diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 0775cf4a224..afa6a4b5e67 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -392,7 +392,7 @@ bool AddressSanitizer::HasDynamicInitializer(GlobalVariable *G) {
 }
 
 void AddressSanitizer::instrumentMop(AsanFunctionContext &AFC, Instruction *I) {
-  bool IsWrite;
+  bool IsWrite = false;
   Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
   assert(Addr);
   if (ClOpt && ClOptGlobals) {
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index e7b5bc779a3..091d63d67db 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1796,7 +1796,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) {
       continue;
 
     // Determine if the two branches share a common destination.
-    Instruction::BinaryOps Opc;
+    Instruction::BinaryOps Opc = Instruction::BinaryOpsEnd;
     bool InvertPredCond = false;
 
     if (BI->isConditional()) {
diff --git a/utils/yaml2obj/yaml2obj.cpp b/utils/yaml2obj/yaml2obj.cpp
index c3b3e5499cd..4fc620f4ea9 100644
--- a/utils/yaml2obj/yaml2obj.cpp
+++ b/utils/yaml2obj/yaml2obj.cpp
@@ -148,7 +148,7 @@ struct COFFParser {
           return false;
         }
         if (KeyValue == "Machine") {
-          uint16_t Machine;
+          uint16_t Machine = COFF::MT_Invalid;
           if (!getAs(Value, Machine)) {
             // It's not a raw number, try matching the string.
             StringRef ValueValue = Value->getValue(Storage);