| //===- ShardingInterface.cpp -------------------------------------*- C++-*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "mlir/Dialect/Mesh/Interfaces/ShardingInterface.h" |
| #include "mlir/Dialect/Mesh/IR/MeshOps.h" |
| #include "mlir/Dialect/Utils/IndexingUtils.h" |
| #include "mlir/IR/AffineMap.h" |
| #include "mlir/Support/LLVM.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/Support/Debug.h" |
| |
| #include <algorithm> |
| #include <utility> |
| |
| #define DEBUG_TYPE "sharding-interface" |
| #define DBGS() (llvm::dbgs() << "[" DEBUG_TYPE << "]: ") |
| |
| using namespace mlir; |
| using namespace mlir::mesh; |
| |
| #include "mlir/Dialect/Mesh/Interfaces/ShardingInterface.cpp.inc" |
| |
| //===----------------------------------------------------------------------===// |
| // common util functions |
| //===----------------------------------------------------------------------===// |
| |
| static LogicalResult |
| checkOperandAffineExprRecursively(AffineExpr expr, |
| SmallVectorImpl<bool> &seenIds) { |
| switch (expr.getKind()) { |
| case AffineExprKind::Add: { |
| auto binOpExpr = cast<AffineBinaryOpExpr>(expr); |
| AffineExpr lhs = binOpExpr.getLHS(); |
| AffineExpr rhs = binOpExpr.getRHS(); |
| if (failed(checkOperandAffineExprRecursively(lhs, seenIds))) |
| return failure(); |
| if (failed(checkOperandAffineExprRecursively(rhs, seenIds))) |
| return failure(); |
| return success(); |
| } |
| case AffineExprKind::Mul: { |
| auto binOpExpr = cast<AffineBinaryOpExpr>(expr); |
| AffineExpr lhs = binOpExpr.getLHS(); |
| AffineExpr rhs = binOpExpr.getRHS(); |
| AffineExpr dimExpr; |
| if (lhs.getKind() == AffineExprKind::DimId && |
| rhs.getKind() == AffineExprKind::Constant) { |
| dimExpr = lhs; |
| } else if (rhs.getKind() == AffineExprKind::DimId && |
| lhs.getKind() == AffineExprKind::Constant) { |
| dimExpr = rhs; |
| } else |
| return failure(); |
| unsigned position = cast<AffineDimExpr>(dimExpr).getPosition(); |
| if ((size_t)position >= seenIds.size() || seenIds[position]) |
| return failure(); |
| seenIds[position] = true; |
| return success(); |
| } |
| case AffineExprKind::DimId: { |
| unsigned position = cast<AffineDimExpr>(expr).getPosition(); |
| if ((size_t)position >= seenIds.size() || seenIds[position]) |
| return failure(); |
| seenIds[position] = true; |
| return success(); |
| } |
| default: |
| return failure(); |
| } |
| } |
| |
| static FailureOr<llvm::SmallSet<unsigned, 2>> |
| checkOperandAffineExpr(AffineExpr expr, unsigned numDims) { |
| SmallVector<bool> seenIds(numDims, false); |
| if (failed(checkOperandAffineExprRecursively(expr, seenIds))) |
| return failure(); |
| |
| llvm::SmallSet<unsigned, 2> positions; |
| for (auto it : llvm::enumerate(seenIds)) { |
| if (it.value()) |
| positions.insert((unsigned)it.index()); |
| } |
| return positions; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // mesh::getMeshShardingAttr |
| //===----------------------------------------------------------------------===// |
| |
| FailureOr<std::pair<bool, MeshShardingAttr>> |
| mesh::getMeshShardingAttr(OpResult result) { |
| Value val = result.cast<Value>(); |
| bool anyShardedForDef = llvm::any_of(val.getUsers(), [](Operation *user) { |
| auto shardOp = llvm::dyn_cast<mesh::ShardOp>(user); |
| if (!shardOp) |
| return false; |
| return !shardOp.getAnnotateForUsers(); |
| }); |
| |
| if (anyShardedForDef) { |
| // expected to have exact one use if it has a use of `mesh.shard` without |
| // unit attr annotate_for_users |
| if (!val.hasOneUse()) |
| return failure(); |
| auto shardOp = llvm::cast<mesh::ShardOp>(*val.getUsers().begin()); |
| return std::make_pair(false, shardOp.getShard()); |
| } |
| |
| bool anyShardedForUsers = llvm::any_of(val.getUsers(), [](Operation *user) { |
