Land the long talked about "type system rewrite" patch. This

patch brings numerous advantages to LLVM.  One way to look at it
is through diffstat:
 109 files changed, 3005 insertions(+), 5906 deletions(-)

Removing almost 3K lines of code is a good thing.  Other advantages
include:

1. Value::getType() is a simple load that can be CSE'd, not a mutating
   union-find operation.
2. Types a uniqued and never move once created, defining away PATypeHolder.
3. Structs can be "named" now, and their name is part of the identity that
   uniques them.  This means that the compiler doesn't merge them structurally
   which makes the IR much less confusing.
4. Now that there is no way to get a cycle in a type graph without a named
   struct type, "upreferences" go away.
5. Type refinement is completely gone, which should make LTO much MUCH faster
   in some common cases with C++ code.
6. Types are now generally immutable, so we can use "Type *" instead 
   "const Type *" everywhere.

Downsides of this patch are that it removes some functions from the C API,
so people using those will have to upgrade to (not yet added) new API.  
"LLVM 3.0" is the right time to do this.

There are still some cleanups pending after this, this patch is large enough
as-is.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134829 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 24 insertions, 52 deletions

diff --git a/include/llvm/Module.h b/include/llvm/Module.h
index aef8eb890f..47d23f36c1 100644
--- a/include/llvm/Module.h
+++ b/include/llvm/Module.h
@@ -28,6 +28,10 @@ namespace llvm {
 class FunctionType;
 class GVMaterializer;
 class LLVMContext;
+class StructType;
+template<typename T> struct DenseMapInfo;
+template<typename KeyT, typename ValueT, 
+         typename KeyInfoT, typename ValueInfoT> class DenseMap;
 
 template<> struct ilist_traits<Function>
   : public SymbolTableListTraits<Function, Module> {
@@ -145,7 +149,6 @@ private:
   NamedMDListType NamedMDList;    ///< The named metadata in the module
   std::string GlobalScopeAsm;     ///< Inline Asm at global scope.
   ValueSymbolTable *ValSymTab;    ///< Symbol table for values
-  TypeSymbolTable *TypeSymTab;    ///< Symbol table for types
   OwningPtr<GVMaterializer> Materializer;  ///< Used to materialize GlobalValues
   std::string ModuleID;           ///< Human readable identifier for the module
   std::string TargetTriple;       ///< Platform target triple Module compiled on
@@ -231,7 +234,7 @@ public:
 /// @name Generic Value Accessors
 /// @{
 
-  /// getNamedValue - Return the first global value in the module with
+  /// getNamedValue - Return the global value in the module with
   /// the specified name, of arbitrary type.  This method returns null
   /// if a global with the specified name is not found.
   GlobalValue *getNamedValue(StringRef Name) const;
@@ -244,6 +247,18 @@ public:
   /// custom metadata IDs registered in this LLVMContext.
   void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
 
+  
+  typedef DenseMap<StructType*, unsigned, DenseMapInfo<StructType*>,
+                   DenseMapInfo<unsigned> > NumeredTypesMapTy;
+
+  /// findUsedStructTypes - Walk the entire module and find all of the
+  /// struct types that are in use, returning them in a vector.
+  void findUsedStructTypes(std::vector<StructType*> &StructTypes) const;
+  
+  /// getTypeByName - Return the type with the specified name, or null if there
+  /// is none by that name.
+  StructType *getTypeByName(StringRef Name) const;
+
 /// @}
 /// @name Function Accessors
 /// @{
@@ -296,7 +311,7 @@ public:
   GlobalVariable *getGlobalVariable(StringRef Name,
                                     bool AllowInternal = false) const;
 
-  /// getNamedGlobal - Return the first global variable in the module with the
+  /// getNamedGlobal - Return the global variable in the module with the
   /// specified name, of arbitrary type.  This method returns null if a global
   /// with the specified name is not found.
   GlobalVariable *getNamedGlobal(StringRef Name) const {
@@ -316,7 +331,7 @@ public:
 /// @name Global Alias Accessors
 /// @{
 
-  /// getNamedAlias - Return the first global alias in the module with the
+  /// getNamedAlias - Return the global alias in the module with the
   /// specified name, of arbitrary type.  This method returns null if a global
   /// with the specified name is not found.
   GlobalAlias *getNamedAlias(StringRef Name) const;
@@ -325,12 +340,12 @@ public:
 /// @name Named Metadata Accessors
 /// @{
 
-  /// getNamedMetadata - Return the first NamedMDNode in the module with the
+  /// getNamedMetadata - Return the NamedMDNode in the module with the
   /// specified name. This method returns null if a NamedMDNode with the
   /// specified name is not found.
   NamedMDNode *getNamedMetadata(const Twine &Name) const;
 
-  /// getOrInsertNamedMetadata - Return the first named MDNode in the module
+  /// getOrInsertNamedMetadata - Return the named MDNode in the module
   /// with the specified name. This method returns a new NamedMDNode if a
   /// NamedMDNode with the specified name is not found.
   NamedMDNode *getOrInsertNamedMetadata(StringRef Name);
@@ -340,23 +355,6 @@ public:
   void eraseNamedMetadata(NamedMDNode *NMD);
 
