1 files changed, 74 insertions, 188 deletions

diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index 5cc840a64a627..d6308b7073a09 100644
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -38,11 +38,11 @@
 #ifndef LLVM_ANALYSIS_ALIASANALYSIS_H
 #define LLVM_ANALYSIS_ALIASANALYSIS_H
 
-#include "llvm/ADT/DenseMap.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Analysis/MemoryLocation.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
 
 namespace llvm {
 class BasicAAResult;
@@ -50,7 +50,6 @@ class LoadInst;
 class StoreInst;
 class VAArgInst;
 class DataLayout;
-class TargetLibraryInfo;
 class Pass;
 class AnalysisUsage;
 class MemTransferInst;
@@ -141,7 +140,7 @@ enum FunctionModRefBehavior {
   /// non-volatile loads and stores from objects pointed to by its
   /// pointer-typed arguments, with arbitrary offsets.
   ///
-  /// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
+  /// This property corresponds to the IntrArgMemOnly LLVM intrinsic flag.
   FMRB_OnlyAccessesArgumentPointees = FMRL_ArgumentPointees | MRI_ModRef,
 
   /// This function does not perform any non-local stores or volatile loads,
@@ -152,6 +151,13 @@ enum FunctionModRefBehavior {
   /// This property corresponds to the IntrReadMem LLVM intrinsic flag.
   FMRB_OnlyReadsMemory = FMRL_Anywhere | MRI_Ref,
 
+  // This function does not read from memory anywhere, but may write to any
+  // memory location.
+  //
+  // This property corresponds to the LLVM IR 'writeonly' attribute.
+  // This property corresponds to the IntrWriteMem LLVM intrinsic flag.
+  FMRB_DoesNotReadMemory = FMRL_Anywhere | MRI_Mod,
+
   /// This indicates that the function could not be classified into one of the
   /// behaviors above.
   FMRB_UnknownModRefBehavior = FMRL_Anywhere | MRI_ModRef
@@ -161,9 +167,8 @@ class AAResults {
 public:
   // Make these results default constructable and movable. We have to spell
   // these out because MSVC won't synthesize them.
-  AAResults() {}
+  AAResults(const TargetLibraryInfo &TLI) : TLI(TLI) {}
   AAResults(AAResults &&Arg);
-  AAResults &operator=(AAResults &&Arg);
   ~AAResults();
 
   /// Register a specific AA result.
@@ -314,6 +319,12 @@ public:
     return !(MRB & MRI_Mod);
   }
 
+  /// Checks if functions with the specified behavior are known to only write
+  /// memory (or not access memory at all).
+  static bool doesNotReadMemory(FunctionModRefBehavior MRB) {
+    return !(MRB & MRI_Ref);
+  }
+
   /// Checks if functions with the specified behavior are known to read and
   /// write at most from objects pointed to by their pointer-typed arguments
   /// (with arbitrary offsets).
@@ -450,11 +461,11 @@ public:
   ModRefInfo getModRefInfo(const Instruction *I) {
     if (auto CS = ImmutableCallSite(I)) {
       auto MRB = getModRefBehavior(CS);
-      if (MRB & MRI_ModRef)
+      if ((MRB & MRI_ModRef) == MRI_ModRef)
         return MRI_ModRef;
-      else if (MRB & MRI_Ref)
+      if (MRB & MRI_Ref)
         return MRI_Ref;
-      else if (MRB & MRI_Mod)
+      if (MRB & MRI_Mod)
         return MRI_Mod;
       return MRI_NoModRef;
     }
@@ -557,6 +568,8 @@ private:
 
   template <typename T> friend class AAResultBase;
 
+  const TargetLibraryInfo &TLI;
+
   std::vector<std::unique_ptr<Concept>> AAs;
 };
 
@@ -753,20 +766,23 @@ protected:
     }
   };
 
-  const TargetLibraryInfo &TLI;
-
-  explicit AAResultBase(const TargetLibraryInfo &TLI) : TLI(TLI) {}
+  explicit AAResultBase() {}
 
   // Provide all the copy and move constructors so that derived types aren't
   // constrained.
-  AAResultBase(const AAResultBase &Arg) : TLI(Arg.TLI) {}
-  AAResultBase(AAResultBase &&Arg) : TLI(Arg.TLI) {}
+  AAResultBase(const AAResultBase &Arg) {}
+  AAResultBase(AAResultBase &&Arg) {}
 
