--- /dev/null
+//===- CFLAliasAnalysis.h - CFL-Based Alias Analysis Interface ---*- C++ -*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This is the interface for LLVM's primary stateless and local alias analysis.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_CFLALIASANALYSIS_H
+#define LLVM_ANALYSIS_CFLALIASANALYSIS_H
+
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/None.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include <forward_list>
+
+namespace llvm {
+
+class CFLAliasAnalysis : public ImmutablePass, public AliasAnalysis {
+ struct FunctionInfo;
+ struct FunctionHandle;
+
+ /// \brief Cached mapping of Functions to their StratifiedSets.
+ /// If a function's sets are currently being built, it is marked
+ /// in the cache as an Optional without a value. This way, if we
+ /// have any kind of recursion, it is discernable from a function
+ /// that simply has empty sets.
+ DenseMap<Function *, Optional<FunctionInfo>> Cache;
+ std::forward_list<FunctionHandle> Handles;
+
+public:
+ static char ID;
+
+ CFLAliasAnalysis();
+ ~CFLAliasAnalysis() override;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+ void *getAdjustedAnalysisPointer(const void *ID) override;
+
+ /// \brief Inserts the given Function into the cache.
+ void scan(Function *Fn);
+
+ void evict(Function *Fn);
+
+ /// \brief Ensures that the given function is available in the cache.
+ /// Returns the appropriate entry from the cache.
+ const Optional<FunctionInfo> &ensureCached(Function *Fn);
+
+ AliasResult query(const MemoryLocation &LocA, const MemoryLocation &LocB);
+
+ AliasResult alias(const MemoryLocation &LocA,
+ const MemoryLocation &LocB) override {
+ if (LocA.Ptr == LocB.Ptr) {
+ if (LocA.Size == LocB.Size) {
+ return MustAlias;
+ } else {
+ return PartialAlias;
+ }
+ }
+
+ // Comparisons between global variables and other constants should be
+ // handled by BasicAA.
+ // TODO: ConstantExpr handling -- CFLAA may report NoAlias when comparing
+ // a GlobalValue and ConstantExpr, but every query needs to have at least
+ // one Value tied to a Function, and neither GlobalValues nor ConstantExprs
+ // are.
+ if (isa<Constant>(LocA.Ptr) && isa<Constant>(LocB.Ptr)) {
+ return AliasAnalysis::alias(LocA, LocB);
+ }
+
+ AliasResult QueryResult = query(LocA, LocB);
+ if (QueryResult == MayAlias)
+ return AliasAnalysis::alias(LocA, LocB);
+
+ return QueryResult;
+ }
+
+ bool doInitialization(Module &M) override;
+
+private:
+ FunctionInfo buildSetsFrom(Function *F);
+};
+
+//===--------------------------------------------------------------------===//
+//
+// createCFLAliasAnalysisPass - This pass implements a set-based approach to
+// alias analysis.
+//
+ImmutablePass *createCFLAliasAnalysisPass();
+
+}
+
+#endif
// time.
//===----------------------------------------------------------------------===//
+#include "llvm/Analysis/CFLAliasAnalysis.h"
#include "StratifiedSets.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/Passes.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstVisitor.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
-#include <forward_list>
#include <memory>
#include <tuple>
#define DEBUG_TYPE "cfl-aa"
+// -- Setting up/registering CFLAA pass -- //
+char CFLAliasAnalysis::ID = 0;
+
+INITIALIZE_AG_PASS(CFLAliasAnalysis, AliasAnalysis, "cfl-aa",
+ "CFL-Based AA implementation", false, true, false)
+
+ImmutablePass *llvm::createCFLAliasAnalysisPass() {
+ return new CFLAliasAnalysis();
+}
+
+// \brief Information we have about a function and would like to keep around
+struct CFLAliasAnalysis::FunctionInfo {
+ StratifiedSets<Value *> Sets;
+ // Lots of functions have < 4 returns. Adjust as necessary.
