[mlir] introduce transform.collect_matching (#76724)

Introduce a new match combinator into the transform dialect. This
operation collects all operations that are yielded by a satisfactory
match into its results. This is a simpler version of `foreach_match`
that can be inserted directly into existing transform scripts.

Author: ftynse

mlir/include/mlir/Dialect/Transform/IR/TransformOps.td

@@ -460,6 +460,39 @@ def NumAssociationsOp : TransformDialectOp<"num_associations",
   let hasVerifier = 1;
 }
 
+def CollectMatchingOp : TransformDialectOp<"collect_matching", [
+    DeclareOpInterfaceMethods<MemoryEffectsOpInterface>,
+    DeclareOpInterfaceMethods<SymbolUserOpInterface>,
+    DeclareOpInterfaceMethods<TransformOpInterface>]> {
+  let summary = "Collects all payload ops that match the given named matcher";
+  let description = [{
+    Collects operations or other payload IR objects nested under `root`
+    (inclusive) that match the given matcher expressed as a named sequence. The
+    matcher sequence must accept exactly one argument that it is not allowed to
+    modify. It must yield as many values as this op has results. Each of the
+    yielded values must be associated with exactly one payload object. If any
+    operation in the matcher sequence produces a silenceable failure, the
+    matcher advances to the next payload operation in the walk order without
+    finishing the sequence.
+
+    The i-th result of this operation is constructed by concatenating the i-th
+    yielded payload IR objects of all successful matcher sequence applications.
+    All results are guaranteed to be mapped to the same number of payload IR
+    objects.
+
+    The operation succeeds unless the matcher sequence produced a definite
+    failure for any invocation.
+  }];
+
+  let arguments = (ins TransformHandleTypeInterface:$root,
+                       SymbolRefAttr:$matcher);
+  let results = (outs Variadic<Transform_AnyHandleOrParamType>:$results);
+
+  let assemblyFormat = [{
+    $matcher `in` $root attr-dict `:` functional-type($root, $results)
+  }];
+}
+
 def ForeachMatchOp : TransformDialectOp<"foreach_match", [
     DeclareOpInterfaceMethods<MemoryEffectsOpInterface>,
     DeclareOpInterfaceMethods<SymbolUserOpInterface>,
@@ -674,7 +707,7 @@ def GetParentOp : TransformDialectOp<"get_parent_op",
 
 def GetProducerOfOperand : TransformDialectOp<"get_producer_of_operand",
     [DeclareOpInterfaceMethods<TransformOpInterface>,
-     NavigationTransformOpTrait, MemoryEffectsOpInterface]> {
+     NavigationTransformOpTrait, MatchOpInterface, MemoryEffectsOpInterface]> {
   let summary = "Get handle to the producer of this operation's operand number";
   let description = [{
     The handle defined by this Transform op corresponds to operation that

mlir/lib/Dialect/Transform/IR/TransformOps.cpp

@@ -22,6 +22,7 @@
 #include "mlir/IR/Verifier.h"
 #include "mlir/Interfaces/ControlFlowInterfaces.h"
 #include "mlir/Interfaces/FunctionImplementation.h"
+#include "mlir/Interfaces/FunctionInterfaces.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Pass/PassManager.h"
 #include "mlir/Pass/PassRegistry.h"
@@ -783,7 +784,7 @@ bool transform::CastOp::areCastCompatible(TypeRange inputs, TypeRange outputs) {
 }
 
 //===----------------------------------------------------------------------===//
-// ForeachMatchOp
+// CollectMatchingOp
 //===----------------------------------------------------------------------===//
 
 /// Applies matcher operations from the given `block` assigning `op` as the
@@ -822,6 +823,137 @@ matchBlock(Block &block, Operation *op, transform::TransformState &state,
   return DiagnosedSilenceableFailure::success();
 }
 