| auto shardOp = llvm::dyn_cast<mesh::ShardOp>(user); |
| if (!shardOp) |
| return false; |
| return shardOp.getAnnotateForUsers(); |
| }); |
| if (anyShardedForUsers) { |
| SmallVector<ShardOp> shardOps; |
| for (Operation *user : val.getUsers()) { |
| ShardOp shardOp = llvm::dyn_cast<ShardOp>(user); |
| if (shardOp) |
| shardOps.push_back(shardOp); |
| } |
| MeshShardingAttr shardForDef = shardOps[0].getShard(); |
| for (size_t i = 1; i < shardOps.size(); ++i) { |
| // TODO: Deduce a reasonable mesh sharding attr for def when they are |
| // different |
| assert(shardOps[i].getShard() == shardForDef && |
| "only support all shard ops have the same mesh sharding attr"); |
| } |
| return std::make_pair(true, shardForDef); |
| } |
| return failure(); |
| } |
| |
| FailureOr<std::pair<bool, MeshShardingAttr>> |
| mesh::getMeshShardingAttr(OpOperand &opOperand) { |
| Value val = opOperand.get(); |
| if (ShardOp shardOp = val.getDefiningOp<ShardOp>()) |
| return std::make_pair(shardOp.getAnnotateForUsers(), shardOp.getShard()); |
| |
| return failure(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // ShardingInterface::verifyShardingInterfaceImpl |
| //===----------------------------------------------------------------------===// |
| |
| LogicalResult mesh::ShardingInterface::verifyShardingInterfaceImpl() { |
| Operation *op = getOperation(); |
| |
| // check operands and results type |
| for (Type type : op->getOperandTypes()) |
| if (!llvm::isa<RankedTensorType>(type)) |
| return failure(); |
| for (Type type : op->getResultTypes()) |
| if (!llvm::isa<RankedTensorType>(type)) |
| return failure(); |
| |
| // check loop types |
| SmallVector<IteratorType> loopTypes = getLoopIteratorTypes(); |
| if (loopTypes.size() == 0) |
| return failure(); |
| |
| // check maps |
| SmallVector<AffineMap> maps = getIndexingMaps(); |
| if (maps.size() == 0) |
| return failure(); |
| unsigned numOperands = op->getNumOperands(); |
| unsigned numResults = op->getNumResults(); |
| if (numOperands + numResults != maps.size()) |
| return failure(); |
| |
| for (OpResult result : op->getResults()) { |
| auto resultType = result.getType().dyn_cast<RankedTensorType>(); |
| if (!resultType) |
| return failure(); |
| AffineMap map = maps[numOperands + result.getResultNumber()]; |
| if (!map.isProjectedPermutation()) { |
| return failure(); |
| } |
| } |
| |
| return success(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // ShardingInterface::printLoopTypesAndIndexingMaps |
| //===----------------------------------------------------------------------===// |
| |
| void mesh::ShardingInterface::printLoopTypesAndIndexingMaps(raw_ostream &os) { |
| os << "print loop types and indexing maps for: \n"; |
| getOperation()->print(os); |
| os << "\n"; |
| os << "loop types: ["; |
| for (IteratorType type : getLoopIteratorTypes()) { |
| os << stringifyEnum(type) << " "; |
| } |
| os << "]\n"; |
| os << "indexing maps: \n"; |
| for (AffineMap map : getIndexingMaps()) |
| os << map << "\n"; |
| os << "\n"; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // detail::defaultGetShardingOption |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| |
| // Update the given `shardingOption` according to `meshAxes` and `loopIdx` |
| static LogicalResult fillShardingOption(Operation *op, |
| ShardingOption &shardingOption, |
| FlatSymbolRefAttr cluster, |
| ArrayRef<MeshAxis> meshAxes, |
| unsigned loopIdx) { |
| if ((shardingOption.cluster && cluster && |
| shardingOption.cluster != cluster) || |
| (!shardingOption.shardingArray[loopIdx].empty() && |
| shardingOption.shardingArray[loopIdx] != meshAxes)) { |
| LLVM_DEBUG(DBGS() << "sharding option conflicts on loop iterator " |
| << loopIdx << "\n"); |
| return failure(); |
| } |
