| //===- Pattern.cpp - Conversion pattern to the LLVM dialect ---------------===// |
| // |
| // 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/Conversion/LLVMCommon/Pattern.h" |
| #include "mlir/Dialect/LLVMIR/FunctionCallUtils.h" |
| #include "mlir/Dialect/LLVMIR/LLVMDialect.h" |
| #include "mlir/Dialect/LLVMIR/LLVMTypes.h" |
| #include "mlir/IR/AffineMap.h" |
| #include "mlir/IR/BuiltinAttributes.h" |
| |
| using namespace mlir; |
| |
| //===----------------------------------------------------------------------===// |
| // ConvertToLLVMPattern |
| //===----------------------------------------------------------------------===// |
| |
| ConvertToLLVMPattern::ConvertToLLVMPattern( |
| StringRef rootOpName, MLIRContext *context, |
| const LLVMTypeConverter &typeConverter, PatternBenefit benefit) |
| : ConversionPattern(typeConverter, rootOpName, benefit, context) {} |
| |
| const LLVMTypeConverter *ConvertToLLVMPattern::getTypeConverter() const { |
| return static_cast<const LLVMTypeConverter *>( |
| ConversionPattern::getTypeConverter()); |
| } |
| |
| LLVM::LLVMDialect &ConvertToLLVMPattern::getDialect() const { |
| return *getTypeConverter()->getDialect(); |
| } |
| |
| Type ConvertToLLVMPattern::getIndexType() const { |
| return getTypeConverter()->getIndexType(); |
| } |
| |
| Type ConvertToLLVMPattern::getIntPtrType(unsigned addressSpace) const { |
| return IntegerType::get(&getTypeConverter()->getContext(), |
| getTypeConverter()->getPointerBitwidth(addressSpace)); |
| } |
| |
| Type ConvertToLLVMPattern::getVoidType() const { |
| return LLVM::LLVMVoidType::get(&getTypeConverter()->getContext()); |
| } |
| |
| Type ConvertToLLVMPattern::getVoidPtrType() const { |
| return LLVM::LLVMPointerType::get(&getTypeConverter()->getContext()); |
| } |
| |
| Value ConvertToLLVMPattern::createIndexAttrConstant(OpBuilder &builder, |
| Location loc, |
| Type resultType, |
| int64_t value) { |
| return builder.create<LLVM::ConstantOp>(loc, resultType, |
| builder.getIndexAttr(value)); |
| } |
| |
| Value ConvertToLLVMPattern::getStridedElementPtr( |
| Location loc, MemRefType type, Value memRefDesc, ValueRange indices, |
| ConversionPatternRewriter &rewriter) const { |
| |
| auto [strides, offset] = getStridesAndOffset(type); |
| |
| MemRefDescriptor memRefDescriptor(memRefDesc); |
| // Use a canonical representation of the start address so that later |
| // optimizations have a longer sequence of instructions to CSE. |
| // If we don't do that we would sprinkle the memref.offset in various |
| // position of the different address computations. |
| Value base = |
| memRefDescriptor.bufferPtr(rewriter, loc, *getTypeConverter(), type); |
| |
| Type indexType = getIndexType(); |
| Value index; |
| for (int i = 0, e = indices.size(); i < e; ++i) { |
| Value increment = indices[i]; |
| if (strides[i] != 1) { // Skip if stride is 1. |
| Value stride = |
| ShapedType::isDynamic(strides[i]) |
| ? memRefDescriptor.stride(rewriter, loc, i) |
| : createIndexAttrConstant(rewriter, loc, indexType, strides[i]); |
| increment = rewriter.create<LLVM::MulOp>(loc, increment, stride); |
| } |
| index = |
| index ? rewriter.create<LLVM::AddOp>(loc, index, increment) : increment; |
| } |
| |
| Type elementPtrType = memRefDescriptor.getElementPtrType(); |
| return index ? rewriter.create<LLVM::GEPOp>( |
| loc, elementPtrType, |
| getTypeConverter()->convertType(type.getElementType()), |
| base, index) |
| : base; |
| } |
| |
| // Check if the MemRefType `type` is supported by the lowering. We currently |
| // only support memrefs with identity maps. |
