[all-commits] [llvm/llvm-project] 79ad5f: [MLIR][Presburger] IntegerPolyhedron: add support ...

[Arjun P via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 79ad5fb2959c076522e207433873bec4c1a48851
      https://github.com/llvm/llvm-project/commit/79ad5fb2959c076522e207433873bec4c1a48851
  Author: Arjun P <arjunpitchanathan at gmail.com>
  Date:   2022-04-05 (Tue, 05 Apr 2022)

  Changed paths:
    M mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
    M mlir/include/mlir/Analysis/Presburger/Matrix.h
    M mlir/include/mlir/Analysis/Presburger/PWMAFunction.h
    M mlir/include/mlir/Analysis/Presburger/Simplex.h
    M mlir/lib/Analysis/Presburger/IntegerRelation.cpp
    M mlir/lib/Analysis/Presburger/Matrix.cpp
    M mlir/lib/Analysis/Presburger/PWMAFunction.cpp
    M mlir/lib/Analysis/Presburger/Simplex.cpp
    M mlir/unittests/Analysis/Presburger/IntegerPolyhedronTest.cpp

  Log Message:
  -----------
  [MLIR][Presburger] IntegerPolyhedron: add support for symbolic integer lexmin

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 da92f92621e28a56fe8ad79d82eb60e436bf1d39 and
reverted in b238c252e8b1bbebc7ed79c08e06c23514d0dfb4 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