[PM/AA] Extract a minimal interface for CFLAA to its own header file.

I've used forward declarations and reorderd the source code some to make
this reasonably clean and keep as much of the code as possible in the
source file, including all the stratified set details. Just the basic AA
interface and the create function are in the header file, and the header
file is now included into the relevant locations.

llvm-svn: 245009

3 files changed, 80 insertions, 132 deletions

diff --git a/llvm/lib/Analysis/CFLAliasAnalysis.cpp b/llvm/lib/Analysis/CFLAliasAnalysis.cpp
index e87adf14285..958ba95b3e6 100644
--- a/llvm/lib/Analysis/CFLAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/CFLAliasAnalysis.cpp
@@ -27,13 +27,13 @@
 // 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"
@@ -47,7 +47,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cassert>
-#include <forward_list>
 #include <memory>
 #include <tuple>
 
@@ -55,6 +54,63 @@ using namespace llvm;
 
 #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 *);
 
@@ -141,120 +197,6 @@ struct Edge {
       : 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;
@@ -725,16 +667,6 @@ typedef WeightedBidirectionalGraph<std::pair<EdgeType, StratifiedAttrs>> GraphT;
 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
 //===----------------------------------------------------------------------===//
@@ -784,9 +716,6 @@ static void addInstructionToGraph(CFLAliasAnalysis &, Instruction &,
 // 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();
@@ -1010,12 +939,13 @@ static bool canSkipAddingToSets(Value *Val) {
   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());
@@ -1102,11 +1032,27 @@ void CFLAliasAnalysis::scan(Function *Fn) {
   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);
diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp
index f36e5134b5a..0a705980729 100644
--- a/llvm/lib/CodeGen/Passes.cpp
+++ b/llvm/lib/CodeGen/Passes.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
+#include "llvm/Analysis/CFLAliasAnalysis.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/RegAllocRegistry.h"
diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index 9f58b49288a..0a1a56cc99c 100644
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
+#include "llvm/Analysis/CFLAliasAnalysis.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/IPO.h"