remove a bunch of locking from LLVMContextImpl. Since only one thread

can be banging on a context at a time, this isn't needed.  Owen, please
review.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85728 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 10 insertions, 89 deletions

diff --git a/include/llvm/TypeSymbolTable.h b/include/llvm/TypeSymbolTable.h
index 4dd3a4af2a..d84196f05e 100644
--- a/include/llvm/TypeSymbolTable.h
+++ b/include/llvm/TypeSymbolTable.h
@@ -15,6 +15,7 @@
 #define LLVM_TYPE_SYMBOL_TABLE_H
 
 #include "llvm/Type.h"
+#include "llvm/ADT/StringRef.h"
 #include <map>
 
 namespace llvm {
@@ -69,12 +70,16 @@ public:
   /// Lookup the type associated with name.
   /// @returns end() if the name is not found, or an iterator at the entry for
   /// Type.
-  iterator find(const StringRef &name);
+  iterator find(const StringRef &Name) {
+    return tmap.find(Name);
+  }
 
   /// Lookup the type associated with name.
   /// @returns end() if the name is not found, or an iterator at the entry for
   /// Type.
-  const_iterator find(const StringRef &name) const;
+  const_iterator find(const StringRef &Name) const {
+    return tmap.find(Name);
+  }
 
   /// @returns true iff the symbol table is empty.
   /// @brief Determine if the symbol table is empty
diff --git a/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index 29712b3c13..6a8148040d 100644
--- a/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -126,6 +126,9 @@ static bool MarkAliveBlocks(BasicBlock *BB,
         }
       }
       
+      // Store to undef and store to null are undefined and used to signal that
+      // they should be changed to unreachable by passes that can't modify the
+      // CFG.
       if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) {
         Value *Ptr = SI->getOperand(1);
         
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index e2e5396da5..000a063cc1 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -29,9 +29,6 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/GetElementPtrTypeIterator.h"
-#include "llvm/System/Mutex.h"
-#include "llvm/System/RWMutex.h"
-#include "llvm/System/Threading.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallVector.h"
 #include <algorithm>
diff --git a/lib/VMCore/ConstantsContext.h b/lib/VMCore/ConstantsContext.h
index 11fc802130..268a6602fa 100644
--- a/lib/VMCore/ConstantsContext.h
+++ b/lib/VMCore/ConstantsContext.h
@@ -20,8 +20,6 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/System/Mutex.h"
-#include "llvm/System/RWMutex.h"
 #include <map>
 
 namespace llvm {
@@ -529,12 +527,7 @@ private:
   ///
   AbstractTypeMapTy AbstractTypeMap;
     
-  /// ConstantUniqueMapLock - Mutex for this map.
-  sys::SmartMutex<true> ConstantUniqueMapLock;
-
 public:
-  // NOTE: This function is not locked.  It is the caller's responsibility
-  // to enforce proper synchronization.
   typename MapTy::iterator map_begin() { return Map.begin(); }
   typename MapTy::iterator map_end() { return Map.end(); }
 
@@ -551,8 +544,6 @@ public:
   /// entry and Exists=true.  If not, the iterator points to the newly
   /// inserted entry and returns Exists=false.  Newly inserted entries have
   /// I->second == 0, and should be filled in.
-  /// NOTE: This function is not locked.  It is the caller's responsibility
-  // to enforce proper synchronization.
   typename MapTy::iterator InsertOrGetItem(std::pair<MapKey, ConstantClass *>
                                  &InsertVal,
                                  bool &Exists) {
@@ -619,7 +610,6 @@ public:
   /// getOrCreate - Return the specified constant from the map, creating it if
   /// necessary.
   ConstantClass *getOrCreate(const TypeClass *Ty, const ValType &V) {
-    sys::SmartScopedLock<true> Lock(ConstantUniqueMapLock);
     MapKey Lookup(Ty, V);
     ConstantClass* Result = 0;
     
