When the coefficients of dividend are negative, the gcd may be negative
which will change the sign of dividend and overflow denominator.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D117911
The current state of the top level Analysis/ directory is that it contains two libraries;
a generic Analysis library (free from dialect dependencies), and a LoopAnalysis library
that contains various analysis utilities that originated from Affine loop transformations.
This commit moves the LoopAnalysis to the more appropriate home of `Dialect/Affine/Analysis/`,
given the use and intention of the majority of the code within it. After the move, if there
are generic utilities that would fit better in the top-level Analysis/ directory, we can move
them.
Differential Revision: https://reviews.llvm.org/D117351
This patch moves PresburgerSet to Presburger/ directory. This patch is purely
mechincal, it only moves and renames functionality and tests.
This patch is part of a series of patches to move presburger functionality to
Presburger/ directory.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D116836
This patch moves all presburger functionality from FlatAffineConstraints to
IntegerPolyhedron. This patch is purely mechanical, it only moves and renames
functionality and tests.
This patch is part of a series of patches to move presburger functionality to
Presburger/ directory.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D116681
This commits adds division normalization in the `getDivRepr` function which extracts
the gcd from the dividend and divisor and normalizes them.
Signed-off-by: Prashant Kumar <pk5561@gmail.com>
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D115595
This patch moves LinearTransform to Presburger/ and makes it use
IntegerPolyhedron instead of FlatAffineConstraints. Also modifies its usage in
`FlatAffineConstraints::findIntegerSample` to support the changes.
This patch is part of a series of patches for moving presburger math functionality into Presburger directory.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D116311
This patch replaces usage of FlatAffineConstraints in Simplex with
IntegerPolyhedron. This removes dependency of Simplex on FlatAffineConstraints
and puts it on IntegerPolyhedron, which is part of Presburger library.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D116287
This commit rewrites most existing unittests involving FlatAffineConstraints
to use the parsing utility. This helps to make the tests more understandable.
This relands commit b0e8667b1d, which was
reverted in 6963be1276, with a fix to a unittest
which was incorrectly rewritten before.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D115920
This reverts commit b0e8667b1d.
ASAN/UBSAN bot is broken with this trace:
[ RUN ] FlatAffineConstraintsTest.FindSampleTest
llvm-project/mlir/include/mlir/Support/MathExtras.h:27:15: runtime error: signed integer overflow: 1229996100002 * 809999700000 cannot be represented in type 'long'
#0 0x7f63ace960e4 in mlir::ceilDiv(long, long) llvm-project/mlir/include/mlir/Support/MathExtras.h:27:15
#1 0x7f63ace8587e in ceil llvm-project/mlir/include/mlir/Analysis/Presburger/Fraction.h:57:42
#2 0x7f63ace8587e in operator* llvm-project/llvm/include/llvm/ADT/STLExtras.h:347:42
#3 0x7f63ace8587e in uninitialized_copy<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long>, long *> include/c++/v1/__memory/uninitialized_algorithms.h:36:62
#4 0x7f63ace8587e in uninitialized_copy<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long>, long *> llvm-project/llvm/include/llvm/ADT/SmallVector.h:490:5
#5 0x7f63ace8587e in append<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long>, void> llvm-project/llvm/include/llvm/ADT/SmallVector.h:662:5
#6 0x7f63ace8587e in SmallVector<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long> > llvm-project/llvm/include/llvm/ADT/SmallVector.h:1204:11
#7 0x7f63ace8587e in mlir::FlatAffineConstraints::findIntegerSample() const llvm-project/mlir/lib/Analysis/AffineStructures.cpp:1171:27
#8 0x7f63ae95a84d in mlir::checkSample(bool, mlir::FlatAffineConstraints const&, mlir::TestFunction) llvm-project/mlir/unittests/Analysis/AffineStructuresTest.cpp:37:23
#9 0x7f63ae957545 in mlir::FlatAffineConstraintsTest_FindSampleTest_Test::TestBody() llvm-project/mlir/unittests/Analysis/AffineStructuresTest.cpp:222:3
This commit rewrites most existing unittests involving FlatAffineConstraints to use the parsing utility. This helps to make the tests more understandable.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D115920
When subtracting `b \ c`, when there are divisions in `c`, these division
constraints get added to `b`. `b` must be restored to its original state
when returning, but these added divisions constraints were not removed in
one of the return paths. This patch fixes this and deduplicates the
restoration logic by encapuslating it in a lambda `restoreState`. The patch
also includes a regression test for the bug fix.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D115577
This patch adds support for extracting divisions when the set contains bounds
which are tighter than the division bounds. For example:
```
3q - i + 2 >= 0 <-- Lower bound for 'q'
-3q + i - 1 >= 0 <-- Tighter upper bound for 'q'
```
Here, the actual upper bound for division for `q` would be `-3q + i >= 0`, but
since this actual upper bound is implied by a tighter upper bound, which awe can still
extract the divison.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D115096
The method that was previously used for computing dual variables was incorrect.
