Refactor my previous change to maintain the distinction between AliasAnalysis and BasicAliasAnalysis. This involves some wider changes because it

folds away some never-used methods.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63900 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 84 insertions, 88 deletions

diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index 3e46fccc58..3d1b20bba7 100644
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -59,13 +59,6 @@ bool AliasAnalysis::pointsToConstantMemory(const Value *P) {
   return AA->pointsToConstantMemory(P);
 }
 
-AliasAnalysis::ModRefBehavior
-AliasAnalysis::getModRefBehavior(Function *F, CallSite CS,
-                                 std::vector<PointerAccessInfo> *Info) {
-  assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!");
-  return AA->getModRefBehavior(F, CS, Info);
-}
-
 bool AliasAnalysis::hasNoModRefInfoForCalls() const {
   assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!");
   return AA->hasNoModRefInfoForCalls();
@@ -115,33 +108,10 @@ AliasAnalysis::getModRefInfo(StoreInst *S, Value *P, unsigned Size) {
 AliasAnalysis::ModRefBehavior
 AliasAnalysis::getModRefBehavior(CallSite CS,
                                  std::vector<PointerAccessInfo> *Info) {
-  if (IntrinsicInst* II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
-    switch (II->getIntrinsicID()) {
-      case Intrinsic::atomic_cmp_swap:
-      case Intrinsic::atomic_load_add:
-      case Intrinsic::atomic_load_and:
-      case Intrinsic::atomic_load_max:
-      case Intrinsic::atomic_load_min:
-      case Intrinsic::atomic_load_nand:
-      case Intrinsic::atomic_load_or:
-      case Intrinsic::atomic_load_sub:
-      case Intrinsic::atomic_load_umax:
-      case Intrinsic::atomic_load_umin:
-      case Intrinsic::atomic_load_xor:
-      case Intrinsic::atomic_swap:
-        // CAS and related intrinsics only access their arguments.
-        return AliasAnalysis::AccessesArguments;
-      default:
-        break;
-    }
-  }
-  
   if (CS.doesNotAccessMemory())
     // Can't do better than this.
     return DoesNotAccessMemory;
-  ModRefBehavior MRB = UnknownModRefBehavior;
-  if (Function *F = CS.getCalledFunction())
-    MRB = getModRefBehavior(F, CS, Info);
+  ModRefBehavior MRB = getModRefBehavior(CS.getCalledFunction(), Info);
   if (MRB != DoesNotAccessMemory && CS.onlyReadsMemory())
     return OnlyReadsMemory;
   return MRB;
@@ -150,34 +120,10 @@ AliasAnalysis::getModRefBehavior(CallSite CS,
 AliasAnalysis::ModRefBehavior
 AliasAnalysis::getModRefBehavior(Function *F,
                                  std::vector<PointerAccessInfo> *Info) {
-  if (F->isIntrinsic()) {
-    switch (F->getIntrinsicID()) {
-      case Intrinsic::atomic_cmp_swap:
-      case Intrinsic::atomic_load_add:
-      case Intrinsic::atomic_load_and:
-      case Intrinsic::atomic_load_max:
-      case Intrinsic::atomic_load_min:
-      case Intrinsic::atomic_load_nand:
-      case Intrinsic::atomic_load_or:
-      case Intrinsic::atomic_load_sub:
-      case Intrinsic::atomic_load_umax:
-      case Intrinsic::atomic_load_umin:
-      case Intrinsic::atomic_load_xor:
-      case Intrinsic::atomic_swap:
-        // CAS and related intrinsics only access their arguments.
-        return AliasAnalysis::AccessesArguments;
-      default:
-        break;
-    }
-  }
-
   if (F->doesNotAccessMemory())
     // Can't do better than this.
     return DoesNotAccessMemory;
-  ModRefBehavior MRB = getModRefBehavior(F, CallSite(), Info);
-  if (MRB != DoesNotAccessMemory && F->onlyReadsMemory())
-    return OnlyReadsMemory;
-  return MRB;
+  return UnknownModRefBehavior;
 }
 
 AliasAnalysis::ModRefResult
@@ -188,6 +134,18 @@ AliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
     Mask = Ref;
   else if (MRB == DoesNotAccessMemory)
     return NoModRef;
+  else if (MRB == AliasAnalysis::AccessesArguments) {
+    bool doesAlias = false;
+    for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
+         AI != AE; ++AI)
+      if (alias(*AI, ~0U, P, Size) != NoAlias) {
+        doesAlias = true;
+        break;
+      }
+    
+    if (!doesAlias)
+      return NoModRef;
+  }
 
   if (!AA) return Mask;
 
diff --git a/lib/Analysis/AliasDebugger.cpp b/lib/Analysis/AliasDebugger.cpp
index 0bbd739351..1e82621e02 100644
--- a/lib/Analysis/AliasDebugger.cpp
+++ b/lib/Analysis/AliasDebugger.cpp
@@ -102,15 +102,6 @@ namespace {
       return AliasAnalysis::pointsToConstantMemory(P);
     }
 
-    /// getModRefBehavior - Return the behavior of the specified function if
-    /// called from the specified call site.  The call site may be null in which
-    /// case the most generic behavior of this function should be returned.
-    virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
-                                         std::vector<PointerAccessInfo> *Info) {
-      assert(Vals.find(F) != Vals.end() && "Never seen value in AA before");
-      return AliasAnalysis::getModRefBehavior(F, CS, Info);
-    }
-
     virtual void deleteValue(Value *V) {
       assert(Vals.find(V) != Vals.end() && "Never seen value in AA before");
       AliasAnalysis::deleteValue(V);
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 317e9d9e2e..1b26dc421c 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -155,11 +155,6 @@ namespace {
       return MayAlias;
     }
 