   /// Get a proxy for the best AA result set to query at this time.
   ///
   /// When this result is part of a larger aggregation, this will proxy to that
   /// aggregation. When this result is used in isolation, it will just delegate
   /// back to the derived class's implementation.
+  ///
+  /// Note that callers of this need to take considerable care to not cause
+  /// performance problems when they use this routine, in the case of a large
+  /// number of alias analyses being aggregated, it can be expensive to walk
+  /// back across the chain.
   AAResultsProxy getBestAAResults() { return AAResultsProxy(AAR, derived()); }
 
 public:
@@ -783,13 +799,6 @@ public:
   }
 
   FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS) {
-    if (!CS.hasOperandBundles())
-      // If CS has operand bundles then aliasing attributes from the function it
-      // calls do not directly apply to the CallSite.  This can be made more
-      // precise in the future.
-      if (const Function *F = CS.getCalledFunction())
-        return getBestAAResults().getModRefBehavior(F);
-
     return FMRB_UnknownModRefBehavior;
   }
 
@@ -797,170 +806,24 @@ public:
     return FMRB_UnknownModRefBehavior;
   }
 
-  ModRefInfo getModRefInfo(ImmutableCallSite CS, const MemoryLocation &Loc);
-
-  ModRefInfo getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2);
-};
-
-/// Synthesize \c ModRefInfo for a call site and memory location by examining
-/// the general behavior of the call site and any specific information for its
-/// arguments.
-///
-/// This essentially, delegates across the alias analysis interface to collect
-/// information which may be enough to (conservatively) fulfill the query.
-template <typename DerivedT>
-ModRefInfo AAResultBase<DerivedT>::getModRefInfo(ImmutableCallSite CS,
-                                                 const MemoryLocation &Loc) {
-  auto MRB = getBestAAResults().getModRefBehavior(CS);
-  if (MRB == FMRB_DoesNotAccessMemory)
-    return MRI_NoModRef;
-
-  ModRefInfo Mask = MRI_ModRef;
-  if (AAResults::onlyReadsMemory(MRB))
-    Mask = MRI_Ref;
-
-  if (AAResults::onlyAccessesArgPointees(MRB)) {
-    bool DoesAlias = false;
-    ModRefInfo AllArgsMask = MRI_NoModRef;
-    if (AAResults::doesAccessArgPointees(MRB)) {
-      for (ImmutableCallSite::arg_iterator AI = CS.arg_begin(),
-                                           AE = CS.arg_end();
-           AI != AE; ++AI) {
-        const Value *Arg = *AI;
-        if (!Arg->getType()->isPointerTy())
-          continue;
-        unsigned ArgIdx = std::distance(CS.arg_begin(), AI);
-        MemoryLocation ArgLoc = MemoryLocation::getForArgument(CS, ArgIdx, TLI);
-        AliasResult ArgAlias = getBestAAResults().alias(ArgLoc, Loc);
-        if (ArgAlias != NoAlias) {
-          ModRefInfo ArgMask = getBestAAResults().getArgModRefInfo(CS, ArgIdx);
-          DoesAlias = true;
-          AllArgsMask = ModRefInfo(AllArgsMask | ArgMask);
-        }
-      }
-    }
-    if (!DoesAlias)
-      return MRI_NoModRef;
-    Mask = ModRefInfo(Mask & AllArgsMask);
-  }
-
-  // If Loc is a constant memory location, the call definitely could not
-  // modify the memory location.
-  if ((Mask & MRI_Mod) &&
-      getBestAAResults().pointsToConstantMemory(Loc, /*OrLocal*/ false))
-    Mask = ModRefInfo(Mask & ~MRI_Mod);
-
-  return Mask;
-}
-
-/// Synthesize \c ModRefInfo for two call sites by examining the general
-/// behavior of the call site and any specific information for its arguments.
-///
-/// This essentially, delegates across the alias analysis interface to collect
-/// information which may be enough to (conservatively) fulfill the query.
-template <typename DerivedT>
-ModRefInfo AAResultBase<DerivedT>::getModRefInfo(ImmutableCallSite CS1,
-                                                 ImmutableCallSite CS2) {
-  // If CS1 or CS2 are readnone, they don't interact.
-  auto CS1B = getBestAAResults().getModRefBehavior(CS1);
-  if (CS1B == FMRB_DoesNotAccessMemory)
-    return MRI_NoModRef;
-
-  auto CS2B = getBestAAResults().getModRefBehavior(CS2);
-  if (CS2B == FMRB_DoesNotAccessMemory)
-    return MRI_NoModRef;
-
-  // If they both only read from memory, there is no dependence.
-  if (AAResults::onlyReadsMemory(CS1B) && AAResults::onlyReadsMemory(CS2B))
-    return MRI_NoModRef;
-
-  ModRefInfo Mask = MRI_ModRef;
-
-  // If CS1 only reads memory, the only dependence on CS2 can be
-  // from CS1 reading memory written by CS2.
-  if (AAResults::onlyReadsMemory(CS1B))
-    Mask = ModRefInfo(Mask & MRI_Ref);
-
-  // If CS2 only access memory through arguments, accumulate the mod/ref
-  // information from CS1's references to the memory referenced by
-  // CS2's arguments.
-  if (AAResults::onlyAccessesArgPointees(CS2B)) {
-    ModRefInfo R = MRI_NoModRef;
-    if (AAResults::doesAccessArgPointees(CS2B)) {
-      for (ImmutableCallSite::arg_iterator I = CS2.arg_begin(),
-                                           E = CS2.arg_end();
-           I != E; ++I) {
-        const Value *Arg = *I;
-        if (!Arg->getType()->isPointerTy())
-          continue;
-        unsigned CS2ArgIdx = std::distance(CS2.arg_begin(), I);
-        auto CS2ArgLoc = MemoryLocation::getForArgument(CS2, CS2ArgIdx, TLI);
-
-        // ArgMask indicates what CS2 might do to CS2ArgLoc, and the dependence
-        // of CS1 on that location is the inverse.
-        ModRefInfo ArgMask =
-            getBestAAResults().getArgModRefInfo(CS2, CS2ArgIdx);
-        if (ArgMask == MRI_Mod)
-          ArgMask = MRI_ModRef;
-        else if (ArgMask == MRI_Ref)
-          ArgMask = MRI_Mod;
-
-        ArgMask = ModRefInfo(ArgMask &
-                             getBestAAResults().getModRefInfo(CS1, CS2ArgLoc));
-
-        R = ModRefInfo((R | ArgMask) & Mask);
-        if (R == Mask)
-          break;
-      }
-    }
-    return R;
+  ModRefInfo getModRefInfo(ImmutableCallSite CS, const MemoryLocation &Loc) {
+    return MRI_ModRef;
   }
 
