From: Daniel Berlin <dberlin@dberlin.org>
Date: Tue, 18 Mar 2008 22:22:53 +0000 (+0000)
Subject: Fix PR 2160 by making sure arguments to external functions get marked as pointing... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d3bf1aef3f1bfba362b71e72f416100a82d5b5db;p=oota-llvm.git

Fix PR 2160 by making sure arguments to external functions get marked as pointing to anything


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48509 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/IPA/Andersens.cpp b/lib/Analysis/IPA/Andersens.cpp
index a66a6faf1c5..49c6edd6207 100644
--- a/lib/Analysis/IPA/Andersens.cpp
+++ b/lib/Analysis/IPA/Andersens.cpp
@@ -647,9 +647,13 @@ Andersens::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
 
       if (N1->PointsTo->empty())
         return NoModRef;
-
+#if FULL_UNIVERSAL
+      if (!UniversalSet->PointsTo->test(FindNode(getNode(P))))
+        return NoModRef;  // Universal set does not contain P
+#else
       if (!N1->PointsTo->test(UniversalSet))
         return NoModRef;  // P doesn't point to the universal set.
+#endif
     }
 
   return AliasAnalysis::getModRefInfo(CS, P, Size);
@@ -1266,29 +1270,43 @@ void Andersens::AddConstraintsForCall(CallSite CS, Function *F) {
   }
 
   CallSite::arg_iterator ArgI = CS.arg_begin(), ArgE = CS.arg_end();
+  bool external = !F ||  F->isDeclaration();
   if (F) {
     // Direct Call
     Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
-    for (; AI != AE && ArgI != ArgE; ++AI, ++ArgI)
-      if (isa<PointerType>(AI->getType())) {
-        if (isa<PointerType>((*ArgI)->getType())) {
-          // Copy the actual argument into the formal argument.
-          Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
-                                           getNode(*ArgI)));
-        } else {
-          Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
-                                           UniversalSet));
-        }
-      } else if (isa<PointerType>((*ArgI)->getType())) {
+    for (; AI != AE && ArgI != ArgE; ++AI, ++ArgI) 
+      {
+#if !FULL_UNIVERSAL
+        if (external && isa<PointerType>((*ArgI)->getType())) 
+          {
+            // Add constraint that ArgI can now point to anything due to
+            // escaping, as can everything it points to. The second portion of
+            // this should be taken care of by universal = *universal
+            Constraints.push_back(Constraint(Constraint::Copy,
+                                             getNode(*ArgI),
+                                             UniversalSet));
+          }
+#endif
+        if (isa<PointerType>(AI->getType())) {
+          if (isa<PointerType>((*ArgI)->getType())) {
+            // Copy the actual argument into the formal argument.
+            Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
+                                             getNode(*ArgI)));
+          } else {
+            Constraints.push_back(Constraint(Constraint::Copy, getNode(AI),
+                                             UniversalSet));
+          }
+        } else if (isa<PointerType>((*ArgI)->getType())) {
 #if FULL_UNIVERSAL
-        Constraints.push_back(Constraint(Constraint::Copy,
-                                         UniversalSet,
-                                         getNode(*ArgI)));
+          Constraints.push_back(Constraint(Constraint::Copy,
+                                           UniversalSet,
+                                           getNode(*ArgI)));
 #else
-        Constraints.push_back(Constraint(Constraint::Copy,
-                                         getNode(*ArgI),
-                                         UniversalSet));
+          Constraints.push_back(Constraint(Constraint::Copy,
+                                           getNode(*ArgI),
+                                           UniversalSet));
 #endif
+        }
       }
   } else {
     //Indirect Call
diff --git a/test/Analysis/Andersens/modreftest2.ll b/test/Analysis/Andersens/modreftest2.ll
new file mode 100644
index 00000000000..2bb21673676
--- /dev/null
+++ b/test/Analysis/Andersens/modreftest2.ll
@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | opt -anders-aa -gvn | llvm-dis \  
+; RUN: | not grep {ret i32 undef}
+
+;; From PR 2160
+declare void @f(i32*)
+
+define i32 @g() {
+entry:
+      %tmp = alloca i32               ; <i32*> [#uses=2]
+	call void @f( i32* %tmp )
+	%tmp2 = load i32* %tmp          ; <i32> [#uses=1]
+	ret i32 %tmp2
+}
+