[Mlir-commits] [mlir] [mlir][linalg] Add more precise memory effects to linalg op (PR #92079)

[Matthias Springer]

================
@@ -1122,29 +1122,38 @@ ParseResult GenericOp::parse(OpAsmParser &parser, OperationState &result) {
 static void getGenericEffectsImpl(
     SmallVectorImpl<SideEffects::EffectInstance<MemoryEffects::Effect>>
         &effects,
-    ValueRange results, const ValueRange inputOperands,
-    ValueRange outputOperands) {
-  for (auto operand : inputOperands) {
+    LinalgOp linalgOp) {
+  ValueRange inputOperands = linalgOp.getDpsInputs();
+  for (auto [index, operand] : llvm::enumerate(inputOperands)) {
     if (!llvm::isa<MemRefType>(operand.getType()))
       continue;
-    effects.emplace_back(MemoryEffects::Read::get(), operand,
-                         SideEffects::DefaultResource::get());
+    if (linalgOp.payloadUsesValueFromOperand(&linalgOp->getOpOperand(index))) {
+      effects.emplace_back(MemoryEffects::Read::get(), operand, 0, true,
+                           SideEffects::DefaultResource::get());
+    }
   }
-  for (auto operand : outputOperands) {
+  unsigned inputOperandSize = inputOperands.size();
+  unsigned usedOutputSize =
+      linalgOp.getOpOperandsMatchingBBargs().size() - inputOperandSize;
+
+  for (auto [index, operand] : llvm::enumerate(linalgOp.getDpsInits())) {
     if (!llvm::isa<MemRefType>(operand.getType()))
       continue;
-    effects.emplace_back(MemoryEffects::Read::get(), operand,
-                         SideEffects::DefaultResource::get());
-    effects.emplace_back(MemoryEffects::Write::get(), operand,
+    if (index < usedOutputSize &&
----------------
matthias-springer wrote:

Why is this needed? `payloadUsesValueFromOperand` should be sufficient. Are you seeing a crash/out-of-bounds access in `getMatchingBlockArgument` without this change? In that case we should update `getMatchingBlockArgument` such that it returns a "null" BlockArgument. And `payloadUsesValueFromOperand` should return `false` is such a case.


https://github.com/llvm/llvm-project/pull/92079