-  // If CS1 only accesses memory through arguments, check if CS2 references
-  // any of the memory referenced by CS1's arguments. If not, return NoModRef.
-  if (AAResults::onlyAccessesArgPointees(CS1B)) {
-    ModRefInfo R = MRI_NoModRef;
-    if (AAResults::doesAccessArgPointees(CS1B)) {
-      for (ImmutableCallSite::arg_iterator I = CS1.arg_begin(),
-                                           E = CS1.arg_end();
-           I != E; ++I) {
-        const Value *Arg = *I;
-        if (!Arg->getType()->isPointerTy())
-          continue;
-        unsigned CS1ArgIdx = std::distance(CS1.arg_begin(), I);
-        auto CS1ArgLoc = MemoryLocation::getForArgument(CS1, CS1ArgIdx, TLI);
-
-        // ArgMask indicates what CS1 might do to CS1ArgLoc; if CS1 might Mod
-        // CS1ArgLoc, then we care about either a Mod or a Ref by CS2. If CS1
-        // might Ref, then we care only about a Mod by CS2.
-        ModRefInfo ArgMask = getBestAAResults().getArgModRefInfo(CS1, CS1ArgIdx);
-        ModRefInfo ArgR = getBestAAResults().getModRefInfo(CS2, CS1ArgLoc);
-        if (((ArgMask & MRI_Mod) != MRI_NoModRef &&
-             (ArgR & MRI_ModRef) != MRI_NoModRef) ||
-            ((ArgMask & MRI_Ref) != MRI_NoModRef &&
-             (ArgR & MRI_Mod) != MRI_NoModRef))
-          R = ModRefInfo((R | ArgMask) & Mask);
-
-        if (R == Mask)
-          break;
-      }
-    }
-    return R;
+  ModRefInfo getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) {
+    return MRI_ModRef;
   }
+};
 
-  return Mask;
-}
 
-/// isNoAliasCall - Return true if this pointer is returned by a noalias
-/// function.
+/// Return true if this pointer is returned by a noalias function.
 bool isNoAliasCall(const Value *V);
 
-/// isNoAliasArgument - Return true if this is an argument with the noalias
-/// attribute.
+/// Return true if this is an argument with the noalias attribute.
 bool isNoAliasArgument(const Value *V);
 
-/// isIdentifiedObject - Return true if this pointer refers to a distinct and
-/// identifiable object.  This returns true for:
+/// Return true if this pointer refers to a distinct and identifiable object.
+/// This returns true for:
 ///    Global Variables and Functions (but not Global Aliases)
 ///    Allocas
 ///    ByVal and NoAlias Arguments
@@ -968,8 +831,8 @@ bool isNoAliasArgument(const Value *V);
 ///
 bool isIdentifiedObject(const Value *V);
 
