std::optional::value() has undesired exception checking semantics and is
unavailable in some older Xcode. The call sites block std::optional migration.
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Only the main Presburger library under the Presburger directory has been switched to use arbitrary precision. Users have been changed to just cast returned values back to int64_t or to use newly added convenience functions that perform the same cast internally.
The performance impact of this has been tested by checking test runtimes after copy-pasting 100 copies of each function. Affine/simplify-structures.mlir goes from 0.76s to 0.80s after this patch. Its performance sees no regression compared to its original performance at commit 18a06d4f3a before a series of patches that I landed to offset the performance overhead of switching to arbitrary precision.
Affine/canonicalize.mlir and SCF/canonicalize.mlir show no noticable difference, staying at 2.02s and about 2.35s respectively.
Also, for Affine and SCF tests as a whole (no copy-pasting), the runtime remains about 0.09s on average before and after.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D129510
This patch refactors MAF to be defined over the universe in a given space
instead of being defined over a restricted domain.
The reasoning for this refactor is to store division representation for local
variables explicitly for the function outputs. This change is required for
unionLexMax/Min to support local variables which will be upstreamed after this
patch. Another reason for this refactor is to have a flattened form of
AffineMap as MultiAffineFunction.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D131864
This patch replaces mlir::lcm with std::lcm, a C++17 feature.
Note that all the arguments to mlir::lcm are of int64_t with no
implicit type conversion as they are passed to mlir::lcm, which I've
verified by modifying mlir::lcm as:
template <typename TA, typename TB>
inline int64_t lcm(TA a, TB b) {
static_assert(std::is_same_v<TA, int64_t>);
static_assert(std::is_same_v<TB, int64_t>);
:
This can easily overflow and it is possible for these unsigned overflows to result in incorrect results.
For example, the two LCMs could be 641 and 6700417, which multiply to 2^32 + 1, which overflows to 1.
Unsigned overflows already occur in the existing tests.
Also, when switching to arbitrary-precision arithmetic, this results in a many
large integer multiplications resulting in a significant slowdown.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D131184
This patch refactors existing implementations of division representation storage
into a new class, DivisionRepr. This refactoring is done so that the common
division utilities can be shared in an upcoming patch.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D129146
This patch implements a lexicographic max/min union of two PWMAFunctions.
The lexmax/lexmin union of two functions is defined as a function defined on
the union of the input domains of both functions, such that when only one of the
functions are defined, it outputs the same as that function, and if both are
defined, it outputs the lexmax/lexmin of the two outputs. On points where
neither function is defined, the union is not defined either.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D128829
This also changes the space of the returned lexmin for IntegerPolyhedrons;
the symbols in the poly now correspond to symbols in the result rather than dims.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D128933
Should be NFC. We can just do the base conversion manually and avoid
warnings about it. Clang before Clang 13 didn't implement P1825 and
complains:
mlir/lib/Analysis/Presburger/IntegerRelation.cpp:226:10: warning: local variable 'result' will be copied
despite being returned by name [-Wreturn-std-move]
return result;
^~~~~~
mlir/lib/Analysis/Presburger/IntegerRelation.cpp:226:10: note: call 'std::move' explicitly to avoid copying
return result;
^~~~~~
std::move(result)
Also added test cases. Also extend support for `computeReprWithOnlyDivLocals` from `IntegerPolyhedron` to `IntegerRelation` and `PresburgerRelation`.
Depends on D128736.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D128737
Also added test cases to test this. Both IntegerRelation::addLocalFloorDiv and the fixed implementation of subtraction need to compute division inequalities from dividend and divisor, so this also adds helper util functions to avoid duplicating this logic.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D128736
Currently, in the Presburger library, we use the words "variables" and
"identifiers" interchangeably. This patch changes this to only use "variables" to
refer to the variables of PresburgerSpace.
The reasoning behind this change is that the current usage of the word "identifier"
is misleading. variables do not "identify" anything. The information attached to them is the
actual "identifier" for the variable. The word "identifier", will later be used
to refer to the information attached to each variable in space.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D128585
This paves the way for integer-exact projection, and for supporting
non-division locals in subtraction, complement, and equality checks.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D127463
This patch adds support for applying a relation on domain/range of a relation.
