5 files changed, 62 insertions, 5 deletions
diff --git a/include/llvm/Support/BranchProbability.h b/include/llvm/Support/BranchProbability.h
index e8eb50d53eb60..b403d7fbf117d 100644
--- a/include/llvm/Support/BranchProbability.h
+++ b/include/llvm/Support/BranchProbability.h
@@ -112,6 +112,13 @@ public:
     return *this;
   }
 
+  BranchProbability &operator*=(uint32_t RHS) {
+    assert(N != UnknownN &&
+           "Unknown probability cannot participate in arithmetics.");
+    N = (uint64_t(N) * RHS > D) ? D : N * RHS;
+    return *this;
+  }
+
   BranchProbability &operator/=(uint32_t RHS) {
     assert(N != UnknownN &&
            "Unknown probability cannot participate in arithmetics.");
@@ -135,6 +142,11 @@ public:
     return Prob *= RHS;
   }
 
+  BranchProbability operator*(uint32_t RHS) const {
+    BranchProbability Prob(*this);
+    return Prob *= RHS;
+  }
+
   BranchProbability operator/(uint32_t RHS) const {
     BranchProbability Prob(*this);
     return Prob /= RHS;
diff --git a/include/llvm/Support/FileSystem.h b/include/llvm/Support/FileSystem.h
index 29515c231bc46..e3c5de7fbe642 100644
--- a/include/llvm/Support/FileSystem.h
+++ b/include/llvm/Support/FileSystem.h
@@ -116,7 +116,9 @@ inline perms &operator&=(perms &l, perms r) {
   return l;
 }
 inline perms operator~(perms x) {
-  return static_cast<perms>(~static_cast<unsigned short>(x));
+  // Avoid UB by explicitly truncating the (unsigned) ~ result.
+  return static_cast<perms>(
+      static_cast<unsigned short>(~static_cast<unsigned short>(x)));
 }
 
 class UniqueID {
diff --git a/include/llvm/Support/GenericDomTree.h b/include/llvm/Support/GenericDomTree.h
index eb7c27d2ffa5b..851ff7d80403f 100644
--- a/include/llvm/Support/GenericDomTree.h
+++ b/include/llvm/Support/GenericDomTree.h
@@ -286,13 +286,13 @@ protected:
     NodeRef NewBBSucc = *GraphT::child_begin(NewBB);
 
     std::vector<NodeRef> PredBlocks;
-    for (const auto Pred : children<Inverse<N>>(NewBB))
+    for (const auto &Pred : children<Inverse<N>>(NewBB))
       PredBlocks.push_back(Pred);
 
     assert(!PredBlocks.empty() && "No predblocks?");
 
     bool NewBBDominatesNewBBSucc = true;
-    for (const auto Pred : children<Inverse<N>>(NewBBSucc)) {
+    for (const auto &Pred : children<Inverse<N>>(NewBBSucc)) {
       if (Pred != NewBB && !dominates(NewBBSucc, Pred) &&
           isReachableFromEntry(Pred)) {
         NewBBDominatesNewBBSucc = false;
diff --git a/include/llvm/Support/KnownBits.h b/include/llvm/Support/KnownBits.h
new file mode 100644
index 0000000000000..08d4dedd0ac82
--- /dev/null
+++ b/include/llvm/Support/KnownBits.h
@@ -0,0 +1,43 @@
+//===- llvm/Support/KnownBits.h - Stores known zeros/ones -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a class for representing known zeros and ones used by
+// computeKnownBits.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_KNOWNBITS_H
+#define LLVM_SUPPORT_KNOWNBITS_H
+
+#include "llvm/ADT/APInt.h"
+
+namespace llvm {
+
+// For now this is a simple wrapper around two APInts.
+struct KnownBits {
+  APInt Zero;
+  APInt One;
+
+  // Default construct Zero and One.
+  KnownBits() {}
+
+  /// Create a known bits object of BitWidth bits initialized to unknown.
+  KnownBits(unsigned BitWidth) : Zero(BitWidth, 0), One(BitWidth, 0) {}
+
+  /// Get the bit width of this value.
+  unsigned getBitWidth() const {
+    assert(Zero.getBitWidth() == One.getBitWidth() &&
+           "Zero and One should have the same width!");
+    return Zero.getBitWidth();
+  }
+};
+
+} // end namespace llvm
+
+#endif
diff --git a/include/llvm/Support/YAMLTraits.h b/include/llvm/Support/YAMLTraits.h
index 6d02e4aba48a7..ffea679fab828 100644
--- a/include/llvm/Support/YAMLTraits.h
+++ b/include/llvm/Support/YAMLTraits.h
@@ -606,7 +606,7 @@ public:
   template <typename T>
   void bitSetCase(T &Val, const char* Str, const T ConstVal) {
     if ( bitSetMatch(Str, outputting() && (Val & ConstVal) == ConstVal) ) {
-      Val = Val | ConstVal;
+      Val = static_cast<T>(Val | ConstVal);
     }
   }
 
@@ -614,7 +614,7 @@ public:
   template <typename T>
   void bitSetCase(T &Val, const char* Str, const uint32_t ConstVal) {
     if ( bitSetMatch(Str, outputting() && (Val & ConstVal) == ConstVal) ) {
-      Val = Val | ConstVal;
+      Val = static_cast<T>(Val | ConstVal);
     }
   }