-    virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
-                                         std::vector<PointerAccessInfo> *Info) {
-      return UnknownModRefBehavior;
-    }
-
     virtual void getArgumentAccesses(Function *F, CallSite CS,
                                      std::vector<PointerAccessInfo> &Info) {
       assert(0 && "This method may not be called on this function!");
@@ -207,6 +202,12 @@ namespace {
     ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
     ModRefResult getModRefInfo(CallSite CS1, CallSite CS2);
     
+    virtual ModRefBehavior getModRefBehavior(CallSite CS,
+                                     std::vector<PointerAccessInfo> *Info = 0);
+
+    virtual ModRefBehavior getModRefBehavior(Function *F,
+                                     std::vector<PointerAccessInfo> *Info = 0);
+    
     /// hasNoModRefInfoForCalls - We can provide mod/ref information against
     /// non-escaping allocations.
     virtual bool hasNoModRefInfoForCalls() const { return false; }
@@ -249,6 +250,52 @@ bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) {
   return false;
 }
 
+
+static bool isAtomicRMW(Function* F) {
+  if (!F) return false;
+  if (F->isIntrinsic()) {
+    switch (F->getIntrinsicID()) {
+      case Intrinsic::atomic_cmp_swap:
+      case Intrinsic::atomic_load_add:
+      case Intrinsic::atomic_load_and:
+      case Intrinsic::atomic_load_max:
+      case Intrinsic::atomic_load_min:
+      case Intrinsic::atomic_load_nand:
+      case Intrinsic::atomic_load_or:
+      case Intrinsic::atomic_load_sub:
+      case Intrinsic::atomic_load_umax:
+      case Intrinsic::atomic_load_umin:
+      case Intrinsic::atomic_load_xor:
+      case Intrinsic::atomic_swap:
+        return true;
+      default:
+        return false;
+    }
+  }
+  
+  return false;
+}
+
+AliasAnalysis::ModRefBehavior
+BasicAliasAnalysis::getModRefBehavior(CallSite CS,
+                                 std::vector<PointerAccessInfo> *Info) {
+  if (isAtomicRMW(CS.getCalledFunction()))
+    // CAS and related intrinsics only access their arguments.
+    return AliasAnalysis::AccessesArguments;
+  
+  return AliasAnalysis::getModRefBehavior(CS, Info);
+}
+
+AliasAnalysis::ModRefBehavior
+BasicAliasAnalysis::getModRefBehavior(Function *F,
+                                 std::vector<PointerAccessInfo> *Info) {
+  if (isAtomicRMW(F))
+    // CAS and related intrinsics only access their arguments.
+    return AliasAnalysis::AccessesArguments;
+
+  return AliasAnalysis::getModRefBehavior(F, Info);
+}
+
 // getModRefInfo - Check to see if the specified callsite can clobber the
 // specified memory object.  Since we only look at local properties of this
 // function, we really can't say much about this query.  We do, however, use
@@ -256,22 +303,6 @@ bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) {
 //
 AliasAnalysis::ModRefResult
 BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
-  // If the function only accesses its arguments, it suffices to check that
-  // P does not alias any of those arguments.
-  if (AliasAnalysis::getModRefBehavior(CS, 0) ==
-      AliasAnalysis::AccessesArguments) {
-    bool doesAlias = false;
-    for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
-         AI != AE; ++AI)
-      if (alias(*AI, ~0U, P, Size) != NoAlias) {
-        doesAlias = true;
-        break;
-      }
-    
-    if (!doesAlias)
-      return NoModRef;
-  }
-  
   if (!isa<Constant>(P)) {
     const Value *Object = P->getUnderlyingObject();
     
diff --git a/lib/Analysis/IPA/GlobalsModRef.cpp b/lib/Analysis/IPA/GlobalsModRef.cpp
index a795ca675f..2e9884aa01 100644
--- a/lib/Analysis/IPA/GlobalsModRef.cpp
+++ b/lib/Analysis/IPA/GlobalsModRef.cpp
@@ -117,7 +117,7 @@ namespace {
     /// getModRefBehavior - Return the behavior of the specified function if
     /// called from the specified call site.  The call site may be null in which
     /// case the most generic behavior of this function should be returned.
-    virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
+    ModRefBehavior getModRefBehavior(Function *F,
                                          std::vector<PointerAccessInfo> *Info) {
       if (FunctionRecord *FR = getFunctionInfo(F)) {
         if (FR->FunctionEffect == 0)
@@ -125,7 +125,23 @@ namespace {
         else if ((FR->FunctionEffect & Mod) == 0)
           return OnlyReadsMemory;
       }
-      return AliasAnalysis::getModRefBehavior(F, CS, Info);
+      return AliasAnalysis::getModRefBehavior(F, Info);
+    }
+    
+    /// getModRefBehavior - Return the behavior of the specified function if
+    /// called from the specified call site.  The call site may be null in which
+    /// case the most generic behavior of this function should be returned.
+    ModRefBehavior getModRefBehavior(CallSite CS,
+                                         std::vector<PointerAccessInfo> *Info) {
+      Function* F = CS.getCalledFunction();
+      if (!F) return AliasAnalysis::getModRefBehavior(CS, Info);
+      if (FunctionRecord *FR = getFunctionInfo(F)) {
+        if (FR->FunctionEffect == 0)
+          return DoesNotAccessMemory;
+        else if ((FR->FunctionEffect & Mod) == 0)
+          return OnlyReadsMemory;
+      }
+      return AliasAnalysis::getModRefBehavior(CS, Info);
     }
 
     virtual void deleteValue(Value *V);