@@ -674,7 +664,6 @@ public:
   }
 
   void remove(ConstantClass *CP) {
-    sys::SmartScopedLock<true> Lock(ConstantUniqueMapLock);
     typename MapTy::iterator I = FindExistingElement(CP);
     assert(I != Map.end() && "Constant not found in constant table!");
     assert(I->second == CP && "Didn't find correct element?");
@@ -694,8 +683,6 @@ public:
   /// MoveConstantToNewSlot - If we are about to change C to be the element
   /// specified by I, update our internal data structures to reflect this
   /// fact.
-  /// NOTE: This function is not locked. It is the responsibility of the
-  /// caller to enforce proper synchronization if using this method.
   void MoveConstantToNewSlot(ConstantClass *C, typename MapTy::iterator I) {
     // First, remove the old location of the specified constant in the map.
     typename MapTy::iterator OldI = FindExistingElement(C);
@@ -725,7 +712,6 @@ public:
   }
     
   void refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
-    sys::SmartScopedLock<true> Lock(ConstantUniqueMapLock);
     typename AbstractTypeMapTy::iterator I = AbstractTypeMap.find(OldTy);
 
     assert(I != AbstractTypeMap.end() &&
diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index fd39b0c71b..1c3244ba4d 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -22,8 +22,6 @@
 #include "llvm/Metadata.h"
 #include "llvm/Constants.h"
 #include "llvm/DerivedTypes.h"
-#include "llvm/System/Mutex.h"
-#include "llvm/System/RWMutex.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
@@ -132,18 +130,8 @@ public:
   ConstantInt *TheTrueVal;
   ConstantInt *TheFalseVal;
   
-  // Lock used for guarding access to the leak detector
-  sys::SmartMutex<true> LLVMObjectsLock;
   LeakDetectorImpl<Value> LLVMObjects;
   
-  // Lock used for guarding access to the type maps.
-  sys::SmartMutex<true> TypeMapLock;
-  
-  // Recursive lock used for guarding access to AbstractTypeUsers.
-  // NOTE: The true template parameter means this will no-op when we're not in
-  // multithreaded mode.
-  sys::SmartMutex<true> AbstractTypeUsersLock;
-
   // Basic type instances.
   const Type VoidTy;
   const Type LabelTy;
diff --git a/lib/VMCore/LeakDetector.cpp b/lib/VMCore/LeakDetector.cpp
index 5ebd4f5ac0..a44f61d822 100644
--- a/lib/VMCore/LeakDetector.cpp
+++ b/lib/VMCore/LeakDetector.cpp
@@ -36,7 +36,6 @@ void LeakDetector::addGarbageObjectImpl(void *Object) {
 
 void LeakDetector::addGarbageObjectImpl(const Value *Object) {
   LLVMContextImpl *pImpl = Object->getContext().pImpl;
-  sys::SmartScopedLock<true> Lock(pImpl->LLVMObjectsLock);
   pImpl->LLVMObjects.addGarbage(Object);
 }
 
@@ -47,7 +46,6 @@ void LeakDetector::removeGarbageObjectImpl(void *Object) {
 
 void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
   LLVMContextImpl *pImpl = Object->getContext().pImpl;
-  sys::SmartScopedLock<true> Lock(pImpl->LLVMObjectsLock);
   pImpl->LLVMObjects.removeGarbage(Object);
 }
 
@@ -55,7 +53,6 @@ void LeakDetector::checkForGarbageImpl(LLVMContext &Context,
                                        const std::string &Message) {
   LLVMContextImpl *pImpl = Context.pImpl;
   sys::SmartScopedLock<true> Lock(*ObjectsLock);
-  sys::SmartScopedLock<true> CLock(pImpl->LLVMObjectsLock);
   
   Objects->setName("GENERIC");
   pImpl->LLVMObjects.setName("LLVM");
diff --git a/lib/VMCore/LeaksContext.h b/lib/VMCore/LeaksContext.h
index b0c3a14fe8..bd10a479ae 100644
--- a/lib/VMCore/LeaksContext.h
+++ b/lib/VMCore/LeaksContext.h
@@ -14,7 +14,6 @@
 
