| 1 | //===- AliasAnalysis.cpp - Alias Analysis for MLIR ------------------------===// |
|---|---|
| 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 | #include "mlir/Analysis/AliasAnalysis.h" |
| 10 | #include "mlir/Analysis/AliasAnalysis/LocalAliasAnalysis.h" |
| 11 | #include "mlir/IR/Operation.h" |
| 12 | #include "mlir/IR/Value.h" |
| 13 | #include "mlir/Support/LLVM.h" |
| 14 | #include <memory> |
| 15 | |
| 16 | using namespace mlir; |
| 17 | |
| 18 | //===----------------------------------------------------------------------===// |
| 19 | // AliasResult |
| 20 | //===----------------------------------------------------------------------===// |
| 21 | |
| 22 | /// Merge this alias result with `other` and return a new result that |
| 23 | /// represents the conservative merge of both results. |
| 24 | AliasResult AliasResult::merge(AliasResult other) const { |
| 25 | if (kind == other.kind) |
| 26 | return *this; |
| 27 | // A mix of PartialAlias and MustAlias is PartialAlias. |
| 28 | if ((isPartial() && other.isMust()) || (other.isPartial() && isMust())) |
| 29 | return PartialAlias; |
| 30 | // Otherwise, don't assume anything. |
| 31 | return MayAlias; |
| 32 | } |
| 33 | |
| 34 | void AliasResult::print(raw_ostream &os) const { |
| 35 | switch (kind) { |
| 36 | case Kind::NoAlias: |
| 37 | os << "NoAlias"; |
| 38 | break; |
| 39 | case Kind::MayAlias: |
| 40 | os << "MayAlias"; |
| 41 | break; |
| 42 | case Kind::PartialAlias: |
| 43 | os << "PartialAlias"; |
| 44 | break; |
| 45 | case Kind::MustAlias: |
| 46 | os << "MustAlias"; |
| 47 | break; |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | //===----------------------------------------------------------------------===// |
| 52 | // ModRefResult |
| 53 | //===----------------------------------------------------------------------===// |
| 54 | |
| 55 | void ModRefResult::print(raw_ostream &os) const { |
| 56 | switch (kind) { |
| 57 | case Kind::NoModRef: |
| 58 | os << "NoModRef"; |
| 59 | break; |
| 60 | case Kind::Ref: |
| 61 | os << "Ref"; |
| 62 | break; |
| 63 | case Kind::Mod: |
| 64 | os << "Mod"; |
| 65 | break; |
| 66 | case Kind::ModRef: |
| 67 | os << "ModRef"; |
| 68 | break; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | //===----------------------------------------------------------------------===// |
| 73 | // AliasAnalysis |
| 74 | //===----------------------------------------------------------------------===// |
| 75 | |
| 76 | AliasAnalysis::AliasAnalysis(Operation *op) { |
| 77 | addAnalysisImplementation(analysis: LocalAliasAnalysis()); |
| 78 | } |
| 79 | |
| 80 | AliasResult AliasAnalysis::alias(Value lhs, Value rhs) { |
| 81 | // Check each of the alias analysis implemenations for an alias result. |
| 82 | for (const std::unique_ptr<Concept> &aliasImpl : aliasImpls) { |
| 83 | AliasResult result = aliasImpl->alias(lhs, rhs); |
| 84 | if (!result.isMay()) |
| 85 | return result; |
| 86 | } |
| 87 | return AliasResult::MayAlias; |
| 88 | } |
| 89 | |
| 90 | ModRefResult AliasAnalysis::getModRef(Operation *op, Value location) { |
| 91 | // Compute the mod-ref behavior by refining a top `ModRef` result with each of |
| 92 | // the alias analysis implementations. We early exit at the point where we |
| 93 | // refine down to a `NoModRef`. |
| 94 | ModRefResult result = ModRefResult::getModAndRef(); |
| 95 | for (const std::unique_ptr<Concept> &aliasImpl : aliasImpls) { |
| 96 | result = result.intersect(other: aliasImpl->getModRef(op, location)); |
| 97 | if (result.isNoModRef()) |
| 98 | return result; |
| 99 | } |
| 100 | return result; |
| 101 | } |
| 102 |