+/// Returns `true` if both types implement one of the interfaces provided as
+/// template parameters.
+template <typename... Tys>
+static bool implementSameInterface(Type t1, Type t2) {
+  return ((isa<Tys>(t1) && isa<Tys>(t2)) || ... || false);
+}
+
+/// Returns `true` if both types implement one of the transform dialect
+/// interfaces.
+static bool implementSameTransformInterface(Type t1, Type t2) {
+  return implementSameInterface<transform::TransformHandleTypeInterface,
+                                transform::TransformParamTypeInterface,
+                                transform::TransformValueHandleTypeInterface>(
+      t1, t2);
+}
+
+//===----------------------------------------------------------------------===//
+// CollectMatchingOp
+//===----------------------------------------------------------------------===//
+
+DiagnosedSilenceableFailure
+transform::CollectMatchingOp::apply(transform::TransformRewriter &rewriter,
+                                    transform::TransformResults &results,
+                                    transform::TransformState &state) {
+  auto matcher = SymbolTable::lookupNearestSymbolFrom<FunctionOpInterface>(
+      getOperation(), getMatcher());
+  if (matcher.isExternal()) {
+    return emitDefiniteFailure()
+           << "unresolved external symbol " << getMatcher();
+  }
+
+  SmallVector<SmallVector<MappedValue>, 2> rawResults;
+  rawResults.resize(getOperation()->getNumResults());
+  std::optional<DiagnosedSilenceableFailure> maybeFailure;
+  for (Operation *root : state.getPayloadOps(getRoot())) {
+    WalkResult walkResult = root->walk([&](Operation *op) {
+      DEBUG_MATCHER({
+        DBGS_MATCHER() << "matching ";
+        op->print(llvm::dbgs(),
+                  OpPrintingFlags().assumeVerified().skipRegions());
+        llvm::dbgs() << " @" << op << "\n";
+      });
+
+      // Try matching.
+      SmallVector<SmallVector<MappedValue>> mappings;
+      DiagnosedSilenceableFailure diag =
+          matchBlock(matcher.getFunctionBody().front(), op, state, mappings);
+      if (diag.isDefiniteFailure())
+        return WalkResult::interrupt();
+      if (diag.isSilenceableFailure()) {
+        DEBUG_MATCHER(DBGS_MATCHER() << "matcher " << matcher.getName()
+                                     << " failed: " << diag.getMessage());
+        return WalkResult::advance();
+      }
+
+      // If succeeded, collect results.
+      for (auto &&[i, mapping] : llvm::enumerate(mappings)) {
+        if (mapping.size() != 1) {
+          maybeFailure.emplace(emitSilenceableError()
+                               << "result #" << i << ", associated with "
+                               << mapping.size()
+                               << " payload objects, expected 1");
+          return WalkResult::interrupt();
+        }
+        rawResults[i].push_back(mapping[0]);
+      }
+      return WalkResult::advance();
+    });
+    if (walkResult.wasInterrupted())
+      return std::move(*maybeFailure);
+    assert(!maybeFailure && "failure set but the walk was not interrupted");
+
+    for (auto &&[opResult, rawResult] :
+         llvm::zip_equal(getOperation()->getResults(), rawResults)) {
+      results.setMappedValues(opResult, rawResult);
+    }
+  }
+  return DiagnosedSilenceableFailure::success();
+}
+
+void transform::CollectMatchingOp::getEffects(
+    SmallVectorImpl<MemoryEffects::EffectInstance> &effects) {
+  onlyReadsHandle(getRoot(), effects);
+  producesHandle(getResults(), effects);
+  onlyReadsPayload(effects);
+}
+
+LogicalResult transform::CollectMatchingOp::verifySymbolUses(
+    SymbolTableCollection &symbolTable) {
+  auto matcherSymbol = dyn_cast_or_null<FunctionOpInterface>(
+      symbolTable.lookupNearestSymbolFrom(getOperation(), getMatcher()));
+  if (!matcherSymbol ||
+      !isa<TransformOpInterface>(matcherSymbol.getOperation()))
+    return emitError() << "unresolved matcher symbol " << getMatcher();
+
+  ArrayRef<Type> argumentTypes = matcherSymbol.getArgumentTypes();
+  if (argumentTypes.size() != 1 ||
+      !isa<TransformHandleTypeInterface>(argumentTypes[0])) {
+    return emitError()
+           << "expected the matcher to take one operation handle argument";
+  }
+  if (!matcherSymbol.getArgAttr(
+          0, transform::TransformDialect::kArgReadOnlyAttrName)) {
+    return emitError() << "expected the matcher argument to be marked readonly";
+  }
+
+  ArrayRef<Type> resultTypes = matcherSymbol.getResultTypes();
+  if (resultTypes.size() != getOperation()->getNumResults()) {
+    return emitError()
+           << "expected the matcher to yield as many values as op has results ("
+           << getOperation()->getNumResults() << "), got "
+           << resultTypes.size();
+  }
+
+  for (auto &&[i, matcherType, resultType] :
+       llvm::enumerate(resultTypes, getOperation()->getResultTypes())) {
+    if (implementSameTransformInterface(matcherType, resultType))
+      continue;
+
+    return emitError()
+           << "mismatching type interfaces for matcher result and op result #"
+           << i;
+  }
+
+  return success();
+}
+
+//===----------------------------------------------------------------------===//
+// ForeachMatchOp
+//===----------------------------------------------------------------------===//
+
 DiagnosedSilenceableFailure
 transform::ForeachMatchOp::apply(transform::TransformRewriter &rewriter,
                                  transform::TransformResults &results,
@@ -978,22 +1110,6 @@ LogicalResult transform::ForeachMatchOp::verify() {
   return success();
 }
 
