1//===- MergedLoadStoreMotion.h - merge and hoist/sink load/stores ---------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9//! \file 10//! This pass performs merges of loads and stores on both sides of a 11// diamond (hammock). It hoists the loads and sinks the stores. 12// 13// The algorithm iteratively hoists two loads to the same address out of a 14// diamond (hammock) and merges them into a single load in the header. Similar 15// it sinks and merges two stores to the tail block (footer). The algorithm 16// iterates over the instructions of one side of the diamond and attempts to 17// find a matching load/store on the other side. It hoists / sinks when it 18// thinks it safe to do so. This optimization helps with eg. hiding load 19// latencies, triggering if-conversion, and reducing static code size. 20// 21//===----------------------------------------------------------------------===// 22 23#ifndef LLVM_TRANSFORMS_SCALAR_MERGEDLOADSTOREMOTION_H 24#define LLVM_TRANSFORMS_SCALAR_MERGEDLOADSTOREMOTION_H 25 26#include "llvm/IR/Module.h" 27#include "llvm/IR/PassManager.h" 28 29namespace llvm { 30struct MergedLoadStoreMotionOptions { 31 bool SplitFooterBB; 32 MergedLoadStoreMotionOptions(bool SplitFooterBB = false) 33 : SplitFooterBB(SplitFooterBB) {} 34 35 MergedLoadStoreMotionOptions &splitFooterBB(bool SFBB) { 36 SplitFooterBB = SFBB; 37 return *this; 38 } 39}; 40 41class MergedLoadStoreMotionPass 42 : public PassInfoMixin<MergedLoadStoreMotionPass> { 43 MergedLoadStoreMotionOptions Options; 44 45public: 46 MergedLoadStoreMotionPass() 47 : MergedLoadStoreMotionPass(MergedLoadStoreMotionOptions()) {} 48 MergedLoadStoreMotionPass(const MergedLoadStoreMotionOptions &PassOptions) 49 : Options(PassOptions) {} 50 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); 51}; 52} 53 54#endif // LLVM_TRANSFORMS_SCALAR_MERGEDLOADSTOREMOTION_H 55