Move debug-only code inside LLVM_DEUG to prevent unused variable warnings.

[Delinearization] Refactoring of fixed-size array delinearization

This is a follow-up patch to D122857 where we added delinearization of
fixed-size arrays to loop cache analysis, which resulted in s

[Delinearization] Refactoring of fixed-size array delinearization

This is a follow-up patch to D122857 where we added delinearization of
fixed-size arrays to loop cache analysis, which resulted in some duplicate
code, i.e., "tryDelinearizeFixedSize()", in LoopCacheCost.cpp and
DependenceAnalysis.cpp. Refactoring is done in this patch.

This patch refactors out the main logic of "tryDelinearizeFixedSize()" as
"tryDelinearizeFixedSizeImpl()" and moves it to Delinearization.cpp, such that
clients can reuse "llvm::tryDelinearizeFixedSizeImpl()" wherever they would
like to delinearize fixed-size arrays. Currently it has two users, i.e.,
DependenceAnalysis.cpp and LoopCacheCost.cpp.

Reviewed By: Meinersbur, #loopoptwg

Differential Revision: https://reviews.llvm.org/D124745

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[LoopInfo] Add getOutermostLoop() (NFC)

This is a recurring pattern, add an API function for it.

[DA] Handle mismatching loop levels by considering them non-linear

To represent various loop levels within a nest, DA implements a special
numbering scheme (see comment atop establishNestingLevels).

[DA] Handle mismatching loop levels by considering them non-linear

To represent various loop levels within a nest, DA implements a special
numbering scheme (see comment atop establishNestingLevels). The goal of
this numbering scheme appears to be representing each unique loop
distinctively by using as little memory as possible. This numbering
scheme is simple when the source and destination of the dependence are
in the same loop. In such cases the level is simply the depth of the
loop in which src and dst reside. When the src and dst are not in the
same loop, we could run into the following situation exposed by
https://reviews.llvm.org/D71539. This patch fixes this by detecting
such cases in checkSubscripts and treating them as non-linear/non-affine.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D110973

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Remove unneeded cl::ZeroOrMore for cl::opt/cl::list options

[llvm] Remove unneeded cl::ZeroOrMore for cl::opt options. NFC

Some cl::ZeroOrMore were added to avoid the `may only occur zero or one times!`
error. More were added due to cargo cult. Since the err

[llvm] Remove unneeded cl::ZeroOrMore for cl::opt options. NFC

Some cl::ZeroOrMore were added to avoid the `may only occur zero or one times!`
error. More were added due to cargo cult. Since the error has been removed,
cl::ZeroOrMore is unneeded.

Also remove cl::init(false) while touching the lines.

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[DA] Refactor with a better API

Refactor from iteratively using BitCastInst::getOperand()
to using stripPointerCasts() instead. This is an improvement
since now we are able to analyze more cases, pl

[DA] Refactor with a better API

Refactor from iteratively using BitCastInst::getOperand()
to using stripPointerCasts() instead. This is an improvement
since now we are able to analyze more cases, please refer
to test cases added in this patch.

Reviewed By: Meinersbur, #loopoptwg

Differential Revision: https://reviews.llvm.org/D123559

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Cleanup includes: LLVMAnalysis

Number of lines output by preprocessor:
before: 1065940348
after: 1065307662

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Diff

Cleanup includes: LLVMAnalysis

Number of lines output by preprocessor:
before: 1065940348
after: 1065307662

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D120659

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[APInt] Normalize naming on keep constructors / predicate methods.

This renames the primary methods for creating a zero value to `getZero`
instead of `getNullValue` and renames predicates like `isAl

[APInt] Normalize naming on keep constructors / predicate methods.

This renames the primary methods for creating a zero value to `getZero`
instead of `getNullValue` and renames predicates like `isAllOnesValue`
to simply `isAllOnes`. This achieves two things:

1) This starts standardizing predicates across the LLVM codebase,
following (in this case) ConstantInt. The word "Value" doesn't
convey anything of merit, and is missing in some of the other things.

2) Calling an integer "null" doesn't make any sense. The original sin
here is mine and I've regretted it for years. This moves us to calling
it "zero" instead, which is correct!

APInt is widely used and I don't think anyone is keen to take massive source
breakage on anything so core, at least not all in one go. As such, this
doesn't actually delete any entrypoints, it "soft deprecates" them with a
comment.

Included in this patch are changes to a bunch of the codebase, but there are
more. We should normalize SelectionDAG and other APIs as well, which would
make the API change more mechanical.