| bool ConvertToLLVMPattern::isConvertibleAndHasIdentityMaps( |
| MemRefType type) const { |
| if (!typeConverter->convertType(type.getElementType())) |
| return false; |
| return type.getLayout().isIdentity(); |
| } |
| |
| Type ConvertToLLVMPattern::getElementPtrType(MemRefType type) const { |
| auto addressSpace = getTypeConverter()->getMemRefAddressSpace(type); |
| if (failed(addressSpace)) |
| return {}; |
| return LLVM::LLVMPointerType::get(type.getContext(), *addressSpace); |
| } |
| |
| void ConvertToLLVMPattern::getMemRefDescriptorSizes( |
| Location loc, MemRefType memRefType, ValueRange dynamicSizes, |
| ConversionPatternRewriter &rewriter, SmallVectorImpl<Value> &sizes, |
| SmallVectorImpl<Value> &strides, Value &size, bool sizeInBytes) const { |
| assert(isConvertibleAndHasIdentityMaps(memRefType) && |
| "layout maps must have been normalized away"); |
| assert(count(memRefType.getShape(), ShapedType::kDynamic) == |
| static_cast<ssize_t>(dynamicSizes.size()) && |
| "dynamicSizes size doesn't match dynamic sizes count in memref shape"); |
| |
| sizes.reserve(memRefType.getRank()); |
| unsigned dynamicIndex = 0; |
| Type indexType = getIndexType(); |
| for (int64_t size : memRefType.getShape()) { |
| sizes.push_back( |
| size == ShapedType::kDynamic |
| ? dynamicSizes[dynamicIndex++] |
| : createIndexAttrConstant(rewriter, loc, indexType, size)); |
| } |
| |
| // Strides: iterate sizes in reverse order and multiply. |
| int64_t stride = 1; |
| Value runningStride = createIndexAttrConstant(rewriter, loc, indexType, 1); |
| strides.resize(memRefType.getRank()); |
| for (auto i = memRefType.getRank(); i-- > 0;) { |
| strides[i] = runningStride; |
| |
| int64_t staticSize = memRefType.getShape()[i]; |
| if (staticSize == 0) |
| continue; |
| bool useSizeAsStride = stride == 1; |
| if (staticSize == ShapedType::kDynamic) |
| stride = ShapedType::kDynamic; |
| if (stride != ShapedType::kDynamic) |
| stride *= staticSize; |
| |
| if (useSizeAsStride) |
| runningStride = sizes[i]; |
| else if (stride == ShapedType::kDynamic) |
| runningStride = |
| rewriter.create<LLVM::MulOp>(loc, runningStride, sizes[i]); |
| else |
| runningStride = createIndexAttrConstant(rewriter, loc, indexType, stride); |
| } |
| if (sizeInBytes) { |
| // Buffer size in bytes. |
| Type elementType = typeConverter->convertType(memRefType.getElementType()); |
| auto elementPtrType = LLVM::LLVMPointerType::get(rewriter.getContext()); |
| Value nullPtr = rewriter.create<LLVM::ZeroOp>(loc, elementPtrType); |
| Value gepPtr = rewriter.create<LLVM::GEPOp>( |
| loc, elementPtrType, elementType, nullPtr, runningStride); |
| size = rewriter.create<LLVM::PtrToIntOp>(loc, getIndexType(), gepPtr); |
| } else { |
| size = runningStride; |
| } |
| } |
| |
| Value ConvertToLLVMPattern::getSizeInBytes( |
| Location loc, Type type, ConversionPatternRewriter &rewriter) const { |
| // Compute the size of an individual element. This emits the MLIR equivalent |
| // of the following sizeof(...) implementation in LLVM IR: |
| // %0 = getelementptr %elementType* null, %indexType 1 |
| // %1 = ptrtoint %elementType* %0 to %indexType |
| // which is a common pattern of getting the size of a type in bytes. |
| Type llvmType = typeConverter->convertType(type); |
| auto convertedPtrType = LLVM::LLVMPointerType::get(rewriter.getContext()); |
| auto nullPtr = rewriter.create<LLVM::ZeroOp>(loc, convertedPtrType); |
| auto gep = rewriter.create<LLVM::GEPOp>(loc, convertedPtrType, llvmType, |
| nullPtr, ArrayRef<LLVM::GEPArg>{1}); |
| return rewriter.create<LLVM::PtrToIntOp>(loc, getIndexType(), gep); |
