diff --git a/mlir/include/mlir/Dialect/Vector/IR/VectorOps.td b/mlir/include/mlir/Dialect/Vector/IR/VectorOps.td index 85cc22ab3964a..aef156c5f1d05 100644 --- a/mlir/include/mlir/Dialect/Vector/IR/VectorOps.td +++ b/mlir/include/mlir/Dialect/Vector/IR/VectorOps.td @@ -836,6 +836,7 @@ def Vector_ToElementsOp : Vector_Op<"to_elements", [ let arguments = (ins AnyVectorOfAnyRank:$source); let results = (outs Variadic:$elements); let assemblyFormat = "$source attr-dict `:` type($source)"; + let hasFolder = 1; } def Vector_FromElementsOp : Vector_Op<"from_elements", [ @@ -873,6 +874,7 @@ def Vector_FromElementsOp : Vector_Op<"from_elements", [ let arguments = (ins Variadic:$elements); let results = (outs AnyFixedVectorOfAnyRank:$dest); let assemblyFormat = "$elements attr-dict `:` type($dest)"; + let hasFolder = 1; let hasCanonicalizer = 1; } diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp index e576eeac23656..6f0ac6bb58282 100644 --- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp +++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp @@ -2373,10 +2373,95 @@ std::optional> FMAOp::getShapeForUnroll() { return llvm::to_vector<4>(getVectorType().getShape()); } +//===----------------------------------------------------------------------===// +// ToElementsOp +//===----------------------------------------------------------------------===// + +/// Returns true if all the `operands` are defined by `defOp`. +/// Otherwise, returns false. +static bool haveSameDefiningOp(OperandRange operands, Operation *defOp) { + if (operands.empty()) + return false; + + return llvm::all_of(operands, [&](Value operand) { + Operation *currentDef = operand.getDefiningOp(); + return currentDef == defOp; + }); +} + +/// Folds vector.to_elements(vector.from_elements(%e0, %e1, ...)) into +/// (%e0, %e1, ...). For example: +/// +/// %0 = vector.from_elements %a, %b, %c : vector<3xf32> +/// %1:3 = vector.to_elements %0 : vector<3xf32> +/// user_op %1#0, %1#1, %1#2 +/// +/// becomes: +/// +/// user_op %a, %b, %c +/// +static LogicalResult +foldToElementsFromElements(ToElementsOp toElementsOp, + SmallVectorImpl &results) { + auto fromElementsOp = + toElementsOp.getSource().getDefiningOp(); + if (!fromElementsOp) + return failure(); + + llvm::append_range(results, fromElementsOp.getElements()); + return success(); +} + +LogicalResult ToElementsOp::fold(FoldAdaptor adaptor, + SmallVectorImpl &results) { + return foldToElementsFromElements(*this, results); +} + //===----------------------------------------------------------------------===// // FromElementsOp //===----------------------------------------------------------------------===// +/// Folds vector.from_elements(vector.to_elements(%vector)) into %vector. +/// +/// Case #1: Input and output vectors are the same. +/// +/// %0:3 = vector.to_elements %a : vector<3xf32> +/// %1 = vector.from_elements %0#0, %0#1, %0#2 : vector<3xf32> +/// user_op %1 +/// +/// becomes: +/// +/// user_op %a +/// +static OpFoldResult foldFromElementsToElements(FromElementsOp fromElementsOp) { + OperandRange fromElemsOperands = fromElementsOp.getElements(); + if (fromElemsOperands.empty()) + return {}; + + auto toElementsOp = fromElemsOperands[0].getDefiningOp(); + if (!toElementsOp) + return {}; + + if (!haveSameDefiningOp(fromElemsOperands, toElementsOp)) + return {}; + + // Case #1: Input and output vectors are the same. Forward the input vector. + Value toElementsInput = toElementsOp.getSource(); + if (fromElementsOp.getType() == toElementsInput.getType() && + llvm::equal(fromElemsOperands, toElementsOp.getResults())) { + return toElementsInput; + } + + // TODO: Support cases with different input and output shapes and different + // number of elements. + + return {}; +} + +OpFoldResult FromElementsOp::fold(FoldAdaptor adaptor) { + return foldFromElementsToElements(*this); +} + /// Rewrite a vector.from_elements into a vector.splat if all elements are the /// same SSA value. E.g.: /// diff --git a/mlir/test/Dialect/Vector/canonicalize.mlir b/mlir/test/Dialect/Vector/canonicalize.mlir index 6691cb52acdc0..65b73375831da 100644 --- a/mlir/test/Dialect/Vector/canonicalize.mlir +++ b/mlir/test/Dialect/Vector/canonicalize.mlir @@ -3023,6 +3023,58 @@ func.func @extract_from_0d_splat_broadcast_regression(%a: f32, %b: vector, // ----- +// CHECK-LABEL: func @to_elements_from_elements_no_op( +// CHECK-SAME: %[[A:.*]]: f32, %[[B:.*]]: f32 +func.func @to_elements_from_elements_no_op(%a: f32, %b: f32) -> (f32, f32) { + // CHECK-NOT: vector.from_elements + // CHECK-NOT: vector.to_elements + %0 = vector.from_elements %b, %a : vector<2xf32> + %1:2 = vector.to_elements %0 : vector<2xf32> + // CHECK: return %[[B]], %[[A]] + return %1#0, %1#1 : f32, f32 +} + +// ----- + +// CHECK-LABEL: func @from_elements_to_elements_no_op( +// CHECK-SAME: %[[A:.*]]: vector<4x2xf32> +func.func @from_elements_to_elements_no_op(%a: vector<4x2xf32>) -> vector<4x2xf32> { + // CHECK-NOT: vector.from_elements + // CHECK-NOT: vector.to_elements + %0:8 = vector.to_elements %a : vector<4x2xf32> + %1 = vector.from_elements %0#0, %0#1, %0#2, %0#3, %0#4, %0#5, %0#6, %0#7 : vector<4x2xf32> + // CHECK: return %[[A]] + return %1 : vector<4x2xf32> +} + +// ----- + +// CHECK-LABEL: func @from_elements_to_elements_dup_elems( +// CHECK-SAME: %[[A:.*]]: vector<4xf32> +func.func @from_elements_to_elements_dup_elems(%a: vector<4xf32>) -> vector<4x2xf32> { + // CHECK: %[[TO_EL:.*]]:4 = vector.to_elements %[[A]] + // CHECK: %[[FROM_EL:.*]] = vector.from_elements %[[TO_EL]]#0, %[[TO_EL]]#1, %[[TO_EL]]#2 + %0:4 = vector.to_elements %a : vector<4xf32> // 4 elements + %1 = vector.from_elements %0#0, %0#1, %0#2, %0#3, %0#0, %0#1, %0#2, %0#3 : vector<4x2xf32> + // CHECK: return %[[FROM_EL]] + return %1 : vector<4x2xf32> +} + +// ----- + +// CHECK-LABEL: func @from_elements_to_elements_shuffle( +// CHECK-SAME: %[[A:.*]]: vector<4x2xf32> +func.func @from_elements_to_elements_shuffle(%a: vector<4x2xf32>) -> vector<4x2xf32> { + // CHECK: %[[TO_EL:.*]]:8 = vector.to_elements %[[A]] + // CHECK: %[[FROM_EL:.*]] = vector.from_elements %[[TO_EL]]#7, %[[TO_EL]]#0, %[[TO_EL]]#6 + %0:8 = vector.to_elements %a : vector<4x2xf32> + %1 = vector.from_elements %0#7, %0#0, %0#6, %0#1, %0#5, %0#2, %0#4, %0#3 : vector<4x2xf32> + // CHECK: return %[[FROM_EL]] + return %1 : vector<4x2xf32> +} + +// ----- + // CHECK-LABEL: func @vector_insert_const_regression( // CHECK: llvm.mlir.undef // CHECK: vector.insert