1//===- AssumeBundleBuilder.h - utils to build assume bundles ----*- C++ -*-===//
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// This file contain tools to preserve informations. They should be used before
10// performing a transformation that may move and delete instructions as those
11// transformation may destroy or worsen information that can be derived from the
12// IR.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_TRANSFORMS_UTILS_ASSUMEBUNDLEBUILDER_H
17#define LLVM_TRANSFORMS_UTILS_ASSUMEBUNDLEBUILDER_H
18
19#include "llvm/Analysis/AssumeBundleQueries.h"
20#include "llvm/IR/Attributes.h"
21#include "llvm/IR/Instruction.h"
22#include "llvm/IR/PassManager.h"
23
24namespace llvm {
25class IntrinsicInst;
26class AssumptionCache;
27class DominatorTree;
28
29/// Build a call to llvm.assume to preserve informations that can be derived
30/// from the given instruction.
31/// If no information derived from \p I, this call returns null.
32/// The returned instruction is not inserted anywhere.
33AssumeInst *buildAssumeFromInst(Instruction *I);
34
35/// Calls BuildAssumeFromInst and if the resulting llvm.assume is valid insert
36/// if before I. This is usually what need to be done to salvage the knowledge
37/// contained in the instruction I.
38/// The AssumptionCache must be provided if it is available or the cache may
39/// become silently be invalid.
40/// The DominatorTree can optionally be provided to enable cross-block
41/// reasoning.
42void salvageKnowledge(Instruction *I, AssumptionCache *AC = nullptr,
43 DominatorTree *DT = nullptr);
44
45/// Build and return a new assume created from the provided knowledge
46/// if the knowledge in the assume is fully redundant this will return nullptr
47AssumeInst *buildAssumeFromKnowledge(ArrayRef<RetainedKnowledge> Knowledge,
48 Instruction *CtxI,
49 AssumptionCache *AC = nullptr,
50 DominatorTree *DT = nullptr);
51
52/// This pass attempts to minimize the number of assume without loosing any
53/// information.
54struct AssumeSimplifyPass : public PassInfoMixin<AssumeSimplifyPass> {
55 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
56};
57
58FunctionPass *createAssumeSimplifyPass();
59
60/// This pass will try to build an llvm.assume for every instruction in the
61/// function. Its main purpose is testing.
62struct AssumeBuilderPass : public PassInfoMixin<AssumeBuilderPass> {
63 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
64};
65
66/// canonicalize the RetainedKnowledge RK. it is assumed that RK is part of
67/// Assume. This will return an empty RetainedKnowledge if the knowledge is
68/// useless.
69RetainedKnowledge simplifyRetainedKnowledge(AssumeInst *Assume,
70 RetainedKnowledge RK,
71 AssumptionCache *AC,
72 DominatorTree *DT);
73
74} // namespace llvm
75
76#endif
77