8 files changed, 73 insertions, 12 deletions
diff --git a/include/llvm/Transforms/Scalar/NaryReassociate.h b/include/llvm/Transforms/Scalar/NaryReassociate.h
index a74bb6cc4194..f35707eeb3f0 100644
--- a/include/llvm/Transforms/Scalar/NaryReassociate.h
+++ b/include/llvm/Transforms/Scalar/NaryReassociate.h
@@ -167,7 +167,7 @@ private:
   //     foo(a + b);
   //   if (p2)
   //     bar(a + b);
-  DenseMap<const SCEV *, SmallVector<WeakVH, 2>> SeenExprs;
+  DenseMap<const SCEV *, SmallVector<WeakTrackingVH, 2>> SeenExprs;
 };
 } // namespace llvm
 
diff --git a/include/llvm/Transforms/Scalar/SimpleLoopUnswitch.h b/include/llvm/Transforms/Scalar/SimpleLoopUnswitch.h
new file mode 100644
index 000000000000..d7282ac6a781
--- /dev/null
+++ b/include/llvm/Transforms/Scalar/SimpleLoopUnswitch.h
@@ -0,0 +1,53 @@
+//===- SimpleLoopUnswitch.h - Hoist loop-invariant control flow -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_SCALAR_SIMPLELOOPUNSWITCH_H
+#define LLVM_TRANSFORMS_SCALAR_SIMPLELOOPUNSWITCH_H
+
+#include "llvm/Analysis/LoopAnalysisManager.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
+
+namespace llvm {
+
+/// This pass transforms loops that contain branches on loop-invariant
+/// conditions to have multiple loops. For example, it turns the left into the
+/// right code:
+///
+///  for (...)                  if (lic)
+///    A                          for (...)
+///    if (lic)                     A; B; C
+///      B                      else
+///    C                          for (...)
+///                                 A; C
+///
+/// This can increase the size of the code exponentially (doubling it every time
+/// a loop is unswitched) so we only unswitch if the resultant code will be
+/// smaller than a threshold.
+///
+/// This pass expects LICM to be run before it to hoist invariant conditions out
+/// of the loop, to make the unswitching opportunity obvious.
+///
+class SimpleLoopUnswitchPass : public PassInfoMixin<SimpleLoopUnswitchPass> {
+public:
+  SimpleLoopUnswitchPass() = default;
+
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
+};
+
+/// Create the legacy pass object for the simple loop unswitcher.
+///
+/// See the documentaion for `SimpleLoopUnswitchPass` for details.
+Pass *createSimpleLoopUnswitchLegacyPass();
+
+} // end namespace llvm
+
+#endif // LLVM_TRANSFORMS_SCALAR_SIMPLELOOPUNSWITCH_H
diff --git a/include/llvm/Transforms/Utils/Cloning.h b/include/llvm/Transforms/Utils/Cloning.h
index 337305a0a82c..0a8903a6ed7b 100644
--- a/include/llvm/Transforms/Utils/Cloning.h
+++ b/include/llvm/Transforms/Utils/Cloning.h
@@ -74,7 +74,7 @@ struct ClonedCodeInfo {
   /// All cloned call sites that have operand bundles attached are appended to
   /// this vector.  This vector may contain nulls or undefs if some of the
   /// originally inserted callsites were DCE'ed after they were cloned.
-  std::vector<WeakVH> OperandBundleCallSites;
+  std::vector<WeakTrackingVH> OperandBundleCallSites;
 
   ClonedCodeInfo() = default;
 };
@@ -192,7 +192,7 @@ public:
 
   /// InlinedCalls - InlineFunction fills this in with callsites that were
   /// inlined from the callee.  This is only filled in if CG is non-null.
-  SmallVector<WeakVH, 8> InlinedCalls;
+  SmallVector<WeakTrackingVH, 8> InlinedCalls;
 
   /// All of the new call sites inlined into the caller.
   ///
diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index 4933712fb8ad..b5a5f4c2704c 100644
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -286,9 +286,6 @@ DbgDeclareInst *FindAllocaDbgDeclare(Value *V);
 /// Finds the llvm.dbg.value intrinsics describing a value.
 void findDbgValues(SmallVectorImpl<DbgValueInst *> &DbgValues, Value *V);
 