-/// isIdentifiedFunctionLocal - Return true if V is umabigously identified
-/// at the function-level. Different IdentifiedFunctionLocals can't alias.
+/// Return true if V is umabigously identified at the function-level.
+/// Different IdentifiedFunctionLocals can't alias.
 /// Further, an IdentifiedFunctionLocal can not alias with any function
 /// arguments other than itself, which is not necessarily true for
 /// IdentifiedObjects.
@@ -987,42 +850,48 @@ bool isIdentifiedFunctionLocal(const Value *V);
 /// This manager effectively wraps the AnalysisManager for registering alias
 /// analyses. When you register your alias analysis with this manager, it will
 /// ensure the analysis itself is registered with its AnalysisManager.
-class AAManager {
+class AAManager : public AnalysisInfoMixin<AAManager> {
 public:
   typedef AAResults Result;
 
   // This type hase value semantics. We have to spell these out because MSVC
   // won't synthesize them.
   AAManager() {}
-  AAManager(AAManager &&Arg)
-      : FunctionResultGetters(std::move(Arg.FunctionResultGetters)) {}
-  AAManager(const AAManager &Arg)
-      : FunctionResultGetters(Arg.FunctionResultGetters) {}
+  AAManager(AAManager &&Arg) : ResultGetters(std::move(Arg.ResultGetters)) {}
+  AAManager(const AAManager &Arg) : ResultGetters(Arg.ResultGetters) {}
   AAManager &operator=(AAManager &&RHS) {
-    FunctionResultGetters = std::move(RHS.FunctionResultGetters);
+    ResultGetters = std::move(RHS.ResultGetters);
     return *this;
   }
   AAManager &operator=(const AAManager &RHS) {
-    FunctionResultGetters = RHS.FunctionResultGetters;
+    ResultGetters = RHS.ResultGetters;
     return *this;
   }
 
   /// Register a specific AA result.
   template <typename AnalysisT> void registerFunctionAnalysis() {
-    FunctionResultGetters.push_back(&getFunctionAAResultImpl<AnalysisT>);
+    ResultGetters.push_back(&getFunctionAAResultImpl<AnalysisT>);
+  }
+
+  /// Register a specific AA result.
+  template <typename AnalysisT> void registerModuleAnalysis() {
+    ResultGetters.push_back(&getModuleAAResultImpl<AnalysisT>);
   }
 
   Result run(Function &F, AnalysisManager<Function> &AM) {
-    Result R;
-    for (auto &Getter : FunctionResultGetters)
+    Result R(AM.getResult<TargetLibraryAnalysis>(F));
+    for (auto &Getter : ResultGetters)
       (*Getter)(F, AM, R);
     return R;
   }
 
 private:
+  friend AnalysisInfoMixin<AAManager>;
+  static char PassID;
+
   SmallVector<void (*)(Function &F, AnalysisManager<Function> &AM,
                        AAResults &AAResults),
-              4> FunctionResultGetters;
+              4> ResultGetters;
 
   template <typename AnalysisT>
   static void getFunctionAAResultImpl(Function &F,
@@ -1030,6 +899,15 @@ private:
                                       AAResults &AAResults) {
     AAResults.addAAResult(AM.template getResult<AnalysisT>(F));
   }
+
+  template <typename AnalysisT>
+  static void getModuleAAResultImpl(Function &F, AnalysisManager<Function> &AM,
+                                    AAResults &AAResults) {
+    auto &MAM =
+        AM.getResult<ModuleAnalysisManagerFunctionProxy>(F).getManager();
+    if (auto *R = MAM.template getCachedResult<AnalysisT>(*F.getParent()))
+      AAResults.addAAResult(*R);
+  }
 };
 
 /// A wrapper pass to provide the legacy pass manager access to a suitably
@@ -1065,8 +943,16 @@ ImmutablePass *createExternalAAWrapperPass(
 /// A helper for the legacy pass manager to create a \c AAResults
 /// object populated to the best of our ability for a particular function when
 /// inside of a \c ModulePass or a \c CallGraphSCCPass.
+///
+/// If a \c ModulePass or a \c CallGraphSCCPass calls \p
+/// createLegacyPMAAResults, it also needs to call \p addUsedAAAnalyses in \p
+/// getAnalysisUsage.
 AAResults createLegacyPMAAResults(Pass &P, Function &F, BasicAAResult &BAR);
 
+/// A helper for the legacy pass manager to populate \p AU to add uses to make
+/// sure the analyses required by \p createLegacyPMAAResults are available.
+void getAAResultsAnalysisUsage(AnalysisUsage &AU);
+
 } // End llvm namespace
 
 #endif