| } |
| |
| Value ConvertToLLVMPattern::getNumElements( |
| Location loc, MemRefType memRefType, ValueRange dynamicSizes, |
| ConversionPatternRewriter &rewriter) const { |
| assert(count(memRefType.getShape(), ShapedType::kDynamic) == |
| static_cast<ssize_t>(dynamicSizes.size()) && |
| "dynamicSizes size doesn't match dynamic sizes count in memref shape"); |
| |
| Type indexType = getIndexType(); |
| Value numElements = memRefType.getRank() == 0 |
| ? createIndexAttrConstant(rewriter, loc, indexType, 1) |
| : nullptr; |
| unsigned dynamicIndex = 0; |
| |
| // Compute the total number of memref elements. |
| for (int64_t staticSize : memRefType.getShape()) { |
| if (numElements) { |
| Value size = |
| staticSize == ShapedType::kDynamic |
| ? dynamicSizes[dynamicIndex++] |
| : createIndexAttrConstant(rewriter, loc, indexType, staticSize); |
| numElements = rewriter.create<LLVM::MulOp>(loc, numElements, size); |
| } else { |
| numElements = |
| staticSize == ShapedType::kDynamic |
| ? dynamicSizes[dynamicIndex++] |
| : createIndexAttrConstant(rewriter, loc, indexType, staticSize); |
| } |
| } |
| return numElements; |
| } |
| |
| /// Creates and populates the memref descriptor struct given all its fields. |
| MemRefDescriptor ConvertToLLVMPattern::createMemRefDescriptor( |
| Location loc, MemRefType memRefType, Value allocatedPtr, Value alignedPtr, |
| ArrayRef<Value> sizes, ArrayRef<Value> strides, |
| ConversionPatternRewriter &rewriter) const { |
| auto structType = typeConverter->convertType(memRefType); |
| auto memRefDescriptor = MemRefDescriptor::undef(rewriter, loc, structType); |
| |
| // Field 1: Allocated pointer, used for malloc/free. |
| memRefDescriptor.setAllocatedPtr(rewriter, loc, allocatedPtr); |
| |
| // Field 2: Actual aligned pointer to payload. |
| memRefDescriptor.setAlignedPtr(rewriter, loc, alignedPtr); |
| |
| // Field 3: Offset in aligned pointer. |
| Type indexType = getIndexType(); |
| memRefDescriptor.setOffset( |
| rewriter, loc, createIndexAttrConstant(rewriter, loc, indexType, 0)); |
| |
| // Fields 4: Sizes. |
| for (const auto &en : llvm::enumerate(sizes)) |
| memRefDescriptor.setSize(rewriter, loc, en.index(), en.value()); |
| |
| // Field 5: Strides. |
| for (const auto &en : llvm::enumerate(strides)) |
| memRefDescriptor.setStride(rewriter, loc, en.index(), en.value()); |
| |
| return memRefDescriptor; |
| } |
| |
| LogicalResult ConvertToLLVMPattern::copyUnrankedDescriptors( |
| OpBuilder &builder, Location loc, TypeRange origTypes, |
| SmallVectorImpl<Value> &operands, bool toDynamic) const { |
| assert(origTypes.size() == operands.size() && |
| "expected as may original types as operands"); |
| |
| // Find operands of unranked memref type and store them. |
| SmallVector<UnrankedMemRefDescriptor> unrankedMemrefs; |
| SmallVector<unsigned> unrankedAddressSpaces; |
| for (unsigned i = 0, e = operands.size(); i < e; ++i) { |
| if (auto memRefType = dyn_cast<UnrankedMemRefType>(origTypes[i])) { |
| unrankedMemrefs.emplace_back(operands[i]); |
| FailureOr<unsigned> addressSpace = |
| getTypeConverter()->getMemRefAddressSpace(memRefType); |
| if (failed(addressSpace)) |
| return failure(); |
| unrankedAddressSpaces.emplace_back(*addressSpace); |
| } |
| } |
| |
| if (unrankedMemrefs.empty()) |
| return success(); |
| |
| // Compute allocation sizes. |
| SmallVector<Value> sizes; |
| UnrankedMemRefDescriptor::computeSizes(builder, loc, *getTypeConverter(), |
| unrankedMemrefs, unrankedAddressSpaces, |
| sizes); |
| |
| // Get frequently used types. |
