Merge commit 'b3201c5cf1e183d840f7c99ff779d57f1549d8e5' into merge_20130226

Conflicts:
	include/llvm/Support/ELF.h
	lib/Support/DeltaAlgorithm.cpp

Change-Id: I24a4fbce62eb39d924efee3c687b55e1e17b30cd

1 files changed, 74 insertions, 0 deletions

diff --git a/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.h b/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.h
new file mode 100644
index 0000000..7abe995
--- /dev/null
+++ b/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.h
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+//===- ObjCARCAliasAnalysis.h - ObjC ARC Optimization -*- mode: c++ -*-----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares a simple ARC-aware AliasAnalysis using special knowledge
+/// of Objective C to enhance other optimization passes which rely on the Alias
+/// Analysis infrastructure.
+///
+/// WARNING: This file knows about certain library functions. It recognizes them
+/// by name, and hardwires knowledge of their semantics.
+///
+/// WARNING: This file knows about how certain Objective-C library functions are
+/// used. Naive LLVM IR transformations which would otherwise be
+/// behavior-preserving may break these assumptions.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H
+#define LLVM_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H
+
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Pass.h"
+
+namespace llvm {
+namespace objcarc {
+
+  /// \brief This is a simple alias analysis implementation that uses knowledge
+  /// of ARC constructs to answer queries.
+  ///
+  /// TODO: This class could be generalized to know about other ObjC-specific
+  /// tricks. Such as knowing that ivars in the non-fragile ABI are non-aliasing
+  /// even though their offsets are dynamic.
+  class ObjCARCAliasAnalysis : public ImmutablePass,
+                               public AliasAnalysis {
+  public:
+    static char ID; // Class identification, replacement for typeinfo
+    ObjCARCAliasAnalysis() : ImmutablePass(ID) {
+      initializeObjCARCAliasAnalysisPass(*PassRegistry::getPassRegistry());
+    }
+
+  private:
+    virtual void initializePass() {
+      InitializeAliasAnalysis(this);
+    }
+
+    /// This method is used when a pass implements an analysis interface through
+    /// multiple inheritance.  If needed, it should override this to adjust the
+    /// this pointer as needed for the specified pass info.
+    virtual void *getAdjustedAnalysisPointer(const void *PI) {
+      if (PI == &AliasAnalysis::ID)
+        return static_cast<AliasAnalysis *>(this);
+      return this;
+    }
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+    virtual AliasResult alias(const Location &LocA, const Location &LocB);
+    virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal);
+    virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS);
+    virtual ModRefBehavior getModRefBehavior(const Function *F);
+    virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
+                                       const Location &Loc);
+    virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
+                                       ImmutableCallSite CS2);
+  };
+
+} // namespace objcarc
+} // namespace llvm
+
+#endif // LLVM_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H