-/// Returns `true` if both types implement one of the interfaces provided as
-/// template parameters.
-template <typename... Tys>
-static bool implementSameInterface(Type t1, Type t2) {
-  return ((isa<Tys>(t1) && isa<Tys>(t2)) || ... || false);
-}
-
-/// Returns `true` if both types implement one of the transform dialect
-/// interfaces.
-static bool implementSameTransformInterface(Type t1, Type t2) {
-  return implementSameInterface<transform::TransformHandleTypeInterface,
-                                transform::TransformParamTypeInterface,
-                                transform::TransformValueHandleTypeInterface>(
-      t1, t2);
-}
-
 /// Checks that the attributes of the function-like operation have correct
 /// consumption effect annotations. If `alsoVerifyInternal`, checks for
 /// annotations being present even if they can be inferred from the body.

mlir/test/Dialect/Transform/ops-invalid.mlir

@@ -704,3 +704,71 @@ transform.sequence failures(propagate) {
   // expected-error @below {{expected the type of the parameter attribute ('i64') to match the parameter type ('i32')}}
   transform.num_associations %arg0 : (!transform.any_op) -> !transform.param<i32>
 }
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{unresolved matcher symbol @missing_symbol}}
+    transform.collect_matching @missing_symbol in %arg0 : (!transform.any_op) -> !transform.any_op
+    transform.yield
+  }
+}
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{expected the matcher to take one operation handle argument}}
+    transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_op
+    transform.yield
+  }
+
+  transform.named_sequence @matcher() {
+    transform.yield
+  }
+}
+
+// -----
+
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{expected the matcher argument to be marked readonly}}
+    transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_op
+    transform.yield
+  }
+
+  transform.named_sequence @matcher(%arg0: !transform.any_op) {
+    transform.yield
+  }
+}
+
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{expected the matcher to yield as many values as op has results (1), got 0}}
+    transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_op
+    transform.yield
+  }
+
+  transform.named_sequence @matcher(%arg0: !transform.any_op {transform.readonly}) {
+    transform.yield
+  }
+}
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{mismatching type interfaces for matcher result and op result #0}}
+    transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_value
+    transform.yield
+  }
+
+  transform.named_sequence @matcher(%arg0: !transform.any_op {transform.readonly}) -> !transform.any_op {
+    transform.yield %arg0 : !transform.any_op
+  }
+}

mlir/test/Dialect/Transform/test-interpreter.mlir

@@ -2380,3 +2380,47 @@ module @named_inclusion attributes { transform.with_named_sequence } {
     transform.yield
   }
 }
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{result #0, associated with 2 payload objects, expected 1}}
+    transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_op
+    transform.yield
+  }
+
+  transform.named_sequence @matcher(%arg0: !transform.any_op {transform.readonly}) -> !transform.any_op {
+    %0 = transform.merge_handles %arg0, %arg0 : !transform.any_op
+    transform.yield %0 : !transform.any_op
+  }
+}
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-error @below {{unresolved external symbol @matcher}}
+    transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_op
+    transform.yield
+  }
+
+  transform.named_sequence @matcher(%arg0: !transform.any_op {transform.readonly}) -> !transform.any_op
+}
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op) {
+    // expected-remark @below {{matched}}
+    %0 = transform.collect_matching @matcher in %arg0 : (!transform.any_op) -> !transform.any_op
+    // expected-remark @below {{matched}}
+    transform.test_print_remark_at_operand %0, "matched" : !transform.any_op
+    transform.yield
+  }
+
+  transform.named_sequence @matcher(%arg0: !transform.any_op {transform.readonly}) -> !transform.any_op {
+    transform.match.operation_name %arg0 ["transform.test_print_remark_at_operand", "transform.collect_matching"] : !transform.any_op
+    transform.yield %arg0 : !transform.any_op
+  }
+}