Differential Revision: https://reviews.llvm.org/D109483

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[SCEV] Move getIndexExpressionsFromGEP to delinearize [NFC]

Move delinearization logic out of SCEV [NFC]

None of this logic has anything to do with SCEV's internals, it just uses the existing public APIs. As a result, we can move the code from ScalarEvoluti

Move delinearization logic out of SCEV [NFC]

None of this logic has anything to do with SCEV's internals, it just uses the existing public APIs. As a result, we can move the code from ScalarEvolution.cpp/hpp to Delinearization.cpp/hpp with only minor changes.

This was discussed in advance on today's loop opt call. It turned out to be easy as hoped.

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[DA] control compile-time spent by MIV tests

Function exploreDirections() in DependenceAnalysis implements a recursive
algorithm for refining direction vectors. This algorithm has worst-case
complex

[DA] control compile-time spent by MIV tests

Function exploreDirections() in DependenceAnalysis implements a recursive
algorithm for refining direction vectors. This algorithm has worst-case
complexity of O(3^(n+1)) where n is the number of common loop levels.
In this patch I'm adding a threshold to control the amount of time we
spend in doing MIV tests (which most of the time end up resulting in over
pessimistic direction vectors anyway).

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D107159

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[DependenceAnalysis] Guard analysis using getPointerBase().

D104806 broke some uses of getMinusSCEV() in DependenceAnalysis:
subtraction with different pointer bases returns a SCEVCouldNotCompute.
M

[DependenceAnalysis] Guard analysis using getPointerBase().

D104806 broke some uses of getMinusSCEV() in DependenceAnalysis:
subtraction with different pointer bases returns a SCEVCouldNotCompute.
Make sure we avoid cases involving such subtractions.

Differential Revision: https://reviews.llvm.org/D106099

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[Dependence Analysis] Enable delinearization of fixed sized arrays

Patch by Artem Radzikhovskyy!

Allow delinearization of fixed sized arrays if we can prove that the GEP indices do not overflow the

[Dependence Analysis] Enable delinearization of fixed sized arrays

Patch by Artem Radzikhovskyy!

Allow delinearization of fixed sized arrays if we can prove that the GEP indices do not overflow the array dimensions. The checks applied are similar to the ones that are used for delinearization of parametric size arrays. Make sure that the GEP indices are non-negative and that they are smaller than the range of that dimension.

Changes Summary:

- Updated the LIT tests with more exact values, as we are able to delinearize and apply more exact tests
- profitability.ll - now able to delinearize in all cases, no need to use -da-disable-delinearization-checks flag and run the test twice
- loop-interchange-optimization-remarks.ll - in one of the cases we are able to delinearize without using -da-disable-delinearization-checks
- SimpleSIVNoValidityCheckFixedSize.ll - removed unnecessary "-da-disable-delinearization-checks" flag. Now can get the exact answer without it.
- SimpleSIVNoValidityCheckFixedSize.ll and PreliminaryNoValidityCheckFixedSize.ll - made negative tests more explicit, in order to demonstrate the need for "-da-disable-delinearization-checks" flag

Differential Revision: https://reviews.llvm.org/D101486

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[Dependence Analysis] Fix ExactSIV producing wrong analysis

Patch by Artem Radzikhovskyy!

Symptom: ExactSIV test produced incorrect analysis of dependencies see LIT tests
Bug: At the end of the alg

[Dependence Analysis] Fix ExactSIV producing wrong analysis

Patch by Artem Radzikhovskyy!

Symptom: ExactSIV test produced incorrect analysis of dependencies see LIT tests
Bug: At the end of the algorithm when determining dependence direction original author forgot to divide intermediate results by gcd and round result toward zero

Although this bug can be fixed with significantly fewer changes I opted to write the code in such a way that reflects the original algorithm that Banerjee proposed, for easier reference in the future. This surprisingly results in shorter code, and fewer quotient and max/min calculations.

Changes Summary:

- fixed findGCD to return valid x and y so that they match the function description where: ax - by = gcd(a,b)
- Fixed ExactSIV test, to produce proper results
- Documented the extension of Banerjee's algorithm that the original code author introduced. Banerjee's original algorithm only tested whether Dst depends on Src, the extension also allows us to test whether Src depends on Dst, in one pass.
- ExactRDIV test worked fine. Since it uses findGCD(), it needed to be updated.Since ExactRDIV test has very few changes from the core algorithm of ExactSIV I modified the test to have consistent format as ExactSIV.
- Updated the LIT tests to be testing for correct values.

