!0) to be unrolled-and-jammed (!1) and then the attribute !3 to be added to the jammed inner loop, which contains the instruction to distribute the inner loop.

Currently, in both pass managers, pass execution is in a fixed order and UnrollAndJamPass will not execute again after LoopDistribute. We hope to fix this in the future by allowing pass managers to run passes until a fixpoint is reached, use Polly to perform these transformations, or add a loop transformation pass which takes the order issue into account.

For mandatory/forced transformations (e.g. by having been declared by #pragma omp simd), the user must be notified when a transformation could not be performed. It is not possible that the responsible pass emits such a warning because the transformation might be 'hidden' in a followup attribute when it is executed, or it is not present in the pipeline at all. For this reason, this patche introduces a WarnMissedTransformations pass, to warn about orphaned transformations.

Since this changes the user-visible diagnostic message when a transformation is applied, two test cases in the clang repository need to be updated.

To ensure that no other transformation is executed before the intended one, the attribute `llvm.loop.disable_nonforced` can be added which should disable transformation heuristics before the intended transformation is applied. E.g. it would be surprising if a loop is distributed before a #pragma unroll_and_jam is applied.

With more supported code transformations (loop fusion, interchange, stripmining, offloading, etc.), transformations can be used as building blocks for more complex transformations (e.g. stripmining+stripmining+interchange -> tiling).

Reviewed By: hfinkel, dmgreen

Differential Revision: https://reviews.llvm.org/D49281
Differential Revision: https://reviews.llvm.org/D55288

llvm-svn: 348944

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Rename DEBUG macro to LLVM_DEBUG.

The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/

Rename DEBUG macro to LLVM_DEBUG.

The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240

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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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[Dominators] Remove verifyDomTree and add some verifying for Post Dom Trees

Removes verifyDomTree, using assert(verify()) everywhere instead, and
changes verify a little to always run IsSameAsFreshT

[Dominators] Remove verifyDomTree and add some verifying for Post Dom Trees

Removes verifyDomTree, using assert(verify()) everywhere instead, and
changes verify a little to always run IsSameAsFreshTree first in order
to print good output when we find errors. Also adds verifyAnalysis for
PostDomTrees, which will allow checking of PostDomTrees it the same way
we check DomTrees and MachineDomTrees.

Differential Revision: https://reviews.llvm.org/D41298

llvm-svn: 326315

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Add MemorySSA as loop dependency, disabled by default [NFC].

Summary:
First step in adding MemorySSA as dependency for loop pass manager.
Adding the dependency under a flag.

New pass manager: MSSA

Add MemorySSA as loop dependency, disabled by default [NFC].

Summary:
First step in adding MemorySSA as dependency for loop pass manager.
Adding the dependency under a flag.

New pass manager: MSSA pointer in LoopStandardAnalysisResults can be null.
Legacy and new pass manager: Use cl::opt EnableMSSALoopDependency. Disabled by default.

Reviewers: sanjoy, davide, gberry

Subscribers: mehdi_amini, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D40274

llvm-svn: 318772

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[Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 315940

[NFC] Convert OptimizationRemarkEmitter old emit() calls to new closure
parameterized emit() calls

Summary: This is not functional change to adopt new emit() API added in r313691.

Reviewed By: anem

[NFC] Convert OptimizationRemarkEmitter old emit() calls to new closure
parameterized emit() calls

Summary: This is not functional change to adopt new emit() API added in r313691.

Reviewed By: anemet

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38285

llvm-svn: 315476

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Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*

Sync it up with the name of the class actually defined here. This has been
bothering me for a while...

llvm-svn: 315249

Add a wrapper around copy_if in STLExtras; NFC

I will add one more use for this in a later change.

llvm-svn: 295685

[PM] Separate the LoopAnalysisManager from the LoopPassManager and move
the latter to the Transforms library.

While the loop PM uses an analysis to form the IR units, the current
plan is to have the

[PM] Separate the LoopAnalysisManager from the LoopPassManager and move
the latter to the Transforms library.