| Type indexType = getTypeConverter()->getIndexType(); |
| |
| // Find the malloc and free, or declare them if necessary. |
| auto module = builder.getInsertionPoint()->getParentOfType<ModuleOp>(); |
| LLVM::LLVMFuncOp freeFunc, mallocFunc; |
| if (toDynamic) |
| mallocFunc = LLVM::lookupOrCreateMallocFn(module, indexType); |
| if (!toDynamic) |
| freeFunc = LLVM::lookupOrCreateFreeFn(module); |
| |
| unsigned unrankedMemrefPos = 0; |
| for (unsigned i = 0, e = operands.size(); i < e; ++i) { |
| Type type = origTypes[i]; |
| if (!isa<UnrankedMemRefType>(type)) |
| continue; |
| Value allocationSize = sizes[unrankedMemrefPos++]; |
| UnrankedMemRefDescriptor desc(operands[i]); |
| |
| // Allocate memory, copy, and free the source if necessary. |
| Value memory = |
| toDynamic |
| ? builder.create<LLVM::CallOp>(loc, mallocFunc, allocationSize) |
| .getResult() |
| : builder.create<LLVM::AllocaOp>(loc, getVoidPtrType(), |
| IntegerType::get(getContext(), 8), |
| allocationSize, |
| /*alignment=*/0); |
| Value source = desc.memRefDescPtr(builder, loc); |
| builder.create<LLVM::MemcpyOp>(loc, memory, source, allocationSize, false); |
| if (!toDynamic) |
| builder.create<LLVM::CallOp>(loc, freeFunc, source); |
| |
| // Create a new descriptor. The same descriptor can be returned multiple |
| // times, attempting to modify its pointer can lead to memory leaks |
| // (allocated twice and overwritten) or double frees (the caller does not |
| // know if the descriptor points to the same memory). |
| Type descriptorType = getTypeConverter()->convertType(type); |
| if (!descriptorType) |
| return failure(); |
| auto updatedDesc = |
| UnrankedMemRefDescriptor::undef(builder, loc, descriptorType); |
| Value rank = desc.rank(builder, loc); |
| updatedDesc.setRank(builder, loc, rank); |
| updatedDesc.setMemRefDescPtr(builder, loc, memory); |
| |
| operands[i] = updatedDesc; |
| } |
| |
| return success(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Detail methods |
| //===----------------------------------------------------------------------===// |
| |
| /// Replaces the given operation "op" with a new operation of type "targetOp" |
| /// and given operands. |
| LogicalResult |
| LLVM::detail::oneToOneRewrite(Operation *op, StringRef targetOp, |
| ValueRange operands, |
| ArrayRef<NamedAttribute> targetAttrs, |
| const LLVMTypeConverter &typeConverter, |
| ConversionPatternRewriter &rewriter) { |
| unsigned numResults = op->getNumResults(); |
| |
| SmallVector<Type> resultTypes; |
| if (numResults != 0) { |
| resultTypes.push_back( |
| typeConverter.packOperationResults(op->getResultTypes())); |
| if (!resultTypes.back()) |
| return failure(); |
| } |
| |
| // Create the operation through state since we don't know its C++ type. |
| Operation *newOp = |
| rewriter.create(op->getLoc(), rewriter.getStringAttr(targetOp), operands, |
| resultTypes, targetAttrs); |
| |
| // If the operation produced 0 or 1 result, return them immediately. |
| if (numResults == 0) |
| return rewriter.eraseOp(op), success(); |
| if (numResults == 1) |
| return rewriter.replaceOp(op, newOp->getResult(0)), success(); |
| |
| // Otherwise, it had been converted to an operation producing a structure. |
| // Extract individual results from the structure and return them as list. |
| SmallVector<Value, 4> results; |
| results.reserve(numResults); |
| for (unsigned i = 0; i < numResults; ++i) { |
| results.push_back(rewriter.create<LLVM::ExtractValueOp>( |
| op->getLoc(), newOp->getResult(0), i)); |
| } |
| rewriter.replaceOp(op, results); |
| return success(); |
| } |