+ SmallVector<Value *, 4> ReturnedValues;
+
+ FunctionInfo(StratifiedSets<Value *> &&S, SmallVector<Value *, 4> &&RV)
+ : Sets(std::move(S)), ReturnedValues(std::move(RV)) {}
+};
+
+struct CFLAliasAnalysis::FunctionHandle final : public CallbackVH {
+ FunctionHandle(Function *Fn, CFLAliasAnalysis *CFLAA)
+ : CallbackVH(Fn), CFLAA(CFLAA) {
+ assert(Fn != nullptr);
+ assert(CFLAA != nullptr);
+ }
+
+ void deleted() override { removeSelfFromCache(); }
+ void allUsesReplacedWith(Value *) override { removeSelfFromCache(); }
+
+private:
+ CFLAliasAnalysis *CFLAA;
+
+ void removeSelfFromCache() {
+ assert(CFLAA != nullptr);
+ auto *Val = getValPtr();
+ CFLAA->evict(cast<Function>(Val));
+ setValPtr(nullptr);
+ }
+};
+
+CFLAliasAnalysis::CFLAliasAnalysis() : ImmutablePass(ID) {
+ initializeCFLAliasAnalysisPass(*PassRegistry::getPassRegistry());
+}
+
+CFLAliasAnalysis::~CFLAliasAnalysis() {}
+
+void CFLAliasAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+ AliasAnalysis::getAnalysisUsage(AU);
+}
+
+void *CFLAliasAnalysis::getAdjustedAnalysisPointer(const void *ID) {
+ if (ID == &AliasAnalysis::ID)
+ return (AliasAnalysis *)this;
+ return this;
+}
+
// Try to go from a Value* to a Function*. Never returns nullptr.
static Optional<Function *> parentFunctionOfValue(Value *);
: From(From), To(To), Weight(W), AdditionalAttrs(A) {}
};
-// \brief Information we have about a function and would like to keep around
-struct FunctionInfo {
- StratifiedSets<Value *> Sets;
- // Lots of functions have < 4 returns. Adjust as necessary.
- SmallVector<Value *, 4> ReturnedValues;
-
- FunctionInfo(StratifiedSets<Value *> &&S, SmallVector<Value *, 4> &&RV)
- : Sets(std::move(S)), ReturnedValues(std::move(RV)) {}
-};
-
-struct CFLAliasAnalysis;
-
-struct FunctionHandle final : public CallbackVH {
- FunctionHandle(Function *Fn, CFLAliasAnalysis *CFLAA)
- : CallbackVH(Fn), CFLAA(CFLAA) {
- assert(Fn != nullptr);
- assert(CFLAA != nullptr);
- }
-
- void deleted() override { removeSelfFromCache(); }
- void allUsesReplacedWith(Value *) override { removeSelfFromCache(); }
-
-private:
- CFLAliasAnalysis *CFLAA;
-
- void removeSelfFromCache();
-};
-
-struct CFLAliasAnalysis : public ImmutablePass, public AliasAnalysis {
-private:
- /// \brief Cached mapping of Functions to their StratifiedSets.
- /// If a function's sets are currently being built, it is marked
- /// in the cache as an Optional without a value. This way, if we
- /// have any kind of recursion, it is discernable from a function
- /// that simply has empty sets.
- DenseMap<Function *, Optional<FunctionInfo>> Cache;
- std::forward_list<FunctionHandle> Handles;
-
-public:
- static char ID;
-
- CFLAliasAnalysis() : ImmutablePass(ID) {
- initializeCFLAliasAnalysisPass(*PassRegistry::getPassRegistry());
- }
-
- ~CFLAliasAnalysis() override {}
-
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AliasAnalysis::getAnalysisUsage(AU);
- }
-
- void *getAdjustedAnalysisPointer(const void *ID) override {
- if (ID == &AliasAnalysis::ID)
- return (AliasAnalysis *)this;
- return this;
- }
-
- /// \brief Inserts the given Function into the cache.
- void scan(Function *Fn);
-
- void evict(Function *Fn) { Cache.erase(Fn); }
-
- /// \brief Ensures that the given function is available in the cache.
- /// Returns the appropriate entry from the cache.
- const Optional<FunctionInfo> &ensureCached(Function *Fn) {
- auto Iter = Cache.find(Fn);
- if (Iter == Cache.end()) {
- scan(Fn);
- Iter = Cache.find(Fn);
- assert(Iter != Cache.end());
- assert(Iter->second.hasValue());
- }
- return Iter->second;
- }
-
- AliasResult query(const MemoryLocation &LocA, const MemoryLocation &LocB);
-
- AliasResult alias(const MemoryLocation &LocA,
- const MemoryLocation &LocB) override {
- if (LocA.Ptr == LocB.Ptr) {
- if (LocA.Size == LocB.Size) {
- return MustAlias;
- } else {
- return PartialAlias;
- }
- }
-
- // Comparisons between global variables and other constants should be
- // handled by BasicAA.
