[Mlir-commits] [mlir] [MLIR][Affine] Rewrite fusion helper hasNonAffineUsersOnPath for efficiency (PR #115588)

[Arnab Dutta]

================
@@ -343,61 +343,48 @@ static Value createPrivateMemRef(AffineForOp forOp, Operation *srcStoreOpInst,
   return newMemRef;
 }
 
-/// Walking from node 'srcId' to node 'dstId' (exclusive of 'srcId' and
-/// 'dstId'), if there is any non-affine operation accessing 'memref', return
-/// true. Otherwise, return false.
-static bool hasNonAffineUsersOnThePath(unsigned srcId, unsigned dstId,
-                                       Value memref,
-                                       MemRefDependenceGraph *mdg) {
-  auto *srcNode = mdg->getNode(srcId);
-  auto *dstNode = mdg->getNode(dstId);
-  Value::user_range users = memref.getUsers();
-  // For each MemRefDependenceGraph's node that is between 'srcNode' and
-  // 'dstNode' (exclusive of 'srcNodes' and 'dstNode'), check whether any
-  // non-affine operation in the node accesses the 'memref'.
-  for (auto &idAndNode : mdg->nodes) {
-    Operation *op = idAndNode.second.op;
-    // Take care of operations between 'srcNode' and 'dstNode'.
-    if (srcNode->op->isBeforeInBlock(op) && op->isBeforeInBlock(dstNode->op)) {
-      // Walk inside the operation to find any use of the memref.
-      // Interrupt the walk if found.
-      auto walkResult = op->walk([&](Operation *user) {
-        // Skip affine ops.
-        if (isa<AffineMapAccessInterface>(*user))
-          return WalkResult::advance();
-        // Find a non-affine op that uses the memref.
-        if (llvm::is_contained(users, user))
-          return WalkResult::interrupt();
-        return WalkResult::advance();
-      });
-      if (walkResult.wasInterrupted())
-        return true;
-    }
-  }
-  return false;
+/// Returns true if there are any non-affine uses of `memref` in any of
+/// the operations between `start` and `end` (both exclusive). Any other
+/// than affine read/write are treated as non-affine uses of `memref`.
+static bool hasNonAffineUsersOnPath(Operation *start, Operation *end,
+                                    Value memref) {
+  assert(start->getBlock() == end->getBlock());
+  assert(start->isBeforeInBlock(end) && "start expected to be before end");
+  Block *block = start->getBlock();
+  // Check if there is a non-affine memref user in any op between `start` and
+  // `end`.
+  return llvm::any_of(memref.getUsers(), [&](Operation *user) {
+    if (isa<AffineReadOpInterface, AffineWriteOpInterface>(user))
+      return false;
+    Operation *ancestor = block->findAncestorOpInBlock(*user);
+    return ancestor && start->isBeforeInBlock(ancestor) &&
+           ancestor->isBeforeInBlock(end);
+  });
 }
 
-/// Check whether a memref value in node 'srcId' has a non-affine that
-/// is between node 'srcId' and node 'dstId' (exclusive of 'srcNode' and
-/// 'dstNode').
-static bool hasNonAffineUsersOnThePath(unsigned srcId, unsigned dstId,
-                                       MemRefDependenceGraph *mdg) {
-  // Collect memref values in node 'srcId'.
-  auto *srcNode = mdg->getNode(srcId);
+/// Check whether a memref value used in any operation of 'src' has a
+/// non-affine operation that is between `src` and `end` (exclusive of `src`
+/// and `end`)  where `src` and `end` are expected to be in the same `Block`.
+/// Any other than affine read/write are treated as non-affine uses of `memref`.
+static bool hasNonAffineUsersOnPath(Operation *src, Operation *end) {
+  assert(src->getBlock() == end->getBlock() && "same block expected");
+
+  // Trivial case. src and end are exclusive.
----------------
arnab-oss wrote:

func args to be placed under backticks.

https://github.com/llvm/llvm-project/pull/115588