 #include "llvm/Value.h"
 #include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
 template <class T>
diff --git a/lib/VMCore/Type.cpp b/lib/VMCore/Type.cpp
index 7afbc682d1..739c463d91 100644
--- a/lib/VMCore/Type.cpp
+++ b/lib/VMCore/Type.cpp
@@ -27,8 +27,6 @@
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/System/Mutex.h"
-#include "llvm/System/RWMutex.h"
 #include "llvm/System/Threading.h"
 #include <algorithm>
 #include <cstdarg>
@@ -768,7 +766,6 @@ const IntegerType *IntegerType::get(LLVMContext &C, unsigned NumBits) {
   
   // First, see if the type is already in the table, for which
   // a reader lock suffices.
-  sys::SmartScopedLock<true> L(pImpl->TypeMapLock);
   ITy = pImpl->IntegerTypes.get(IVT);
     
   if (!ITy) {
@@ -810,7 +807,6 @@ FunctionType *FunctionType::get(const Type *ReturnType,
   
   LLVMContextImpl *pImpl = ReturnType->getContext().pImpl;
   
-  sys::SmartScopedLock<true> L(pImpl->TypeMapLock);
   FT = pImpl->FunctionTypes.get(VT);
   
   if (!FT) {
@@ -835,7 +831,6 @@ ArrayType *ArrayType::get(const Type *ElementType, uint64_t NumElements) {
 
   LLVMContextImpl *pImpl = ElementType->getContext().pImpl;
   
-  sys::SmartScopedLock<true> L(pImpl->TypeMapLock);
   AT = pImpl->ArrayTypes.get(AVT);
       
   if (!AT) {
@@ -861,7 +856,6 @@ VectorType *VectorType::get(const Type *ElementType, unsigned NumElements) {
   
   LLVMContextImpl *pImpl = ElementType->getContext().pImpl;
   
-  sys::SmartScopedLock<true> L(pImpl->TypeMapLock);
   PT = pImpl->VectorTypes.get(PVT);
     
   if (!PT) {
@@ -890,7 +884,6 @@ StructType *StructType::get(LLVMContext &Context,
   
   LLVMContextImpl *pImpl = Context.pImpl;
   
-  sys::SmartScopedLock<true> L(pImpl->TypeMapLock);
   ST = pImpl->StructTypes.get(STV);
     
   if (!ST) {
@@ -938,7 +931,6 @@ PointerType *PointerType::get(const Type *ValueType, unsigned AddressSpace) {
   
   LLVMContextImpl *pImpl = ValueType->getContext().pImpl;
   
-  sys::SmartScopedLock<true> L(pImpl->TypeMapLock);
   PT = pImpl->PointerTypes.get(PVT);
   
   if (!PT) {
@@ -970,10 +962,7 @@ bool PointerType::isValidElementType(const Type *ElemTy) {
 // it.  This function is called primarily by the PATypeHandle class.
 void Type::addAbstractTypeUser(AbstractTypeUser *U) const {
   assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!");
-  LLVMContextImpl *pImpl = getContext().pImpl;
-  pImpl->AbstractTypeUsersLock.acquire();
   AbstractTypeUsers.push_back(U);
-  pImpl->AbstractTypeUsersLock.release();
 }
 
 
@@ -983,8 +972,6 @@ void Type::addAbstractTypeUser(AbstractTypeUser *U) const {
 // is annihilated, because there is no way to get a reference to it ever again.
 //
 void Type::removeAbstractTypeUser(AbstractTypeUser *U) const {
-  LLVMContextImpl *pImpl = getContext().pImpl;
-  pImpl->AbstractTypeUsersLock.acquire();
   
   // Search from back to front because we will notify users from back to
   // front.  Also, it is likely that there will be a stack like behavior to
@@ -1013,7 +1000,6 @@ void Type::removeAbstractTypeUser(AbstractTypeUser *U) const {
   this->destroy();
   }
   