Reviewed By: arjunp, ftynse
Differential Revision: https://reviews.llvm.org/D126339
This patch adds support for obtaining a set corresponding to the domain/range
of the relation.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D126326
This patch updates asserts in IntegerRelation::isEqual and
IntegerRelation::isCompatible to allow these functions when number of
local identifiers are different. This change is done to reflect the
algorithmic changes done before this patch.
This patch removes inheritence of MultiAffineFunction from IntegerPolyhedron
and instead makes IntegerPolyhedron as a member.
This patch removes virtualization in MultiAffineFunction and also removes
unnecessary functions inherited from IntegerPolyhedron.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D123921
This patch modifies mergeLocalIds to not delete duplicate local ids in
`this` relation. This allows the ordering of the final local ids for `this`
to be determined more easily, which is generally required when other objects
refer to these local ids.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D123866
This patch removes inheritence from PresburgerSpace in IntegerRelation and
instead makes it a member of these classes.
This is required for three reasons:
- It prevents implicit casting to PresburgerSpace.
- Not all functions of PresburgerSpace need to be exposed by the deriving classes.
- IntegerRelation and IntegerPolyhedron are defined in a PresburgerSpace. It
makes more sense for the space to be a member instead of them inheriting from
a space.
Reviewed By: arjunp, ftynse
Differential Revision: https://reviews.llvm.org/D123585
Normalize some of the division and inequality expressions used,
which can improve performance. Also deduplicate some of the
normalization functionality throughout the Presburger library.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D123314
Add support for computing the symbolic integer lexmin of a polyhedron.
This finds, for every assignment to the symbols, the lexicographically
minimum value attained by the dimensions. For example, the symbolic lexmin
of the set
`(x, y)[a, b, c] : (a <= x, b <= x, x <= c)`
can be written as
```
x = a if b <= a, a <= c
x = b if a < b, b <= c
```
This also finds the set of assignments to the symbols that make the lexmin unbounded.
This was previously landed in da92f92621 and
reverted in b238c252e8 due to a build failure
in the code. Re-landing now with a fixed build.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D122985
Add support for computing the symbolic integer lexmin of a polyhedron.
This finds, for every assignment to the symbols, the lexicographically
minimum value attained by the dimensions. For example, the symbolic lexmin
of the set
`(x, y)[a, b, c] : (a <= x, b <= x, x <= c)`
can be written as
```
x = a if b <= a, a <= c
x = b if a < b, b <= c
```
This also finds the set of assignments to the symbols that make the lexmin unbounded.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D122985
Previously, when an input set had a duplicate division, the duplicates might
be removed by a call to mergeLocalIds due to being detected as being duplicate
for the first time. The subtraction implementation cannot handle existing
locals being removed, so this would lead to unexpected behaviour. Resolve this
by removing all the duplicates up front.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D122826
This patch modifies IntegerPolyhedron, IntegerRelation, PresburgerRelation,
PresburgerSet, PWMAFunction, constructors to take PresburgerSpace instead of
dimensions. This allows information present in PresburgerSpace to be carried
better and allows for a general interface.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D122842
This patch is a cleanup patch that merges PresburgerLocalSpace and
PresburgerSpace. Asserting that there are no locals is shifted to the
users of PresburgerSpace themselves.
The reasoning for this patch is that PresburgerLocalSpace did not contribute
much and only introduced additional complexity as locals could still be present
in PresburgerSpace, just not writable. This could introduce problems if a
PresburgerSpace with locals was copied to PresburgerLocalSpace which expected
no locals in a PresburgerSpace.
Reviewed By: arjunp
Differential Revision: https://reviews.llvm.org/D122353
Add a baseline implementation of support for local ids for `PWMAFunction::valueAt`. This can be made more efficient later if needed by handling locals with known div representations separately.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D122144
It is often necessary to "rollback" IntegerRelations to an earlier state. Although providing full rollback support is non-trivial, we really only need to support the case where the only changes made are to append ids or append constraints, and then rollback these additions. This patch adds support to rollback in such situations by recording the number of ids and constraints of each kind and providing support to truncate the IntegerRelation to those counts by removing appended ids and constraints. This already simplifies subtraction a little bit and will also be useful in the implementation of symbolic integer lexmin.
Reviewed By: Groverkss
Differential Revision: https://reviews.llvm.org/D122178
