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, 42 deletions

diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 0eddd5ada7..ecb3229693 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -372,7 +372,7 @@ static Instruction *createMalloc(Instruction *InsertBefore,
   // Create the call to Malloc.
   BasicBlock* BB = InsertBefore ? InsertBefore->getParent() : InsertAtEnd;
   Module* M = BB->getParent()->getParent();
-  const Type *BPTy = Type::getInt8PtrTy(BB->getContext());
+  Type *BPTy = Type::getInt8PtrTy(BB->getContext());
   Value *MallocFunc = MallocF;
   if (!MallocFunc)
     // prototype malloc as "void *malloc(size_t)"
@@ -823,7 +823,7 @@ bool AllocaInst::isArrayAllocation() const {
   return true;
 }
 
-const Type *AllocaInst::getAllocatedType() const {
+Type *AllocaInst::getAllocatedType() const {
   return getType()->getElementType();
 }
 
@@ -1098,7 +1098,7 @@ GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
 GetElementPtrInst::GetElementPtrInst(Value *Ptr, Value *Idx,
                                      const Twine &Name, Instruction *InBe)
   : Instruction(PointerType::get(
-      checkType(getIndexedType(Ptr->getType(),Idx)), retrieveAddrSpace(Ptr)),
+      checkGEPType(getIndexedType(Ptr->getType(),Idx)), retrieveAddrSpace(Ptr)),
                 GetElementPtr,
                 OperandTraits<GetElementPtrInst>::op_end(this) - 2,
                 2, InBe) {
@@ -1108,7 +1108,7 @@ GetElementPtrInst::GetElementPtrInst(Value *Ptr, Value *Idx,
 GetElementPtrInst::GetElementPtrInst(Value *Ptr, Value *Idx,
                                      const Twine &Name, BasicBlock *IAE)
   : Instruction(PointerType::get(
-            checkType(getIndexedType(Ptr->getType(),Idx)),  
+            checkGEPType(getIndexedType(Ptr->getType(),Idx)),  
                 retrieveAddrSpace(Ptr)),
                 GetElementPtr,
                 OperandTraits<GetElementPtrInst>::op_end(this) - 2,
@@ -1126,60 +1126,50 @@ GetElementPtrInst::GetElementPtrInst(Value *Ptr, Value *Idx,
 /// pointer type.
 ///
 template <typename IndexTy>
-static const Type* getIndexedTypeInternal(const Type *Ptr, IndexTy const *Idxs,
-                                          unsigned NumIdx) {
+static Type *getIndexedTypeInternal(const Type *Ptr, IndexTy const *Idxs,
+                                    unsigned NumIdx) {
   const PointerType *PTy = dyn_cast<PointerType>(Ptr);
   if (!PTy) return 0;   // Type isn't a pointer type!
-  const Type *Agg = PTy->getElementType();
+  Type *Agg = PTy->getElementType();
 
   // Handle the special case of the empty set index set, which is always valid.
   if (NumIdx == 0)
     return Agg;
   
   // If there is at least one index, the top level type must be sized, otherwise
-  // it cannot be 'stepped over'.  We explicitly allow abstract types (those
-  // that contain opaque types) under the assumption that it will be resolved to
-  // a sane type later.
-  if (!Agg->isSized() && !Agg->isAbstract())
+  // it cannot be 'stepped over'.
+  if (!Agg->isSized())
     return 0;
 
   unsigned CurIdx = 1;
   for (; CurIdx != NumIdx; ++CurIdx) {
-    const CompositeType *CT = dyn_cast<CompositeType>(Agg);
+    CompositeType *CT = dyn_cast<CompositeType>(Agg);
     if (!CT || CT->isPointerTy()) return 0;
     IndexTy Index = Idxs[CurIdx];
     if (!CT->indexValid(Index)) return 0;
     Agg = CT->getTypeAtIndex(Index);
-
-    // If the new type forwards to another type, then it is in the middle
-    // of being refined to another type (and hence, may have dropped all
-    // references to what it was using before).  So, use the new forwarded
-    // type.
-    if (const Type *Ty = Agg->getForwardedType())
-      Agg = Ty;
   }
   return CurIdx == NumIdx ? Agg : 0;
 }
 
-const Type* GetElementPtrInst::getIndexedType(const Type *Ptr,
-                                              Value* const *Idxs,
-                                              unsigned NumIdx) {
+Type *GetElementPtrInst::getIndexedType(const Type *Ptr, Value* const *Idxs,
+                                        unsigned NumIdx) {
   return getIndexedTypeInternal(Ptr, Idxs, NumIdx);
 }
 
-const Type* GetElementPtrInst::getIndexedType(const Type *Ptr,
-                                              Constant* const *Idxs,
-                                              unsigned NumIdx) {
+Type *GetElementPtrInst::getIndexedType(const Type *Ptr,
+                                        Constant* const *Idxs,
+                                        unsigned NumIdx) {
   return getIndexedTypeInternal(Ptr, Idxs, NumIdx);
 }
 
-const Type* GetElementPtrInst::getIndexedType(const Type *Ptr,
-                                              uint64_t const *Idxs,
-                                              unsigned NumIdx) {
+Type *GetElementPtrInst::getIndexedType(const Type *Ptr,
+                                        uint64_t const *Idxs,
+                                        unsigned NumIdx) {
   return getIndexedTypeInternal(Ptr, Idxs, NumIdx);
 }
 
-const Type* GetElementPtrInst::getIndexedType(const Type *Ptr, Value *Idx) {
+Type *GetElementPtrInst::getIndexedType(const Type *Ptr, Value *Idx) {
   const PointerType *PTy = dyn_cast<PointerType>(Ptr);
   if (!PTy) return 0;   // Type isn't a pointer type!
 
@@ -1482,9 +1472,9 @@ ExtractValueInst::ExtractValueInst(const ExtractValueInst &EVI)
 // A null type is returned if the indices are invalid for the specified
 // pointer type.
 //
-const Type* ExtractValueInst::getIndexedType(const Type *Agg,
-                                             const unsigned *Idxs,
-                                             unsigned NumIdx) {
+Type *ExtractValueInst::getIndexedType(const Type *Agg,
+                                       const unsigned *Idxs,
+                                       unsigned NumIdx) {
   for (unsigned CurIdx = 0; CurIdx != NumIdx; ++CurIdx) {
     unsigned Index = Idxs[CurIdx];
     // We can't use CompositeType::indexValid(Index) here.
@@ -1505,19 +1495,11 @@ const Type* ExtractValueInst::getIndexedType(const Type *Agg,
     }
 
     Agg = cast<CompositeType>(Agg)->getTypeAtIndex(Index);
-
-    // If the new type forwards to another type, then it is in the middle
-    // of being refined to another type (and hence, may have dropped all
-    // references to what it was using before).  So, use the new forwarded
-    // type.
-    if (const Type *Ty = Agg->getForwardedType())
-      Agg = Ty;
   }
-  return Agg;
+  return const_cast<Type*>(Agg);
 }
 
-const Type* ExtractValueInst::getIndexedType(const Type *Agg,
-                                             unsigned Idx) {
+Type *ExtractValueInst::getIndexedType(const Type *Agg, unsigned Idx) {
   return getIndexedType(Agg, &Idx, 1);
 }