While the loop PM uses an analysis to form the IR units, the current
plan is to have the PM itself establish and enforce both loop simplified
form and LCSSA. This would be a layering violation in the analysis
library.

Fundamentally, the idea behind the loop PM is to *transform* loops in
addition to running passes over them, so it really seemed like the most
natural place to sink this was into the transforms library.

We can't just move *everything* because we also have loop analyses that
rely on a subset of the invariants. So this patch splits the the loop
infrastructure into the analysis management that has to be part of the
analysis library, and the transform-aware pass manager.

This also required splitting the loop analyses' printer passes out to
the transforms library, which makes sense to me as running these will
transform the code into LCSSA in theory.

I haven't split the unittest though because testing one component
without the other seems nearly intractable.

Differential Revision: https://reviews.llvm.org/D28452

llvm-svn: 291662

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[PM] Rewrite the loop pass manager to use a worklist and augmented run
arguments much like the CGSCC pass manager.

This is a major redesign following the pattern establish for the CGSCC layer to
sup

[PM] Rewrite the loop pass manager to use a worklist and augmented run
arguments much like the CGSCC pass manager.

This is a major redesign following the pattern establish for the CGSCC layer to
support updates to the set of loops during the traversal of the loop nest and
to support invalidation of analyses.

An additional significant burden in the loop PM is that so many passes require
access to a large number of function analyses. Manually ensuring these are
cached, available, and preserved has been a long-standing burden in LLVM even
with the help of the automatic scheduling in the old pass manager. And it made
the new pass manager extremely unweildy. With this design, we can package the
common analyses up while in a function pass and make them immediately available
to all the loop passes. While in some cases this is unnecessary, I think the
simplicity afforded is worth it.

This does not (yet) address loop simplified form or LCSSA form, but those are
the next things on my radar and I have a clear plan for them.

While the patch is very large, most of it is either mechanically updating loop
passes to the new API or the new testing for the loop PM. The code for it is
reasonably compact.

I have not yet updated all of the loop passes to correctly leverage the update
mechanisms demonstrated in the unittests. I'll do that in follow-up patches
along with improved FileCheck tests for those passes that ensure things work in
more realistic scenarios. In many cases, there isn't much we can do with these
until the loop simplified form and LCSSA form are in place.

Differential Revision: https://reviews.llvm.org/D28292

llvm-svn: 291651

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[LDist] Match behavior between invoking via optimization pipeline or opt -loop-distribute

In r267672, where the loop distribution pragma was introduced, I tried
it hard to keep the old behavior for

[LDist] Match behavior between invoking via optimization pipeline or opt -loop-distribute

In r267672, where the loop distribution pragma was introduced, I tried
it hard to keep the old behavior for opt: when opt is invoked
with -loop-distribute, it should distribute the loop (it's off by
default when ran via the optimization pipeline).

As MichaelZ has discovered this has the unintended consequence of
breaking a very common developer work-flow to reproduce compilations
using opt: First you print the pass pipeline of clang
with -debug-pass=Arguments and then invoking opt with the returned
arguments.

clang -debug-pass will include -loop-distribute but the pass is invoked
with default=off so nothing happens unless the loop carries the pragma.
While through opt (default=on) we will try to distribute all loops.

This changes opt's default to off as well to match clang. The tests are
modified to explicitly enable the transformation.

llvm-svn: 290235

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[LoopVersioning] Require loop-simplify form for loop versioning.

Summary:
Requiring loop-simplify form for loop versioning ensures that the
runtime check block always dominates the exit block.

[LoopVersioning] Require loop-simplify form for loop versioning.

Summary:
Requiring loop-simplify form for loop versioning ensures that the
runtime check block always dominates the exit block.

This patch closes #30958 (https://llvm.org/bugs/show_bug.cgi?id=30958).

Reviewers: silviu.baranga, hfinkel, anemet, ashutosh.nema

Subscribers: ashutosh.nema, mzolotukhin, efriedma, hfinkel, llvm-commits

Differential Revision: https://reviews.llvm.org/D27469

llvm-svn: 290116

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