From 2d50029f986da1fdc9cb88cd8a1070aa086dc6b6 Mon Sep 17 00:00:00 2001 From: Matthias Springer Date: Thu, 15 Aug 2024 11:33:37 +0200 Subject: [PATCH] [mlir][Transforms] Dialect conversion: Build unresolved materialization for replaced ops (#101514) When inserting an argument/source/target materialization, the dialect conversion framework first inserts a "dummy" `unrealized_conversion_cast` op (during the rewrite process) and then (in the "finialize" phase) replaces these cast ops with the IR generated by the type converter callback. This is the case for all materializations, except when ops are being replaced with values that have a different type. In that case, the dialect conversion currently directly emits a source materialization. This commit changes the implementation, such that a temporary `unrealized_conversion_cast` is also inserted in that case. This commit simplifies the code base: all materializations now happen in `legalizeUnresolvedMaterialization`. This commit makes it possible to decouple source/target/argument materializations from the dialect conversion (to reduce the complexity of the code base). Such materializations can then also be optional. This will be implemented in a follow-up commit. Depends on #101476. --------- Co-authored-by: Jakub Kuderski --- .../Transforms/Utils/DialectConversion.cpp | 126 +++++++----------- .../VectorToSPIRV/vector-to-spirv.mlir | 4 +- .../Transforms/finalizing-bufferize.mlir | 3 +- .../test-legalize-type-conversion.mlir | 11 +- 4 files changed, 57 insertions(+), 87 deletions(-) diff --git a/mlir/lib/Transforms/Utils/DialectConversion.cpp b/mlir/lib/Transforms/Utils/DialectConversion.cpp index 8f9b21b7ee1e5b9..11e593cebc09b3d 100644 --- a/mlir/lib/Transforms/Utils/DialectConversion.cpp +++ b/mlir/lib/Transforms/Utils/DialectConversion.cpp @@ -2348,6 +2348,12 @@ struct OperationConverter { legalizeConvertedArgumentTypes(ConversionPatternRewriter &rewriter, ConversionPatternRewriterImpl &rewriterImpl); + /// Legalize the types of converted op results. + LogicalResult legalizeConvertedOpResultTypes( + ConversionPatternRewriter &rewriter, + ConversionPatternRewriterImpl &rewriterImpl, + DenseMap> &inverseMapping); + /// Legalize any unresolved type materializations. LogicalResult legalizeUnresolvedMaterializations( ConversionPatternRewriter &rewriter, @@ -2359,14 +2365,6 @@ struct OperationConverter { legalizeErasedResult(Operation *op, OpResult result, ConversionPatternRewriterImpl &rewriterImpl); - /// Legalize an operation result that was replaced with a value of a different - /// type. - LogicalResult legalizeChangedResultType( - Operation *op, OpResult result, Value newValue, - const TypeConverter *replConverter, ConversionPatternRewriter &rewriter, - ConversionPatternRewriterImpl &rewriterImpl, - const DenseMap> &inverseMapping); - /// Dialect conversion configuration. ConversionConfig config; @@ -2459,10 +2457,42 @@ OperationConverter::finalize(ConversionPatternRewriter &rewriter) { return failure(); DenseMap> inverseMapping = rewriterImpl.mapping.getInverse(); + if (failed(legalizeConvertedOpResultTypes(rewriter, rewriterImpl, + inverseMapping))) + return failure(); if (failed(legalizeUnresolvedMaterializations(rewriter, rewriterImpl, inverseMapping))) return failure(); + return success(); +} + +/// Finds a user of the given value, or of any other value that the given value +/// replaced, that was not replaced in the conversion process. +static Operation *findLiveUserOfReplaced( + Value initialValue, ConversionPatternRewriterImpl &rewriterImpl, + const DenseMap> &inverseMapping) { + SmallVector worklist = {initialValue}; + while (!worklist.empty()) { + Value value = worklist.pop_back_val(); + + // Walk the users of this value to see if there are any live users that + // weren't replaced during conversion. + auto liveUserIt = llvm::find_if_not(value.getUsers(), [&](Operation *user) { + return rewriterImpl.isOpIgnored(user); + }); + if (liveUserIt != value.user_end()) + return *liveUserIt; + auto mapIt = inverseMapping.find(value); + if (mapIt != inverseMapping.end()) + worklist.append(mapIt->second); + } + return nullptr; +} +LogicalResult OperationConverter::legalizeConvertedOpResultTypes( + ConversionPatternRewriter &rewriter, + ConversionPatternRewriterImpl &rewriterImpl, + DenseMap> &inverseMapping) { // Process requested operation replacements. for (unsigned i = 0; i < rewriterImpl.rewrites.size(); ++i) { auto *opReplacement = @@ -2485,14 +2515,21 @@ OperationConverter::finalize(ConversionPatternRewriter &rewriter) { if (result.getType() == newValue.getType()) continue; + Operation *liveUser = + findLiveUserOfReplaced(result, rewriterImpl, inverseMapping); + if (!liveUser) + continue; + // Legalize this result. - rewriter.setInsertionPoint(op); - if (failed(legalizeChangedResultType( - op, result, newValue, opReplacement->getConverter(), rewriter, - rewriterImpl, inverseMapping))) - return failure(); + Value castValue = rewriterImpl.buildUnresolvedMaterialization( + MaterializationKind::Source, computeInsertPoint(result), op->getLoc(), + /*inputs=*/newValue, /*outputType=*/result.getType(), + opReplacement->getConverter()); + rewriterImpl.mapping.map(result, castValue); + inverseMapping[castValue].push_back(result); } } + return success(); } @@ -2502,7 +2539,7 @@ LogicalResult OperationConverter::legalizeConvertedArgumentTypes( // Functor used to check if all users of a value will be dead after // conversion. // TODO: This should probably query the inverse mapping, same as in - // `legalizeChangedResultType`. + // `legalizeConvertedOpResultTypes`. auto findLiveUser = [&](Value val) { auto liveUserIt = llvm::find_if_not(val.getUsers(), [&](Operation *user) { return rewriterImpl.isOpIgnored(user); @@ -2832,67 +2869,6 @@ LogicalResult OperationConverter::legalizeErasedResult( return success(); } -/// Finds a user of the given value, or of any other value that the given value -/// replaced, that was not replaced in the conversion process. -static Operation *findLiveUserOfReplaced( - Value initialValue, ConversionPatternRewriterImpl &rewriterImpl, - const DenseMap> &inverseMapping) { - SmallVector worklist(1, initialValue); - while (!worklist.empty()) { - Value value = worklist.pop_back_val(); - - // Walk the users of this value to see if there are any live users that - // weren't replaced during conversion. - auto liveUserIt = llvm::find_if_not(value.getUsers(), [&](Operation *user) { - return rewriterImpl.isOpIgnored(user); - }); - if (liveUserIt != value.user_end()) - return *liveUserIt; - auto mapIt = inverseMapping.find(value); - if (mapIt != inverseMapping.end()) - worklist.append(mapIt->second); - } - return nullptr; -} - -LogicalResult OperationConverter::legalizeChangedResultType( - Operation *op, OpResult result, Value newValue, - const TypeConverter *replConverter, ConversionPatternRewriter &rewriter, - ConversionPatternRewriterImpl &rewriterImpl, - const DenseMap> &inverseMapping) { - Operation *liveUser = - findLiveUserOfReplaced(result, rewriterImpl, inverseMapping); - if (!liveUser) - return success(); - - // Functor used to emit a conversion error for a failed materialization. - auto emitConversionError = [&] { - InFlightDiagnostic diag = op->emitError() - << "failed to materialize conversion for result #" - << result.getResultNumber() << " of operation '" - << op->getName() - << "' that remained live after conversion"; - diag.attachNote(liveUser->getLoc()) - << "see existing live user here: " << *liveUser; - return failure(); - }; - - // If the replacement has a type converter, attempt to materialize a - // conversion back to the original type. - if (!replConverter) - return emitConversionError(); - - // Materialize a conversion for this live result value. - Type resultType = result.getType(); - Value convertedValue = replConverter->materializeSourceConversion( - rewriter, op->getLoc(), resultType, newValue); - if (!convertedValue) - return emitConversionError(); - - rewriterImpl.mapping.map(result, convertedValue); - return success(); -} - //===----------------------------------------------------------------------===// // Type Conversion //===----------------------------------------------------------------------===// diff --git a/mlir/test/Conversion/VectorToSPIRV/vector-to-spirv.mlir b/mlir/test/Conversion/VectorToSPIRV/vector-to-spirv.mlir index dd0ed77470a259b..d8570bdaf4247ff 100644 --- a/mlir/test/Conversion/VectorToSPIRV/vector-to-spirv.mlir +++ b/mlir/test/Conversion/VectorToSPIRV/vector-to-spirv.mlir @@ -560,8 +560,8 @@ func.func @deinterleave(%a: vector<4xf32>) -> (vector<2xf32>, vector<2xf32>) { // CHECK-SAME: (%[[ARG0:.