[Mlir-commits] [mlir] [MLIR][SCF] Speed up ConditionPropagation (PR #166080)

[Oleksandr Alex Zinenko]

================
@@ -2565,6 +2565,38 @@ struct ConvertTrivialIfToSelect : public OpRewritePattern<IfOp> {
 struct ConditionPropagation : public OpRewritePattern<IfOp> {
   using OpRewritePattern<IfOp>::OpRewritePattern;
 
+  enum class Parent { Then, Else, None };
+
+  static Parent getParentType(Region *toCheck, IfOp op,
+                              DenseMap<Region *, Parent> &cache) {
+    SmallVector<Region *> seen;
+    while (toCheck) {
+      auto found = cache.find(toCheck);
+      if (found != cache.end()) {
+        return found->second;
+      }
+      seen.push_back(toCheck);
+      if (&op.getThenRegion() == toCheck) {
+        for (auto v : seen) {
+          cache[v] = Parent::Then;
+        }
----------------
ftynse wrote:

```suggestion
        for (Region *region : seen)
          cache[region] = Parent::Then;

```

https://github.com/llvm/llvm-project/pull/166080