Change the `notifyRootUpdated` API to be transaction based.

This means that in-place, or root, updates need to use explicit calls to `startRootUpdate`, `finalizeRootUpdate`, and `cancelRootUpdate`. The major benefit of this change is that it enables in-place updates in DialectConversion, which simplifies the FuncOp pattern for example. The major downside to this is that the cases that *may* modify an operation in-place will need an explicit cancel on the failure branches(assuming that they started an update before attempting the transformation).

PiperOrigin-RevId: 286933674

2 files changed, 5 insertions, 17 deletions

diff --git a/mlir/lib/IR/Block.cpp b/mlir/lib/IR/Block.cpp
index 3abbe1027ce..751ceb1bfb4 100644
--- a/mlir/lib/IR/Block.cpp
+++ b/mlir/lib/IR/Block.cpp
@@ -267,3 +267,8 @@ SuccessorRange::SuccessorRange(Block *block) : SuccessorRange(nullptr, 0) {
     if ((count = term->getNumSuccessors()))
       base = term->getBlockOperands().data();
 }
+
+SuccessorRange::SuccessorRange(Operation *term) : SuccessorRange(nullptr, 0) {
+  if ((count = term->getNumSuccessors()))
+    base = term->getBlockOperands().data();
+}
diff --git a/mlir/lib/IR/PatternMatch.cpp b/mlir/lib/IR/PatternMatch.cpp
index d5749fabc07..50e6eeec982 100644
--- a/mlir/lib/IR/PatternMatch.cpp
+++ b/mlir/lib/IR/PatternMatch.cpp
@@ -170,23 +170,6 @@ void PatternRewriter::cloneRegionBefore(Region &region, Block *before) {
   cloneRegionBefore(region, *before->getParent(), before->getIterator());
 }
 
-/// This method is used as the final notification hook for patterns that end
-/// up modifying the pattern root in place, by changing its operands.  This is
-/// a minor efficiency win (it avoids creating a new operation and removing
-/// the old one) but also often allows simpler code in the client.
-///
-/// The opsToRemoveIfDead list is an optional list of nodes that the rewriter
-/// should remove if they are dead at this point.
-///
-void PatternRewriter::updatedRootInPlace(Operation *op,
-                                         ValueRange valuesToRemoveIfDead) {
-  // Notify the rewriter subclass that we're about to replace this root.
-  notifyRootUpdated(op);
-
-  // TODO: Process the valuesToRemoveIfDead list, removing things and calling
-  // the notifyOperationRemoved hook in the process.
-}
-
 //===----------------------------------------------------------------------===//
 // PatternMatcher implementation
 //===----------------------------------------------------------------------===//