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/ADT/STLFunctionalExtras.h"
27#include "llvm/IR/PassManager.h"
28
29namespace llvm {
30class Function;
31struct MergedLoadStoreMotionOptions {
32 bool SplitFooterBB;
33 MergedLoadStoreMotionOptions(bool SplitFooterBB = false)
34 : SplitFooterBB(SplitFooterBB) {}
35
36 MergedLoadStoreMotionOptions &splitFooterBB(bool SFBB) {
37 SplitFooterBB = SFBB;
38 return *this;
39 }
40};
41
42class MergedLoadStoreMotionPass
43 : public PassInfoMixin<MergedLoadStoreMotionPass> {
44 MergedLoadStoreMotionOptions Options;
45
46public:
47 MergedLoadStoreMotionPass()
48 : MergedLoadStoreMotionPass(MergedLoadStoreMotionOptions()) {}
49 MergedLoadStoreMotionPass(const MergedLoadStoreMotionOptions &PassOptions)
50 : Options(PassOptions) {}
51 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
52 void printPipeline(raw_ostream &OS,
53 function_ref<StringRef(StringRef)> MapClassName2PassName);
54};
55}
56
57#endif // LLVM_TRANSFORMS_SCALAR_MERGEDLOADSTOREMOTION_H
58