| for (size_t i = 0; i < shardingOption.shardingArray.size(); ++i) { |
| if (i == loopIdx) |
| continue; |
| |
| for (MeshAxis axis : meshAxes) { |
| if (llvm::is_contained(shardingOption.shardingArray[i], axis)) { |
| LLVM_DEBUG(DBGS() << "sharding option conflicts because mesh axes " |
| << axis << " duplicate"); |
| return failure(); |
| } |
| } |
| } |
| if (cluster) |
| shardingOption.cluster = cluster; |
| if (shardingOption.shardingArray[loopIdx].empty()) |
| shardingOption.shardingArray[loopIdx].append(meshAxes.begin(), |
| meshAxes.end()); |
| return success(); |
| } |
| |
| } // namespace |
| |
| FailureOr<ShardingOption> mesh::detail::defaultGetShardingOption( |
| Operation *op, ArrayRef<MeshShardingAttr> operandShardings, |
| ArrayRef<MeshShardingAttr> resultShardings) { |
| ShardingInterface shardingOp = llvm::cast<ShardingInterface>(op); |
| ShardingOption shardingOption; |
| |
| if (failed(shardingOp.verifyShardingInterfaceImpl())) |
| return op->emitOpError() << "invalid sharding interface implementation"; |
| SmallVector<IteratorType> loopTypes = shardingOp.getLoopIteratorTypes(); |
| SmallVector<AffineMap> maps = shardingOp.getIndexingMaps(); |
| unsigned numOperands = op->getNumOperands(); |
| shardingOption.shardingArray.resize(loopTypes.size()); |
| llvm::SmallVector<MeshAxis> partialMeshAxes; |
| Partial partialType; |
| llvm::SmallSet<unsigned, 4> visitedLoopIndices; |
| bool anyShardingInResultsOrOperands = false; |
| |
| // 1. Fill sharding option based on op results |
| for (auto shardingIt : llvm::enumerate(resultShardings)) { |
| MeshShardingAttr shardAttr = shardingIt.value(); |
| if (!shardAttr) |
| continue; |
| AffineMap map = maps[numOperands + shardingIt.index()]; |
| anyShardingInResultsOrOperands = true; |
| // Handle the split axes: calculate the corresponding loop index for each |
| // split axes sub-array, and then store the sub-array to |
| // shardingOption[index] |
| for (auto it : llvm::zip(map.getResults(), shardAttr.getSplitAxes())) { |
| AffineExpr expr = std::get<0>(it); |
| ArrayRef<MeshAxis> axes = std::get<1>(it).asArrayRef(); |
| auto dim = cast<AffineDimExpr>(expr); |
| unsigned index = dim.getPosition(); |
| visitedLoopIndices.insert(index); |
| if (failed(fillShardingOption(op, shardingOption, shardAttr.getCluster(), |
| axes, index))) |
| return failure(); |
| } |
| |
| // Handle the partial axes: at this stage, the exact loop index/indices |
| // cannot be decided because there could be multiple reduction loops. |
| ArrayRef<MeshAxis> partialAxes = shardAttr.getPartialAxes(); |
| if (!partialAxes.empty()) { |
| if (!partialMeshAxes.empty()) |
| return op->emitOpError() << "at most one result with partial axes is " |
| "supported at present"; |
| partialType = shardAttr.getPartialType(); |
| partialMeshAxes.append(partialAxes.begin(), partialAxes.end()); |
| // Add all the reduction loop indices to `visitedLoopIndices` if |
| // `partialAxes` is not empty |
| for (size_t loopIdx = 0; loopIdx < loopTypes.size(); ++loopIdx) { |
| if (isReductionLoop(loopTypes[loopIdx])) |
| visitedLoopIndices.insert(loopIdx); |
| } |
| } |
| } |
| |
| // 2. Fill sharding option based on operands |
| for (auto shardingIt : llvm::enumerate(operandShardings)) { |
| MeshShardingAttr shardAttr = shardingIt.value(); |
| if (!shardAttr) |
| continue; |
| |
| anyShardingInResultsOrOperands = true; |
| AffineMap map = maps[shardingIt.index()]; |
| unsigned numDims = map.getNumDims(); |
| |
| // Handle the split axes. Partial axes don't need to be handled because they |
| // only affect the defining op of the operand. |
| // |
| // TODO: Change to process the operands with single loop index first and |
| // then the operands with multiple loop indices. |