-  pImpl->AbstractTypeUsersLock.release();
 }
 
 // unlockedRefineAbstractTypeTo - This function is used when it is discovered
@@ -1065,7 +1051,6 @@ void DerivedType::unlockedRefineAbstractTypeTo(const Type *NewType) {
   // will not cause users to drop off of the use list.  If we resolve to ourself
   // we succeed!
   //
-  pImpl->AbstractTypeUsersLock.acquire();
   while (!AbstractTypeUsers.empty() && NewTy != this) {
     AbstractTypeUser *User = AbstractTypeUsers.back();
 
@@ -1081,7 +1066,6 @@ void DerivedType::unlockedRefineAbstractTypeTo(const Type *NewType) {
     assert(AbstractTypeUsers.size() != OldSize &&
            "AbsTyUser did not remove self from user list!");
   }
-  pImpl->AbstractTypeUsersLock.release();
 
   // If we were successful removing all users from the type, 'this' will be
   // deleted when the last PATypeHolder is destroyed or updated from this type.
@@ -1095,7 +1079,6 @@ void DerivedType::unlockedRefineAbstractTypeTo(const Type *NewType) {
 void DerivedType::refineAbstractTypeTo(const Type *NewType) {
   // All recursive calls will go through unlockedRefineAbstractTypeTo,
   // to avoid deadlock problems.
-  sys::SmartScopedLock<true> L(NewType->getContext().pImpl->TypeMapLock);
   unlockedRefineAbstractTypeTo(NewType);
 }
 
@@ -1107,9 +1090,6 @@ void DerivedType::notifyUsesThatTypeBecameConcrete() {
   DEBUG(errs() << "typeIsREFINED type: " << (void*)this << " " << *this <<"\n");
 #endif
 
-  LLVMContextImpl *pImpl = getContext().pImpl;
-
-  pImpl->AbstractTypeUsersLock.acquire();
   unsigned OldSize = AbstractTypeUsers.size(); OldSize=OldSize;
   while (!AbstractTypeUsers.empty()) {
     AbstractTypeUser *ATU = AbstractTypeUsers.back();
@@ -1118,7 +1098,6 @@ void DerivedType::notifyUsesThatTypeBecameConcrete() {
     assert(AbstractTypeUsers.size() < OldSize-- &&
            "AbstractTypeUser did not remove itself from the use list!");
   }
-  pImpl->AbstractTypeUsersLock.release();
 }
 
 // refineAbstractType - Called when a contained type is found to be more
diff --git a/lib/VMCore/TypeSymbolTable.cpp b/lib/VMCore/TypeSymbolTable.cpp
index f31ea6693e..3440a77946 100644
--- a/lib/VMCore/TypeSymbolTable.cpp
+++ b/lib/VMCore/TypeSymbolTable.cpp
@@ -17,16 +17,12 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/System/RWMutex.h"
-#include "llvm/System/Threading.h"
 #include <algorithm>
 using namespace llvm;
 
 #define DEBUG_SYMBOL_TABLE 0
 #define DEBUG_ABSTYPE 0
 
-static ManagedStatic<sys::SmartRWMutex<true> > TypeSymbolTableLock;
-
 TypeSymbolTable::~TypeSymbolTable() {
   // Drop all abstract type references in the type plane...
   for (iterator TI = tmap.begin(), TE = tmap.end(); TI != TE; ++TI) {
@@ -38,8 +34,6 @@ TypeSymbolTable::~TypeSymbolTable() {
 std::string TypeSymbolTable::getUniqueName(const StringRef &BaseName) const {
   std::string TryName = BaseName;
   
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);
-  
   const_iterator End = tmap.end();
 
   // See if the name exists
@@ -50,8 +44,6 @@ std::string TypeSymbolTable::getUniqueName(const StringRef &BaseName) const {
 
