[flang-commits] [flang] [mlir] [mlir][Transforms] Support 1:N mappings in `ConversionValueMapping` (PR #116524)

[Markus Böck via flang-commits]

================
@@ -53,6 +54,55 @@ static void logFailure(llvm::ScopedPrinter &os, StringRef fmt, Args &&...args) {
   });
 }
 
+/// Given two insertion points in the same block, choose the later one.
+static OpBuilder::InsertPoint
+chooseLaterInsertPointInBlock(OpBuilder::InsertPoint a,
+                              OpBuilder::InsertPoint b) {
+  assert(a.getBlock() == b.getBlock() && "expected same block");
+  Block *block = a.getBlock();
+  if (a.getPoint() == block->begin())
+    return b;
+  if (b.getPoint() == block->begin())
+    return a;
+  if (a.getPoint()->isBeforeInBlock(&*b.getPoint()))
+    return b;
+  return a;
+}
+
+/// Helper function that chooses the insertion point among the two given ones
+/// that is later.
+// TODO: Extend DominanceInfo API to work with block iterators.
+static OpBuilder::InsertPoint chooseLaterInsertPoint(OpBuilder::InsertPoint a,
+                                                     OpBuilder::InsertPoint b) {
+  // Case 1: Same block.
+  if (a.getBlock() == b.getBlock())
+    return chooseLaterInsertPointInBlock(a, b);
+
+  // Case 2: Different block, but same region.
+  if (a.getBlock()->getParent() == b.getBlock()->getParent()) {
+    DominanceInfo domInfo;
+    if (domInfo.properlyDominates(a.getBlock(), b.getBlock()))
+      return b;
+    if (domInfo.properlyDominates(b.getBlock(), a.getBlock()))
+      return a;
+    // Neither of the two blocks dominante each other.
+    llvm_unreachable("unable to find valid insertion point");
+  }
+
+  // Case 3: b's region contains a: choose a.
+  if (Operation *aParent = b.getBlock()->getParent()->findAncestorOpInRegion(
----------------
zero9178 wrote:

```suggestion
  if (b.getBlock()->getParent()->findAncestorOpInRegion(
```
This variable is unused. Ditto below

https://github.com/llvm/llvm-project/pull/116524