6024e5c395
clang 20.0.0 (based on r547379) from build 12806354. Bug: http://b/379133546 Test: N/A Change-Id: I2eb8938af55d809de674be63cb30cf27e801862b Upstream-Commit: ad834e67b1105d15ef907f6255d4c96e8e733f57
281 lines
9.6 KiB
C++
281 lines
9.6 KiB
C++
//===- llvm/Analysis/AliasSetTracker.h - Build Alias Sets -------*- C++ -*-===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines two classes: AliasSetTracker and AliasSet. These interfaces
|
|
// are used to classify a collection of memory locations into a maximal number
|
|
// of disjoint sets. Each AliasSet object constructed by the AliasSetTracker
|
|
// object refers to memory disjoint from the other sets.
|
|
//
|
|
// An AliasSetTracker can only be used on immutable IR.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_ANALYSIS_ALIASSETTRACKER_H
|
|
#define LLVM_ANALYSIS_ALIASSETTRACKER_H
|
|
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/ADT/ilist.h"
|
|
#include "llvm/ADT/ilist_node.h"
|
|
#include "llvm/Analysis/MemoryLocation.h"
|
|
#include "llvm/IR/PassManager.h"
|
|
#include "llvm/IR/ValueHandle.h"
|
|
#include <cassert>
|
|
#include <vector>
|
|
|
|
namespace llvm {
|
|
|
|
class AliasResult;
|
|
class AliasSetTracker;
|
|
class AnyMemSetInst;
|
|
class AnyMemTransferInst;
|
|
class BasicBlock;
|
|
class BatchAAResults;
|
|
class Function;
|
|
class Instruction;
|
|
class StoreInst;
|
|
class LoadInst;
|
|
enum class ModRefInfo : uint8_t;
|
|
class raw_ostream;
|
|
class VAArgInst;
|
|
class Value;
|
|
|
|
class AliasSet : public ilist_node<AliasSet> {
|
|
friend class AliasSetTracker;
|
|
|
|
// Forwarding pointer.
|
|
AliasSet *Forward = nullptr;
|
|
|
|
/// Memory locations in this alias set.
|
|
SmallVector<MemoryLocation, 0> MemoryLocs;
|
|
|
|
/// All instructions without a specific address in this alias set.
|
|
std::vector<AssertingVH<Instruction>> UnknownInsts;
|
|
|
|
/// Number of nodes pointing to this AliasSet plus the number of AliasSets
|
|
/// forwarding to it.
|
|
unsigned RefCount : 27;
|
|
|
|
// Signifies that this set should be considered to alias any pointer.
|
|
// Use when the tracker holding this set is saturated.
|
|
unsigned AliasAny : 1;
|
|
|
|
/// The kinds of access this alias set models.
|
|
///
|
|
/// We keep track of whether this alias set merely refers to the locations of
|
|
/// memory (and not any particular access), whether it modifies or references
|
|
/// the memory, or whether it does both. The lattice goes from "NoAccess" to
|
|
/// either RefAccess or ModAccess, then to ModRefAccess as necessary.
|
|
enum AccessLattice {
|
|
NoAccess = 0,
|
|
RefAccess = 1,
|
|
ModAccess = 2,
|
|
ModRefAccess = RefAccess | ModAccess
|
|
};
|
|
unsigned Access : 2;
|
|
|
|
/// The kind of alias relationship between pointers of the set.
|
|
///
|
|
/// These represent conservatively correct alias results between any members
|
|
/// of the set. We represent these independently of the values of alias
|
|
/// results in order to pack it into a single bit. Lattice goes from
|
|
/// MustAlias to MayAlias.
|
|
enum AliasLattice {
|
|
SetMustAlias = 0, SetMayAlias = 1
|
|
};
|
|
unsigned Alias : 1;
|
|
|
|
void addRef() { ++RefCount; }
|
|
|
|
void dropRef(AliasSetTracker &AST) {
|
|
assert(RefCount >= 1 && "Invalid reference count detected!");
|
|
if (--RefCount == 0)
|
|
removeFromTracker(AST);
|
|
}
|
|
|
|
public:
|
|
AliasSet(const AliasSet &) = delete;
|
|
AliasSet &operator=(const AliasSet &) = delete;
|
|
|
|
/// Accessors...