- // TODO: ConstantExpr handling -- CFLAA may report NoAlias when comparing
- // a GlobalValue and ConstantExpr, but every query needs to have at least
- // one Value tied to a Function, and neither GlobalValues nor ConstantExprs
- // are.
- if (isa<Constant>(LocA.Ptr) && isa<Constant>(LocB.Ptr)) {
- return AliasAnalysis::alias(LocA, LocB);
- }
-
- AliasResult QueryResult = query(LocA, LocB);
- if (QueryResult == MayAlias)
- return AliasAnalysis::alias(LocA, LocB);
-
- return QueryResult;
- }
-
- bool doInitialization(Module &M) override;
-};
-
-void FunctionHandle::removeSelfFromCache() {
- assert(CFLAA != nullptr);
- auto *Val = getValPtr();
- CFLAA->evict(cast<Function>(Val));
- setValPtr(nullptr);
-}
-
// \brief Gets the edges our graph should have, based on an Instruction*
class GetEdgesVisitor : public InstVisitor<GetEdgesVisitor, void> {
CFLAliasAnalysis &AA;
typedef DenseMap<Value *, GraphT::Node> NodeMapT;
}
-// -- Setting up/registering CFLAA pass -- //
-char CFLAliasAnalysis::ID = 0;
-
-INITIALIZE_AG_PASS(CFLAliasAnalysis, AliasAnalysis, "cfl-aa",
- "CFL-Based AA implementation", false, true, false)
-
-ImmutablePass *llvm::createCFLAliasAnalysisPass() {
- return new CFLAliasAnalysis();
-}
-
//===----------------------------------------------------------------------===//
// Function declarations that require types defined in the namespace above
//===----------------------------------------------------------------------===//
// Notes whether it would be pointless to add the given Value to our sets.
static bool canSkipAddingToSets(Value *Val);
-// Builds the graph + StratifiedSets for a function.
-static FunctionInfo buildSetsFrom(CFLAliasAnalysis &, Function *);
-
static Optional<Function *> parentFunctionOfValue(Value *Val) {
if (auto *Inst = dyn_cast<Instruction>(Val)) {
auto *Bb = Inst->getParent();
return false;
}
-static FunctionInfo buildSetsFrom(CFLAliasAnalysis &Analysis, Function *Fn) {
+// Builds the graph + StratifiedSets for a function.
+CFLAliasAnalysis::FunctionInfo CFLAliasAnalysis::buildSetsFrom(Function *Fn) {
NodeMapT Map;
GraphT Graph;
SmallVector<Value *, 4> ReturnedValues;
- buildGraphFrom(Analysis, Fn, ReturnedValues, Map, Graph);
+ buildGraphFrom(*this, Fn, ReturnedValues, Map, Graph);
DenseMap<GraphT::Node, Value *> NodeValueMap;
NodeValueMap.resize(Map.size());
assert(InsertPair.second &&
"Trying to scan a function that has already been cached");
- FunctionInfo Info(buildSetsFrom(*this, Fn));
+ FunctionInfo Info(buildSetsFrom(Fn));
Cache[Fn] = std::move(Info);
Handles.push_front(FunctionHandle(Fn, this));
}
+void CFLAliasAnalysis::evict(Function *Fn) { Cache.erase(Fn); }
+
+/// \brief Ensures that the given function is available in the cache.
+/// Returns the appropriate entry from the cache.
+const Optional<CFLAliasAnalysis::FunctionInfo> &
+CFLAliasAnalysis::ensureCached(Function *Fn) {
+ auto Iter = Cache.find(Fn);
+ if (Iter == Cache.end()) {
+ scan(Fn);
+ Iter = Cache.find(Fn);
+ assert(Iter != Cache.end());
+ assert(Iter->second.hasValue());
+ }
+ return Iter->second;
+}
+
AliasResult CFLAliasAnalysis::query(const MemoryLocation &LocA,
const MemoryLocation &LocB) {
auto *ValA = const_cast<Value *>(LocA.Ptr);