Differential Revision: https://reviews.llvm.org/D100331

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[NFC][AA] Prepare to convert AliasResult to class with PartialAlias offset.

Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.

Reviewed By: asb

[NFC][AA] Prepare to convert AliasResult to class with PartialAlias offset.

Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D98027

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[AA] Split up LocationSize::unknown()

Currently, we have some confusion in the codebase regarding the
meaning of LocationSize::unknown(): Some parts (including most of
BasicAA) assume that LocationS

[AA] Split up LocationSize::unknown()

Currently, we have some confusion in the codebase regarding the
meaning of LocationSize::unknown(): Some parts (including most of
BasicAA) assume that LocationSize::unknown() only allows accesses
after the base pointer. Some parts (various callers of AA) assume
that LocationSize::unknown() allows accesses both before and after
the base pointer (but within the underlying object).

This patch splits up LocationSize::unknown() into
LocationSize::afterPointer() and LocationSize::beforeOrAfterPointer()
to make this completely unambiguous. I tried my best to determine
which one is appropriate for all the existing uses.

The test changes in cs-cs.ll in particular illustrate a previously
clearly incorrect AA result: We were effectively assuming that
argmemonly functions were only allowed to access their arguments
after the passed pointer, but not before it. I'm pretty sure that
this was not intentional, and it's certainly not specified by
LangRef that way.

Differential Revision: https://reviews.llvm.org/D91649

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[NFC][SCEV] Rename SCEVCastExpr into SCEVIntegralCastExpr

All existing SCEV cast types operate on integers.
D89456 will add SCEVPtrToIntExpr cast expression type.
I believe this is best for consiste

[NFC][SCEV] Rename SCEVCastExpr into SCEVIntegralCastExpr

All existing SCEV cast types operate on integers.
D89456 will add SCEVPtrToIntExpr cast expression type.
I believe this is best for consistency.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D89455

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[Analysis] Drop local maxAPInt/minAPInt helpers. NFCI.

Use standard APIntOps::smax/smin helpers instead.

[NFC] Remove unused GetUnderlyingObject paramenter

Depends on D84617.

Differential Revision: https://reviews.llvm.org/D84621

[NFC] GetUnderlyingObject -> getUnderlyingObject

I am going to touch them in the next patch anyway

DependenceAnalysis.h - reduce AliasAnalysis.h include to forward declaration. NFC.

This requires the replacement of legacy class AliasAnalysis usages with AAResults (which it typedefs to anyhow)

[DA] Delinearization of fixed-size multi-dimensional arrays

Summary:
Currently the dependence analysis in LLVM is unable to compute accurate
dependence vectors for multi-dimensional fixed size array

[DA] Delinearization of fixed-size multi-dimensional arrays

Summary:
Currently the dependence analysis in LLVM is unable to compute accurate
dependence vectors for multi-dimensional fixed size arrays.
This is mainly because the delinearization algorithm in scalar evolution
relies on parametric terms to be present in the access functions. In the
case of fixed size arrays such parametric terms are not present, but we
can use the indexes from GEP instructions to recover the subscripts for
each dimension of the arrays. This patch adds this ability under the
existing option `-da-disable-delinearization-checks`.

Authored By: bmahjour

Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu

Reviewed By: Meinersbur

Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72178

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[NFC][DA] Remove duplicate code in checkSrcSubscript and checkDstSubscript

Summary:
[DA] Move common code in checkSrcSubscript and checkDstSubscript to a
new function checkSubscript. This avoids dup

[NFC][DA] Remove duplicate code in checkSrcSubscript and checkDstSubscript

Summary:
[DA] Move common code in checkSrcSubscript and checkDstSubscript to a
new function checkSubscript. This avoids duplicate code and possible
out of sync in the future.

Reviewers: sebpop, jmolloy, reames

Reviewed By: sebpop

Subscribers: bmahjour, hiraditya, llvm-commits, amehsan

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71087

Patch by zhongduo.

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[DA] Improve dump to show source and sink of the dependence

Summary:
The current da printer shows the dependence without indicating
which instructions are being considered as the src vs dst. It
also

[DA] Improve dump to show source and sink of the dependence

Summary:
The current da printer shows the dependence without indicating
which instructions are being considered as the src vs dst. It
also silently ignores call instructions, despite the fact that
they create confused dependence edges to other memory
instructions. This patch addresses these two issues plus a
couple of minor non-functional improvements.

Authored By: bmahjour

Reviewer: dmgreen, fhahn, philip.pfaffe, chandlerc

Reviewed By: dmgreen, fhahn

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71088

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