This was used in the integer emptiness check algorithm, where this bug could lead to much longer running times. (Due to the way it is used, this never results in an incorrect emptiness check result.)
This patch fixes the dual computation and adds some additional asserts that catch this bug, along with regression test cases that trigger the asserts when the incorrect dual computation is used.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D113803
This patch factors out math functionality that is a subset of Presburger arithmetic and moves it from FlatAffineConstraints to Presburger/IntegerPolyhedron. This patch only moves some parts of the functionality planned to be moved, with subsequent patches moving more functionality. There are three main reasons for this:
1. This split makes the Presburger Library easier and more flexible to use
across MLIR, by not depending on IR.
2. This split allows the Presburger library to be developed independently from
Affine Analysis, with Affine Analysis using this library.
3. With more functionality being upstreamed to the Presburger Library, the
mlir/Analysis directory will be cluttered with Presburger library components
since they depend on math functionality from FlatAffineConstraints. Moving this
functionality to the Presburger directory allows keeping the new functionality
in the Presburger directory.
This patch is part of an ongoing effort to make the Presburger Library easier to use. The motivation for this effort is the feedback received at the LLVM conference from Mehdi and others.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D114674
This patch provides functionality for simplifying `PresburgerSet`s by checking if any `FlatAffineConstraints` in the set is contained in another, and removing such redundant FACs.
This is part of a series of patches to provide functionality for [integer set coalescing](http://impact.gforge.inria.fr/impact2015/papers/impact2015-verdoolaege.pdf) in MLIR.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D110617
The new `getLocalReprs` function also outputs `dividends` and
`denominators` and hence the CheckDivisionRepresentation fn is
modified to take the newer getLocalReprs function into account.
Signed-off-by: Prashant Kumar <pk5561@gmail.com>
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D115146
This patch implements detecting duplicate local identifiers by extracting their
division representation while merging local identifiers.
For example, given the FACs A, B:
```
A: (x, y)[s0] : (exists d0 = [x / 4], d1 = [y / 4]: d0 <= s0, d1 <= s0, x + y >= 2)
B: (x, y)[s0] : (exists d0 = [x / 4], d1 = [y / 4]: d0 <= s0, d1 <= s0, x + y >= 5)
```
The intersection of A and B without this patch would lead to the following FAC:
```
(x, y)[s0] : (exists d0 = [x / 4], d1 = [y / 4], d2 = [x / 4], d3 = [x / 4]: d0 <= s0, d1 <= s0, d2 <= s0, d3 <= s0, x + y >= 2, x + y >= 5)
```
after this patch, merging of local ids will detect that `d0 = d2` and `d1 = d3`,
and the intersection of these two FACs will be (after removing duplicate constraints):
```
(x, y)[s0] : (exists d0 = [x / 4], d1 = [y / 4] : d0 <= s0, d1 <= s0, x + y >= 2, x + y >= 5)
```
This reduces the number of constraints by 2 (constraints) + 4 (2 constraints for each extra division) for this case.
