Merge commit '7dfcb84fc16b3bf6b2379713b53090757f0a45f9'

Conflicts:
	docs/LangRef.rst
	include/llvm/CodeGen/CallingConvLower.h
	include/llvm/IRReader/IRReader.h
	include/llvm/Target/TargetMachine.h
	lib/CodeGen/CallingConvLower.cpp
	lib/IRReader/IRReader.cpp
	lib/IRReader/LLVMBuild.txt
	lib/IRReader/Makefile
	lib/LLVMBuild.txt
	lib/Makefile
	lib/Support/MemoryBuffer.cpp
	lib/Support/Unix/PathV2.inc
	lib/Target/ARM/ARMBaseInstrInfo.cpp
	lib/Target/ARM/ARMISelLowering.cpp
	lib/Target/ARM/ARMInstrInfo.td
	lib/Target/ARM/ARMSubtarget.cpp
	lib/Target/ARM/ARMTargetMachine.cpp
	lib/Target/Mips/CMakeLists.txt
	lib/Target/Mips/MipsDelaySlotFiller.cpp
	lib/Target/Mips/MipsISelLowering.cpp
	lib/Target/Mips/MipsInstrInfo.td
	lib/Target/Mips/MipsSubtarget.cpp
	lib/Target/Mips/MipsSubtarget.h
	lib/Target/X86/X86FastISel.cpp
	lib/Target/X86/X86ISelDAGToDAG.cpp
	lib/Target/X86/X86ISelLowering.cpp
	lib/Target/X86/X86InstrControl.td
	lib/Target/X86/X86InstrFormats.td
	lib/Transforms/IPO/ExtractGV.cpp
	lib/Transforms/InstCombine/InstCombineCompares.cpp
	lib/Transforms/Utils/SimplifyLibCalls.cpp
	test/CodeGen/X86/fast-isel-divrem.ll
	test/MC/ARM/data-in-code.ll
	tools/Makefile
	tools/llvm-extract/llvm-extract.cpp
	tools/llvm-link/CMakeLists.txt
	tools/opt/CMakeLists.txt
	tools/opt/LLVMBuild.txt
	tools/opt/Makefile
	tools/opt/opt.cpp

1 files changed, 13 insertions, 2 deletions

diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index fce6513a97..4e75904ded 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -122,6 +122,9 @@ static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call",
 static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern",
        cl::desc("poison uninitialized stack variables with the given patter"),
        cl::Hidden, cl::init(0xff));
+static cl::opt<bool> ClPoisonUndef("msan-poison-undef",
+       cl::desc("poison undef temps"),
+       cl::Hidden, cl::init(true));
 
 static cl::opt<bool> ClHandleICmp("msan-handle-icmp",
        cl::desc("propagate shadow through ICmpEQ and ICmpNE"),
@@ -690,7 +693,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
   ///
   /// Clean shadow (all zeroes) means all bits of the value are defined
   /// (initialized).
-  Value *getCleanShadow(Value *V) {
+  Constant *getCleanShadow(Value *V) {
     Type *ShadowTy = getShadowTy(V);
     if (!ShadowTy)
       return 0;
@@ -709,6 +712,14 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     return ConstantStruct::get(ST, Vals);
   }
 
+  /// \brief Create a dirty shadow for a given value.
+  Constant *getPoisonedShadow(Value *V) {
+    Type *ShadowTy = getShadowTy(V);
+    if (!ShadowTy)
+      return 0;
+    return getPoisonedShadow(ShadowTy);
+  }
+
   /// \brief Create a clean (zero) origin.
   Value *getCleanOrigin() {
     return Constant::getNullValue(MS.OriginTy);
@@ -730,7 +741,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
       return Shadow;
     }
     if (UndefValue *U = dyn_cast<UndefValue>(V)) {
-      Value *AllOnes = getPoisonedShadow(getShadowTy(V));
+      Value *AllOnes = ClPoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V);
       DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n");
       (void)U;
       return AllOnes;