[llvm] [MLIR][Presburger] Define matrix inverse for rational matrices (PR #67382)

[Arjun P via llvm-commits]

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@@ -390,4 +390,68 @@ MPInt IntMatrix::normalizeRow(unsigned row, unsigned cols) {
 
 MPInt IntMatrix::normalizeRow(unsigned row) {
   return normalizeRow(row, getNumColumns());
+}
+
+FracMatrix FracMatrix::identity(unsigned dimension) {
+  FracMatrix matrix(dimension, dimension);
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Superty wrote:

You can use Matrix<T>::identity in this implementation

https://github.com/llvm/llvm-project/pull/67382