[Mlir-commits] [mlir] [MLIR][Presburger] Implement IntegerRelation::mergeAndAlignSymbols (PR #76736)

[llvmlistbot at llvm.org]

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@@ -1288,6 +1288,38 @@ void IntegerRelation::eliminateRedundantLocalVar(unsigned posA, unsigned posB) {
   removeVar(posB);
 }
 
+/// First merge and align identifiers into `other` from `this`. If an identifier
+/// exists in `other`, then align it; otherwise insert it assuming it is a new
+/// identifier. Then add identifiers that are in `other`, but not in `this` to
+/// `this`.
+void IntegerRelation::mergeAndAlignSymbols(IntegerRelation &other) {
+  assert(space.isUsingIds() && other.space.isUsingIds() &&
+         "Both relations need to have identifers to merge and align");
+
+  unsigned i = 0;
+  for (const Identifier identifier : space.getIds(VarKind::Symbol)) {
+    // Search in `other` starting at position `i` since the left of `i` is
+    // aligned.
+    auto *findBegin = other.space.getIds(VarKind::Symbol).begin() + i;
+    auto *findEnd = other.space.getIds(VarKind::Symbol).end();
+    auto *itr = std::find(findBegin, findEnd, identifier);
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Abhinav271828 wrote:

if the type name is not too large, it may help to write it explicitly?

https://github.com/llvm/llvm-project/pull/76736