|
|
bool isRef() const { return Access & RefAccess; }
|
|
bool isMod() const { return Access & ModAccess; }
|
|
bool isMustAlias() const { return Alias == SetMustAlias; }
|
|
bool isMayAlias() const { return Alias == SetMayAlias; }
|
|
|
|
/// Return true if this alias set should be ignored as part of the
|
|
/// AliasSetTracker object.
|
|
bool isForwardingAliasSet() const { return Forward; }
|
|
|
|
/// Merge the specified alias set into this alias set.
|
|
void mergeSetIn(AliasSet &AS, AliasSetTracker &AST, BatchAAResults &BatchAA);
|
|
|
|
// Alias Set iteration - Allow access to all of the memory locations which are
|
|
// part of this alias set.
|
|
using iterator = SmallVectorImpl<MemoryLocation>::const_iterator;
|
|
iterator begin() const { return MemoryLocs.begin(); }
|
|
iterator end() const { return MemoryLocs.end(); }
|
|
|
|
unsigned size() const { return MemoryLocs.size(); }
|
|
|
|
/// Retrieve the pointer values for the memory locations in this alias set.
|
|
/// The order matches that of the memory locations, but duplicate pointer
|
|
/// values are omitted.
|
|
using PointerVector = SmallVector<const Value *, 8>;
|
|
PointerVector getPointers() const;
|
|
|
|
void print(raw_ostream &OS) const;
|
|
void dump() const;
|
|
|
|
private:
|
|
// Can only be created by AliasSetTracker.
|
|
AliasSet()
|
|
: RefCount(0), AliasAny(false), Access(NoAccess), Alias(SetMustAlias) {}
|
|
|
|
void removeFromTracker(AliasSetTracker &AST);
|
|
|
|
void addMemoryLocation(AliasSetTracker &AST, const MemoryLocation &MemLoc,
|
|
bool KnownMustAlias = false);
|
|
void addUnknownInst(Instruction *I, BatchAAResults &AA);
|
|
|
|
public:
|
|
/// If the specified memory location "may" (or must) alias one of the members
|
|
/// in the set return the appropriate AliasResult. Otherwise return NoAlias.
|
|
AliasResult aliasesMemoryLocation(const MemoryLocation &MemLoc,
|
|
BatchAAResults &AA) const;
|
|
|
|
ModRefInfo aliasesUnknownInst(const Instruction *Inst,
|
|
BatchAAResults &AA) const;
|
|
};
|
|
|
|
inline raw_ostream& operator<<(raw_ostream &OS, const AliasSet &AS) {
|
|
AS.print(OS);
|
|
return OS;
|
|
}
|
|
|
|
class AliasSetTracker {
|
|
BatchAAResults &AA;
|
|
ilist<AliasSet> AliasSets;
|
|
|
|
using PointerMapType = DenseMap<AssertingVH<const Value>, AliasSet *>;
|
|
|
|
// Map from pointer values to the alias set holding one or more memory
|
|
// locations with that pointer value.
|
|
PointerMapType PointerMap;
|
|
|
|
public:
|
|
/// Create an empty collection of AliasSets, and use the specified alias
|
|
/// analysis object to disambiguate load and store addresses.
|
|
explicit AliasSetTracker(BatchAAResults &AA) : AA(AA) {}
|
|
~AliasSetTracker() { clear(); }
|
|
|
|
/// These methods are used to add different types of instructions to the alias
|
|
/// sets. Adding a new instruction can result in one of three actions
|
|
/// happening:
|
|
///
|
|
/// 1. If the instruction doesn't alias any other sets, create a new set.
|
|
/// 2. If the instruction aliases exactly one set, add it to the set
|
|
/// 3. If the instruction aliases multiple sets, merge the sets, and add
|
|
/// the instruction to the result.