| for (auto it : llvm::zip(map.getResults(), shardAttr.getSplitAxes())) { |
| AffineExpr expr = std::get<0>(it); |
| ArrayRef<MeshAxis> axes = std::get<1>(it).asArrayRef(); |
| FailureOr<llvm::SmallSet<unsigned, 2>> loopIndices = |
| checkOperandAffineExpr(expr, numDims); |
| if (failed(loopIndices)) |
| return op->emitOpError() |
| << "operand's affine expression is restricted to const_i * " |
| "dim_i + const_j + dim_j + ..."; |
| if (loopIndices->empty()) |
| continue; |
| if (loopIndices->size() == 1) { |
| unsigned loopIdx = *loopIndices->begin(); |
| visitedLoopIndices.insert(loopIdx); |
| if (failed(fillShardingOption(op, shardingOption, |
| shardAttr.getCluster(), axes, loopIdx))) |
| return failure(); |
| } |
| // If multiple loop indices correspond to a dimension of an operand, it is |
| // difficult to infer which loop indices are responsible for sharding. |
| // Therefore, the exact loop index must be specified by others. |
| if (loopIndices->size() > 1) { |
| bool seenLoopIndices = false; |
| for (unsigned loopIdx : *loopIndices) { |
| if (visitedLoopIndices.contains(loopIdx)) { |
| seenLoopIndices = true; |
| break; |
| } |
| } |
| if (!seenLoopIndices) |
| return op->emitOpError() |
| << "the operand " << shardingIt.index() |
| << " has multiple loop indices in a dimension, but none of " |
| "them could be found in the exactly specified annotation " |
| "of op results or operands."; |
| } |
| } |
| } |
| |
| // 3. Finalize sharding option |
| if (!partialMeshAxes.empty()) { |
| bool anyNonEmptyReductionLoop = llvm::any_of( |
| llvm::enumerate(shardingOption.shardingArray), [&](auto it) { |
| SmallVector<MeshAxis> &subArray = it.value(); |
| int64_t idx = it.index(); |
| return isReductionLoop(loopTypes[idx]) && !subArray.empty(); |
| }); |
| if (!anyNonEmptyReductionLoop) { |
| bool filled = false; |
| for (size_t idx = 0; idx < loopTypes.size(); ++idx) { |
| if (isReductionLoop(loopTypes[idx]) && |
| areReductionAndPartialMatch(loopTypes[idx], partialType)) { |
| std::ignore = fillShardingOption(op, shardingOption, nullptr, |
| partialMeshAxes, idx); |
| filled = true; |
| break; |
| } |
| } |
| if (!filled) |
| return op->emitOpError() << "no matched reduction loop found for the " |
| "result's partial type"; |
| } |
| } |
| removeTrailingEmptySubArray(shardingOption.shardingArray); |
| if (!anyShardingInResultsOrOperands) |
| shardingOption.empty = true; |
| return shardingOption; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // detail::defaultAddShardingAnnotations |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| |
| // To add a `mesh.shard` op for the given result, based on the details provided |
| // in `shardingOption`, `map`, and `loopTypes`. |
| static LogicalResult addShardOp(OpBuilder &b, OpResult result, |
| const ShardingOption &shardingOption, |
| AffineMap map, |
| ArrayRef<IteratorType> loopTypes) { |
| FailureOr<std::pair<bool, MeshShardingAttr>> maybeSharding = |
| getMeshShardingAttr(result); |
| if (succeeded(maybeSharding) && !maybeSharding->first) |
| return success(); |
| |
| auto resultType = result.getType().cast<RankedTensorType>(); |
| SmallVector<SmallVector<MeshAxis>> splitAxes(resultType.getRank()); |
| SmallVector<MeshAxis> partialAxes; |
| |
| // process the split axes |
| for (auto it : llvm::enumerate(map.getResults())) { |
| AffineExpr expr = it.value(); |
| // `expr` must be an `AffineDimExpr` because `map` is verified by |
| // isProjectedPermutation |
| auto dim = cast<AffineDimExpr>(expr); |
| unsigned loopIdx = dim.getPosition(); |
| if (loopIdx < shardingOption.shardingArray.size()) |
| splitAxes[it.index()].append(shardingOption.shardingArray[loopIdx]); |
| } |
| |
| // process the partial axes |
| // partialType will be ignored if partialAxes is empty |