This is used to reduce the output size representation of operations like
PresburgerSet::subtract, PresburgerSet::intersect which require merging local
variables.
Reviewed By: arjunp, bondhugula
Differential Revision: https://reviews.llvm.org/D112867
Revert changes that were meant to be sent as a single commit with
summary for the differential review, but were accidently sent directly.
This reverts commit 3bc5353fc6.
Previously, when adding a constraint to a Simplex that is already marked
as having no solutions (marked empty), the Simplex would be marked empty again,
and a second UnmarkEmpty entry would be pushed to the undo log. When rolling
back, Simplex should be unmarked empty only after rolling back past the
creation of the first constraint that made it empty.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D114613
Previously, the pivot function would only update the non-redundant rows when
pivoting. This is incorrect because in some cases, when rolling back past a
`detectRedundant` call, the basis being used could be different from that which
was used at the time of returning from the `detectRedundant` call. Therefore,
it is important to update the redundant rows as well during pivots. This could
also be triggered by pivots that occur when testing successive constraints for
being redundant in `detectRedundant` after some initial constraints are marked redundant.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D114614
This patch adds functionality to parse FlatAffineConstraints from a
StringRef with the intention to be used for unit tests. This should
make the construction of FlatAffineConstraints easier for testing
purposes.
The patch contains an example usage of the functionality in a unit test that
uses FlatAffineConstraints.
Reviewed By: bondhugula, grosser
Differential Revision: https://reviews.llvm.org/D113275
This patch extends the existing functionality of computing an explicit
representation for local variables, to also get the explicit representation,
instead of only the inequality pairs.
This is required for a future patch to remove redundant local ids based on
their explicit representation.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D113814
This reverts commit bec488b818.
This commit introduced a layering violation between MLIR libraries.
Reverting for now while discussing on the original review thread.
This patch adds functionality to parse FlatAffineConstraints from a
StringRef with the intention to be used for unit tests. This should
make the construction of FlatAffineConstraints easier for testing
purposes.
The patch contains an example usage of the functionality in a unit test that
uses FlatAffineConstraints.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D113275
This patch adds functionality to FlatAffineConstraints to remove local
variables using equalities. This helps in keeping output representation of
FlatAffineConstraints smaller.
This patch is part of a series of patches aimed at generalizing affine
dependence analysis.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D110056
Add support for intersecting, subtracting, complementing and checking equality of sets having divisions.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D110138
This patch refactors the existing implementation of computing an explicit
representation of an identifier as a floordiv in terms of other identifiers and
exposes this computation as a public function.
The computation of this representation is required to support local identifiers
in PresburgerSet subtract, complement and isEqual.
Reviewed By: bondhugula, arjunp
Differential Revision: https://reviews.llvm.org/D106662
The following constructor call (and others) used to be ambiguous:
```
FlatAffineConstraints constraints(0, 0, 0);
```
Differential Revision: https://reviews.llvm.org/D107726
This patch fixes a bug in the existing implementation of detectAsFloorDiv,
where floordivs with numerator with non-zero constant term and floordivs with
numerator only consisting of a constant term were not being detected.
Reviewed By: vinayaka-polymage
Differential Revision: https://reviews.llvm.org/D107214
This results in significant deduplication of code. This patch is not expected to change any functionality, it's just some simplification in preparation for future work. Also slightly simplified some code that was being touched anyway and added some unit tests for some functions that were touched.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D105152
With this, we have complete support for finding integer sample points in FlatAffineConstraints.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D95047
This patch adds support for checking if two PresburgerSets are equal. In particular, one can check if two FlatAffineConstraints are equal by constructing PrebsurgerSets from them and comparing these.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D94915
With this, we have complete support for emptiness checks. This also paves the way for future support to check if two FlatAffineConstraints are equal.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D94272
Lorenzo Chelini