 /// @}
-/// @name Type Accessors
-/// @{
-
-  /// addTypeName - Insert an entry in the symbol table mapping Str to Type.  If
-  /// there is already an entry for this name, true is returned and the symbol
-  /// table is not modified.
-  bool addTypeName(StringRef Name, const Type *Ty);
-
-  /// getTypeName - If there is at least one entry in the symbol table for the
-  /// specified type, return it.
-  std::string getTypeName(const Type *Ty) const;
-
-  /// getTypeByName - Return the type with the specified name in this module, or
-  /// null if there is none by that name.
-  const Type *getTypeByName(StringRef Name) const;
-
-/// @}
 /// @name Materialization
 /// @{
 
@@ -429,41 +427,26 @@ public:
   const ValueSymbolTable &getValueSymbolTable() const { return *ValSymTab; }
   /// Get the Module's symbol table of global variable and function identifiers.
   ValueSymbolTable       &getValueSymbolTable()       { return *ValSymTab; }
-  /// Get the symbol table of types
-  const TypeSymbolTable  &getTypeSymbolTable() const  { return *TypeSymTab; }
-  /// Get the Module's symbol table of types
-  TypeSymbolTable        &getTypeSymbolTable()        { return *TypeSymTab; }
 
 /// @}
 /// @name Global Variable Iteration
 /// @{
 
-  /// Get an iterator to the first global variable
   global_iterator       global_begin()       { return GlobalList.begin(); }
-  /// Get a constant iterator to the first global variable
   const_global_iterator global_begin() const { return GlobalList.begin(); }
-  /// Get an iterator to the last global variable
   global_iterator       global_end  ()       { return GlobalList.end(); }
-  /// Get a constant iterator to the last global variable
   const_global_iterator global_end  () const { return GlobalList.end(); }
-  /// Determine if the list of globals is empty.
   bool                  global_empty() const { return GlobalList.empty(); }
 
 /// @}
 /// @name Function Iteration
 /// @{
 
-  /// Get an iterator to the first function.
   iterator                begin()       { return FunctionList.begin(); }
-  /// Get a constant iterator to the first function.
   const_iterator          begin() const { return FunctionList.begin(); }
-  /// Get an iterator to the last function.
   iterator                end  ()       { return FunctionList.end();   }
-  /// Get a constant iterator to the last function.
   const_iterator          end  () const { return FunctionList.end();   }
-  /// Determine how many functions are in the Module's list of functions.
   size_t                  size() const  { return FunctionList.size(); }
-  /// Determine if the list of functions is empty.
   bool                    empty() const { return FunctionList.empty(); }
 
 /// @}
@@ -487,17 +470,11 @@ public:
 /// @name Alias Iteration
 /// @{
 
-  /// Get an iterator to the first alias.
   alias_iterator       alias_begin()            { return AliasList.begin(); }
-  /// Get a constant iterator to the first alias.
   const_alias_iterator alias_begin() const      { return AliasList.begin(); }
-  /// Get an iterator to the last alias.
   alias_iterator       alias_end  ()            { return AliasList.end();   }
-  /// Get a constant iterator to the last alias.
   const_alias_iterator alias_end  () const      { return AliasList.end();   }
-  /// Determine how many aliases are in the Module's list of aliases.
   size_t               alias_size () const      { return AliasList.size();  }
-  /// Determine if the list of aliases is empty.
   bool                 alias_empty() const      { return AliasList.empty(); }
 
 
@@ -505,24 +482,17 @@ public:
 /// @name Named Metadata Iteration
 /// @{
 
-  /// Get an iterator to the first named metadata.
   named_metadata_iterator named_metadata_begin() { return NamedMDList.begin(); }
-  /// Get a constant iterator to the first named metadata.
   const_named_metadata_iterator named_metadata_begin() const {
     return NamedMDList.begin();
   }
 
-  /// Get an iterator to the last named metadata.
   named_metadata_iterator named_metadata_end() { return NamedMDList.end(); }
-  /// Get a constant iterator to the last named metadata.
   const_named_metadata_iterator named_metadata_end() const {
     return NamedMDList.end();
   }
 
-  /// Determine how many NamedMDNodes are in the Module's list of named
-  /// metadata.
   size_t named_metadata_size() const { return NamedMDList.size();  }
-  /// Determine if the list of named metadata is empty.
   bool named_metadata_empty() const { return NamedMDList.empty(); }
 
 
@@ -530,11 +500,13 @@ public:
 /// @name Utility functions for printing and dumping Module objects
 /// @{
 
-  /// Print the module to an output stream with AssemblyAnnotationWriter.
+  /// Print the module to an output stream with an optional
+  /// AssemblyAnnotationWriter.
   void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW) const;
 
   /// Dump the module to stderr (for debugging).
   void dump() const;
+  
   /// This function causes all the subinstructions to "let go" of all references
   /// that they are maintaining.  This allows one to 'delete' a whole class at
   /// a time, even though there may be circular references... first all