================ @@ -0,0 +1,204 @@ +//===-- LLVMInsertChainFolder.cpp -----------------------------------------===// +// +// 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 "flang/Optimizer/CodeGen/LLVMInsertChainFolder.h" +#include "mlir/Dialect/LLVMIR/LLVMAttrs.h" +#include "mlir/Dialect/LLVMIR/LLVMDialect.h" +#include "mlir/IR/Builders.h" +#include "llvm/Support/Debug.h" + +#define DEBUG_TYPE "flang-insert-folder" + +#include <deque> + +namespace { +// Helper class to construct the attribute elements of an aggregate value being +// folded without creating a full mlir::Attribute representation for each step +// of the insert value chain, which would both be expensive in terms of +// compilation time and memory (since the intermediate Attribute would survive, +// unused, inside the mlir context). +class InsertChainBackwardFolder { + // Type for the current value of an element of the aggregate value being + // constructed by the insert chain. + // At any point of the insert chain, the value of an element is either: + // - nullptr: not yet known, the insert has not yet been seen. + // - an mlir::Attribute: the element is fully defined. + // - a nested InsertChainBackwardFolder: the element is itself an aggregate + // and its sub-elements have been partially defined (insert with mutliple + // indices have been seen). + + // The insertion folder assumes backward walk of the insert chain. Once an + // element or sub-element has been defined, it is not overriden by new + // insertions (last insert wins). + using InFlightValue = + llvm::PointerUnion<mlir::Attribute, InsertChainBackwardFolder *>; + +public: + InsertChainBackwardFolder( + mlir::Type type, std::deque<InsertChainBackwardFolder> *folderStorage) + : values(getNumElements(type), mlir::Attribute{}), + folderStorage{folderStorage}, type{type} {} + + /// Push + bool pushValue(mlir::Attribute val, llvm::ArrayRef<int64_t> at); + + mlir::Attribute finalize(mlir::Attribute defaultFieldValue); + +private: + static int64_t getNumElements(mlir::Type type) { + if (auto structTy = + llvm::dyn_cast_if_present<mlir::LLVM::LLVMStructType>(type)) + return structTy.getBody().size(); + if (auto arrayTy = + llvm::dyn_cast_if_present<mlir::LLVM::LLVMArrayType>(type)) + return arrayTy.getNumElements(); + return 0; + } + + static mlir::Type getSubElementType(mlir::Type type, int64_t field) { + if (auto arrayTy = + llvm::dyn_cast_if_present<mlir::LLVM::LLVMArrayType>(type)) + return arrayTy.getElementType(); + if (auto structTy = + llvm::dyn_cast_if_present<mlir::LLVM::LLVMStructType>(type)) + return structTy.getBody()[field]; + return {}; + } ---------------- ashermancinelli wrote:
What does a default-constructed `mlir::Type` indicate here? https://github.com/llvm/llvm-project/pull/140268 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