| Partial partialType = Partial::Sum; |
| for (auto it : llvm::zip(loopTypes, shardingOption.shardingArray)) { |
| IteratorType iType = std::get<0>(it); |
| if (isReductionLoop(iType)) { |
| Partial curPartialType = getPartialTypeFromReduction(iType); |
| if (!partialAxes.empty()) |
| assert(partialType == curPartialType && |
| "Only one reduction type is supported"); |
| partialType = curPartialType; |
| const SmallVector<MeshAxis> &axis = std::get<1>(it); |
| partialAxes.append(axis); |
| } |
| } |
| |
| removeTrailingEmptySubArray(splitAxes); |
| MeshShardingAttr shardAttr = |
| MeshShardingAttr::get(b.getContext(), shardingOption.cluster, splitAxes, |
| partialAxes, partialType); |
| OpBuilder::InsertionGuard guard(b); |
| b.setInsertionPointAfterValue(result); |
| auto shardOp = b.create<ShardOp>(result.getLoc(), resultType, result, |
| shardAttr, /*annotate_for_users*/ false); |
| result.replaceAllUsesExcept(shardOp, shardOp); |
| return success(); |
| } |
| |
| // To add a `mesh.shard` op for the given operand, based on the details provided |
| // in `shardingOption`, `map`, and `loopTypes`. |
| static LogicalResult addShardOp(OpBuilder &b, OpOperand &opOperand, |
| const ShardingOption &shardingOption, |
| AffineMap map, |
| ArrayRef<IteratorType> loopTypes) { |
| auto maybeShardingAttr = getMeshShardingAttr(opOperand); |
| if (succeeded(maybeShardingAttr) && maybeShardingAttr->first) |
| return success(); |
| Value operand = opOperand.get(); |
| auto operandType = operand.getType().cast<RankedTensorType>(); |
| SmallVector<SmallVector<MeshAxis>> splitAxes(operandType.getRank()); |
| unsigned numDims = map.getNumDims(); |
| for (auto it : llvm::enumerate(map.getResults())) { |
| int64_t idx = it.index(); |
| AffineExpr expr = it.value(); |
| FailureOr<llvm::SmallSet<unsigned, 2>> loopIndices = |
| checkOperandAffineExpr(expr, numDims); |
| if (failed(loopIndices)) |
| return failure(); |
| SmallVector<unsigned> shardedLoopIndices; |
| for (unsigned loopIdx : *loopIndices) { |
| if ((size_t)loopIdx < shardingOption.shardingArray.size() && |
| !shardingOption.shardingArray[loopIdx].empty()) |
| shardedLoopIndices.push_back(loopIdx); |
| } |
| // mostly one sharded loop index is accepted |
| if (shardedLoopIndices.size() > 1) |
| return failure(); |
| if (shardedLoopIndices.size() == 1) { |
| splitAxes[idx].append( |
| shardingOption.shardingArray[shardedLoopIndices[0]]); |
| } |
| } |
| |
| removeTrailingEmptySubArray(splitAxes); |
| MeshShardingAttr shardAttr = |
| MeshShardingAttr::get(b.getContext(), shardingOption.cluster, splitAxes); |
| OpBuilder::InsertionGuard guard(b); |
| b.setInsertionPoint(opOperand.getOwner()); |
| auto shardOp = b.create<ShardOp>(operand.getLoc(), operandType, operand, |
| shardAttr, true); |
| opOperand.set(shardOp); |
| |
| return success(); |
| } |
| |
| } // namespace |
| |
| LogicalResult mesh::detail::defaultAddShardingAnnotations( |
| Operation *op, OpBuilder &b, const ShardingOption &shardingOption) { |
| ShardingInterface shardingOp = llvm::cast<ShardingInterface>(op); |
| SmallVector<IteratorType> loopTypes = shardingOp.getLoopIteratorTypes(); |
| SmallVector<AffineMap> maps = shardingOp.getIndexingMaps(); |
| unsigned numOperands = op->getNumOperands(); |
| |
| // 1. add mesh.shard ops for all op results |
| for (OpResult result : op->getResults()) { |
| if (failed(addShardOp(b, result, shardingOption, |
| maps[numOperands + result.getResultNumber()], |
| loopTypes))) |
| return failure(); |
| } |
| |
| // 2. add mesh.shard ops for all operands |
| for (OpOperand &opOperand : op->getOpOperands()) { |
| if (failed(addShardOp(b, opOperand, shardingOption, |
| maps[opOperand.getOperandNumber()], loopTypes))) |
| return failure(); |
| } |
| |
| return success(); |
| } |