-/// Constants for \p replaceDbgDeclare and friends.
-enum { NoDeref = false, WithDeref = true };
-
 /// Replaces llvm.dbg.declare instruction when the address it describes
 /// is replaced with a new value. If Deref is true, an additional DW_OP_deref is
 /// prepended to the expression. If Offset is non-zero, a constant displacement
diff --git a/include/llvm/Transforms/Utils/ModuleUtils.h b/include/llvm/Transforms/Utils/ModuleUtils.h
index f5e843e2e8b5..e9793fe4b666 100644
--- a/include/llvm/Transforms/Utils/ModuleUtils.h
+++ b/include/llvm/Transforms/Utils/ModuleUtils.h
@@ -84,6 +84,17 @@ void appendToCompilerUsed(Module &M, ArrayRef<GlobalValue *> Values);
 void filterDeadComdatFunctions(
     Module &M, SmallVectorImpl<Function *> &DeadComdatFunctions);
 
+/// \brief Produce a unique identifier for this module by taking the MD5 sum of
+/// the names of the module's strong external symbols.
+///
+/// This identifier is normally guaranteed to be unique, or the program would
+/// fail to link due to multiply defined symbols.
+///
+/// If the module has no strong external symbols (such a module may still have a
+/// semantic effect if it performs global initialization), we cannot produce a
+/// unique identifier for this module, so we return the empty string.
+std::string getUniqueModuleId(Module *M);
+
 } // End llvm namespace
 
 #endif //  LLVM_TRANSFORMS_UTILS_MODULEUTILS_H
diff --git a/include/llvm/Transforms/Utils/SimplifyIndVar.h b/include/llvm/Transforms/Utils/SimplifyIndVar.h
index 6cdeeeb60a65..8d50aeb10d6e 100644
--- a/include/llvm/Transforms/Utils/SimplifyIndVar.h
+++ b/include/llvm/Transforms/Utils/SimplifyIndVar.h
@@ -46,13 +46,13 @@ public:
 /// simplifyUsersOfIV - Simplify instructions that use this induction variable
 /// by using ScalarEvolution to analyze the IV's recurrence.
 bool simplifyUsersOfIV(PHINode *CurrIV, ScalarEvolution *SE, DominatorTree *DT,
-                       LoopInfo *LI, SmallVectorImpl<WeakVH> &Dead,
+                       LoopInfo *LI, SmallVectorImpl<WeakTrackingVH> &Dead,
                        IVVisitor *V = nullptr);
 
 /// SimplifyLoopIVs - Simplify users of induction variables within this
 /// loop. This does not actually change or add IVs.
 bool simplifyLoopIVs(Loop *L, ScalarEvolution *SE, DominatorTree *DT,
-                     LoopInfo *LI, SmallVectorImpl<WeakVH> &Dead);
+                     LoopInfo *LI, SmallVectorImpl<WeakTrackingVH> &Dead);
 
 } // end namespace llvm
 
diff --git a/include/llvm/Transforms/Utils/ValueMapper.h b/include/llvm/Transforms/Utils/ValueMapper.h
index 950ad92afcd7..e44dc437342d 100644
--- a/include/llvm/Transforms/Utils/ValueMapper.h
+++ b/include/llvm/Transforms/Utils/ValueMapper.h
@@ -23,7 +23,7 @@ namespace llvm {
 
 class Value;
 class Instruction;
-typedef ValueMap<const Value *, WeakVH> ValueToValueMapTy;
+typedef ValueMap<const Value *, WeakTrackingVH> ValueToValueMapTy;
 
 /// This is a class that can be implemented by clients to remap types when
 /// cloning constants and instructions.
diff --git a/include/llvm/Transforms/Vectorize/SLPVectorizer.h b/include/llvm/Transforms/Vectorize/SLPVectorizer.h
index d669a8e5b615..10338f7937e8 100644
--- a/include/llvm/Transforms/Vectorize/SLPVectorizer.h
+++ b/include/llvm/Transforms/Vectorize/SLPVectorizer.h
@@ -40,8 +40,8 @@ class BoUpSLP;
 struct SLPVectorizerPass : public PassInfoMixin<SLPVectorizerPass> {
   typedef SmallVector<StoreInst *, 8> StoreList;
   typedef MapVector<Value *, StoreList> StoreListMap;
-  typedef SmallVector<WeakVH, 8> WeakVHList;
-  typedef MapVector<Value *, WeakVHList> WeakVHListMap;
+  typedef SmallVector<WeakTrackingVH, 8> WeakTrackingVHList;
+  typedef MapVector<Value *, WeakTrackingVHList> WeakTrackingVHListMap;
 
   ScalarEvolution *SE = nullptr;
   TargetTransformInfo *TTI = nullptr;
@@ -111,7 +111,7 @@ private:
   StoreListMap Stores;
 
   /// The getelementptr instructions in a basic block organized by base pointer.
-  WeakVHListMap GEPs;
+  WeakTrackingVHListMap GEPs;
 };
 }