+]]: vector<2xf32>) // CHECK: %[[EXTRACT0:.*]] = spirv.CompositeExtract %[[ARG0]][0 : i32] : vector<2xf32> // CHECK: %[[EXTRACT1:.*]] = spirv.CompositeExtract %[[ARG0]][1 : i32] : vector<2xf32> -// CHECK: %[[CAST0:.*]] = builtin.unrealized_conversion_cast %[[EXTRACT0]] : f32 to vector<1xf32> -// CHECK: %[[CAST1:.*]] = builtin.unrealized_conversion_cast %[[EXTRACT1]] : f32 to vector<1xf32> +// CHECK-DAG: %[[CAST0:.*]] = builtin.unrealized_conversion_cast %[[EXTRACT0]] : f32 to vector<1xf32> +// CHECK-DAG: %[[CAST1:.*]] = builtin.unrealized_conversion_cast %[[EXTRACT1]] : f32 to vector<1xf32> // CHECK: return %[[CAST0]], %[[CAST1]] func.func @deinterleave_scalar(%a: vector<2xf32>) -> (vector<1xf32>, vector<1xf32>) { %0, %1 = vector.deinterleave %a: vector<2xf32> -> vector<1xf32> diff --git a/mlir/test/Dialect/Bufferization/Transforms/finalizing-bufferize.mlir b/mlir/test/Dialect/Bufferization/Transforms/finalizing-bufferize.mlir index ff94c1b331d9281..a192434c5accf80 100644 --- a/mlir/test/Dialect/Bufferization/Transforms/finalizing-bufferize.mlir +++ b/mlir/test/Dialect/Bufferization/Transforms/finalizing-bufferize.mlir @@ -78,9 +78,8 @@ func.func @static_layout_to_no_layout_cast(%m: memref) -> memref> { %0 = bufferization.to_tensor %m : memref - // expected-error @+1 {{failed to materialize conversion for result #0 of operation 'bufferization.to_memref' that remained live after conversion}} + // expected-error @+1 {{failed to legalize unresolved materialization from ('memref') to 'memref>' that remained live after conversion}} %1 = bufferization.to_memref %0 : memref> - // expected-note @+1 {{see existing live user here}} return %1 : memref> } diff --git a/mlir/test/Transforms/test-legalize-type-conversion.mlir b/mlir/test/Transforms/test-legalize-type-conversion.mlir index d0563fed8e5d940..252b990210a1809 100644 --- a/mlir/test/Transforms/test-legalize-type-conversion.mlir +++ b/mlir/test/Transforms/test-legalize-type-conversion.mlir @@ -20,20 +20,16 @@ func.func @test_valid_arg_materialization(%arg0: i64) { // ----- func.func @test_invalid_result_materialization() { - // expected-error@below {{failed to materialize conversion for result #0 of operation 'test.type_producer' that remained live after conversion}} + // expected-error@below {{failed to legalize unresolved materialization from ('f64') to 'f16' that remained live after conversion}} %result = "test.type_producer"() : () -> f16 - - // expected-note@below {{see existing live user here}} "foo.return"(%result) : (f16) -> () } // ----- func.func @test_invalid_result_materialization() { - // expected-error@below {{failed to materialize conversion for result #0 of operation 'test.type_producer' that remained live after conversion}} + // expected-error@below {{failed to legalize unresolved materialization from ('f64') to 'f16' that remained live after conversion}} %result = "test.type_producer"() : () -> f16 - - // expected-note@below {{see existing live user here}} "foo.return"(%result) : (f16) -> () } @@ -51,9 +47,8 @@ func.func @test_transitive_use_materialization() { // ----- func.func @test_transitive_use_invalid_materialization() { - // expected-error@below {{failed to materialize conversion for result #0 of operation 'test.type_producer' that remained live after conversion}} + // expected-error@below {{failed to legalize unresolved materialization from ('f64') to 'f16' that remained live after conversion}} %result = "test.another_type_producer"() : () -> f16 - // expected-note@below {{see existing live user here}} "foo.return"(%result) : (f16) -> () }