 // lookup a type by name - returns null on failure
 Type* TypeSymbolTable::lookup(const StringRef &Name) const {
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);
-  
   const_iterator TI = tmap.find(Name);
   Type* result = 0;
   if (TI != tmap.end())
@@ -59,21 +51,9 @@ Type* TypeSymbolTable::lookup(const StringRef &Name) const {
   return result;
 }
 
-TypeSymbolTable::iterator TypeSymbolTable::find(const StringRef &Name) {
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);  
-  return tmap.find(Name);
-}
-
-TypeSymbolTable::const_iterator
-TypeSymbolTable::find(const StringRef &Name) const {
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);  
-  return tmap.find(Name);
-}
 
 // remove - Remove a type from the symbol table...
 Type* TypeSymbolTable::remove(iterator Entry) {
-  TypeSymbolTableLock->writer_acquire();
-  
   assert(Entry != tmap.end() && "Invalid entry to remove!");
   const Type* Result = Entry->second;
 
@@ -84,8 +64,6 @@ Type* TypeSymbolTable::remove(iterator Entry) {
 
   tmap.erase(Entry);
   
-  TypeSymbolTableLock->writer_release();
-
   // If we are removing an abstract type, remove the symbol table from it's use
   // list...
   if (Result->isAbstract()) {
@@ -105,8 +83,6 @@ Type* TypeSymbolTable::remove(iterator Entry) {
 void TypeSymbolTable::insert(const StringRef &Name, const Type* T) {
   assert(T && "Can't insert null type into symbol table!");
 
-  TypeSymbolTableLock->writer_acquire();
-
   if (tmap.insert(std::make_pair(Name, T)).second) {
     // Type inserted fine with no conflict.
     
@@ -132,8 +108,6 @@ void TypeSymbolTable::insert(const StringRef &Name, const Type* T) {
     tmap.insert(make_pair(UniqueName, T));
   }
   
-  TypeSymbolTableLock->writer_release();
-
   // If we are adding an abstract type, add the symbol table to it's use list.
   if (T->isAbstract()) {
     cast<DerivedType>(T)->addAbstractTypeUser(this);
@@ -146,8 +120,6 @@ void TypeSymbolTable::insert(const StringRef &Name, const Type* T) {
 // This function is called when one of the types in the type plane are refined
 void TypeSymbolTable::refineAbstractType(const DerivedType *OldType,
                                          const Type *NewType) {
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);
-  
   // Loop over all of the types in the symbol table, replacing any references
   // to OldType with references to NewType.  Note that there may be multiple
   // occurrences, and although we only need to remove one at a time, it's
@@ -177,7 +149,6 @@ void TypeSymbolTable::typeBecameConcrete(const DerivedType *AbsTy) {
   // Loop over all of the types in the symbol table, dropping any abstract
   // type user entries for AbsTy which occur because there are names for the
   // type.
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);
   for (iterator TI = begin(), TE = end(); TI != TE; ++TI)
     if (TI->second == const_cast<Type*>(static_cast<const Type*>(AbsTy)))
       AbsTy->removeAbstractTypeUser(this);
@@ -191,8 +162,6 @@ static void DumpTypes(const std::pair<const std::string, const Type*>& T ) {
 
 void TypeSymbolTable::dump() const {
   errs() << "TypeSymbolPlane: ";
-  sys::SmartScopedReader<true> Reader(*TypeSymbolTableLock);
   for_each(tmap.begin(), tmap.end(), DumpTypes);
 }
 
-// vim: sw=2 ai
diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp
index 35ec9bef91..826e8a10b5 100644
--- a/lib/VMCore/Value.cpp
+++ b/lib/VMCore/Value.cpp
@@ -27,8 +27,6 @@
 #include "llvm/Support/LeakDetector.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/ValueHandle.h"
-#include "llvm/System/RWMutex.h"
-#include "llvm/System/Threading.h"
 #include "llvm/ADT/DenseMap.h"
 #include <algorithm>
 using namespace llvm;