|
|
///
|
|
void add(const MemoryLocation &Loc);
|
|
void add(LoadInst *LI);
|
|
void add(StoreInst *SI);
|
|
void add(VAArgInst *VAAI);
|
|
void add(AnyMemSetInst *MSI);
|
|
void add(AnyMemTransferInst *MTI);
|
|
void add(Instruction *I); // Dispatch to one of the other add methods...
|
|
void add(BasicBlock &BB); // Add all instructions in basic block
|
|
void add(const AliasSetTracker &AST); // Add alias relations from another AST
|
|
void addUnknown(Instruction *I);
|
|
|
|
void clear();
|
|
|
|
/// Return the alias sets that are active.
|
|
const ilist<AliasSet> &getAliasSets() const { return AliasSets; }
|
|
|
|
/// Return the alias set which contains the specified memory location. If
|
|
/// the memory location aliases two or more existing alias sets, will have
|
|
/// the effect of merging those alias sets before the single resulting alias
|
|
/// set is returned.
|
|
AliasSet &getAliasSetFor(const MemoryLocation &MemLoc);
|
|
|
|
/// Return the underlying alias analysis object used by this tracker.
|
|
BatchAAResults &getAliasAnalysis() const { return AA; }
|
|
|
|
using iterator = ilist<AliasSet>::iterator;
|
|
using const_iterator = ilist<AliasSet>::const_iterator;
|
|
|
|
const_iterator begin() const { return AliasSets.begin(); }
|
|
const_iterator end() const { return AliasSets.end(); }
|
|
|
|
iterator begin() { return AliasSets.begin(); }
|
|
iterator end() { return AliasSets.end(); }
|
|
|
|
void print(raw_ostream &OS) const;
|
|
void dump() const;
|
|
|
|
private:
|
|
friend class AliasSet;
|
|
|
|
// The total number of memory locations contained in all alias sets.
|
|
unsigned TotalAliasSetSize = 0;
|
|
|
|
// A non-null value signifies this AST is saturated. A saturated AST lumps
|
|
// all elements into a single "May" set.
|
|
AliasSet *AliasAnyAS = nullptr;
|
|
|
|
void removeAliasSet(AliasSet *AS);
|
|
|
|
// Update an alias set field to point to its real destination. If the field is
|
|
// pointing to a set that has been merged with another set and is forwarding,
|
|
// the field is updated to point to the set obtained by following the
|
|
// forwarding links. The Forward fields of intermediate alias sets are
|
|
// collapsed as well, and alias set reference counts are updated to reflect
|
|
// the new situation.
|
|
void collapseForwardingIn(AliasSet *&AS) {
|
|
if (AS->Forward) {
|
|
collapseForwardingIn(AS->Forward);
|
|
// Swap out AS for AS->Forward, while updating reference counts.
|
|
AliasSet *NewAS = AS->Forward;
|
|
NewAS->addRef();
|
|
AS->dropRef(*this);
|
|
AS = NewAS;
|
|
}
|
|
}
|
|
|
|
AliasSet &addMemoryLocation(MemoryLocation Loc, AliasSet::AccessLattice E);
|
|
AliasSet *mergeAliasSetsForMemoryLocation(const MemoryLocation &MemLoc,
|
|
AliasSet *PtrAS,
|
|
bool &MustAliasAll);
|
|
|
|
/// Merge all alias sets into a single set that is considered to alias
|
|
/// any memory location or instruction.
|
|
AliasSet &mergeAllAliasSets();
|
|
|
|
AliasSet *findAliasSetForUnknownInst(Instruction *Inst);
|
|
};
|
|
|
|
inline raw_ostream& operator<<(raw_ostream &OS, const AliasSetTracker &AST) {
|
|
AST.print(OS);
|
|
return OS;
|
|
}
|
|
|
|
class AliasSetsPrinterPass : public PassInfoMixin<AliasSetsPrinterPass> {
|
|
raw_ostream &OS;
|
|
|
|
public:
|
|
explicit AliasSetsPrinterPass(raw_ostream &OS);
|
|
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
|
|
static bool isRequired() { return true; }
|
|
};
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_ANALYSIS_ALIASSETTRACKER_H
|