Initial checkin of TargetData code

llvm-svn: 384

1 files changed, 181 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetMachine/TargetData.cpp b/llvm/lib/CodeGen/TargetMachine/TargetData.cpp
new file mode 100644
index 00000000000..7ab0a6a2060
--- /dev/null
+++ b/llvm/lib/CodeGen/TargetMachine/TargetData.cpp
@@ -0,0 +1,181 @@
+//===-- TargetData.cpp - Data size & alignment routines --------------------==//
+//
+// This file defines target properties related to datatype size/offset/alignment
+// information.  It uses lazy annotations to cache information about how 
+// structure types are laid out and used.
+//
+// This structure should be created once, filled in if the defaults are not
+// correct and then passed around by const&.  None of the members functions
+// require modification to the object.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/TargetData.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/ConstPoolVals.h"
+
+static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
+			       unsigned &Size, unsigned char &Alignment);
+
+//===----------------------------------------------------------------------===//
+// Support for StructLayout Annotation
+//===----------------------------------------------------------------------===//
+
+StructLayout::StructLayout(const StructType *ST, const TargetData &TD) 
+  : Annotation(TD.getStructLayoutAID()) {
+  StructAlignment = 0;
+  StructSize = 0;
+
+  // Loop over each of the elements, placing them in memory...
+  for (StructType::ElementTypes::const_iterator
+	 TI = ST->getElementTypes().begin(), 
+	 TE = ST->getElementTypes().end(); TI != TE; ++TI) {
+    const Type *Ty = *TI;
+    unsigned char A;
+    unsigned TySize, TyAlign;
+    getTypeInfo(Ty, &TD, TySize, A);  TyAlign = A;
+
+    // Add padding if neccesary to make the data element aligned properly...
+    if (StructSize % TyAlign != 0)
+      StructSize = (StructSize/TyAlign + 1) * TyAlign;   // Add padding...
+
+    // Keep track of maximum alignment constraint
+    StructAlignment = max(TyAlign, StructAlignment);
+
+    MemberOffsets.push_back(StructSize);
+    StructSize += TySize;                 // Consume space for this data item...
+  }
+
+  // Add padding to the end of the struct so that it could be put in an array
+  // and all array elements would be aligned correctly.
+  if (StructSize % StructAlignment != 0)
+    StructSize = (StructSize/StructAlignment + 1) * StructAlignment;
+
+  if (StructSize == 0) {
+    StructSize = 1;           // Empty struct is 1 byte
+    StructAlignment = 1;
+  }
+}
+
+Annotation *TargetData::TypeAnFactory(AnnotationID AID, Annotable *T, void *D) {
+  const TargetData &TD = *(const TargetData*)D;
+  assert(AID == TD.AID && "Target data annotation ID mismatch!");
+  const Type *Ty = ((const Value *)T)->castTypeAsserting();
+  assert(Ty->isStructType() && 
+	 "Can only create StructLayout annotation on structs!");
+  return new StructLayout((const StructType *)Ty, TD);
+}
+
+//===----------------------------------------------------------------------===//
+//                       TargetData Class Implementation
+//===----------------------------------------------------------------------===//
+
+TargetData::TargetData(const string &TargetName, unsigned char PtrSize = 8,
+	     unsigned char PtrAl = 8, unsigned char DoubleAl = 8,
+	     unsigned char FloatAl = 4, unsigned char LongAl = 8, 
+	     unsigned char IntAl = 4, unsigned char ShortAl = 2,
+	     unsigned char ByteAl = 1)
+  : AID(AnnotationManager::getID("TargetData::" + TargetName)) {
+  AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
+
+  PointerSize      = PtrSize;
+  PointerAlignment = PtrAl;
+  DoubleAlignment  = DoubleAl;
+  FloatAlignment   = FloatAl;
+  LongAlignment    = LongAl;
+  IntAlignment     = IntAl;
+  ShortAlignment   = ShortAl;
+  ByteAlignment    = ByteAl;
+}
+
+TargetData::~TargetData() {
+  AnnotationManager::registerAnnotationFactory(AID, 0);   // Deregister factory
+}
+
+static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
+			       unsigned &Size, unsigned char &Alignment) {
+  switch (Ty->getPrimitiveID()) {
+  case Type::VoidTyID:
+  case Type::BoolTyID:
+  case Type::UByteTyID:
+  case Type::SByteTyID:  Size = 1; Alignment = TD->getByteAlignment(); return;
+  case Type::UShortTyID:
+  case Type::ShortTyID:  Size = 2; Alignment = TD->getShortAlignment(); return;
+  case Type::UIntTyID:
+  case Type::IntTyID:    Size = 4; Alignment = TD->getIntAlignment(); return;
+  case Type::ULongTyID:
+  case Type::LongTyID:   Size = 8; Alignment = TD->getLongAlignment(); return;
+  case Type::FloatTyID:  Size = 4; Alignment = TD->getFloatAlignment(); return;
+  case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleAlignment(); return;
+  case Type::LabelTyID:
+  case Type::PointerTyID:
+    Size = TD->getPointerSize(); Alignment = TD->getPointerAlignment();
+    return;
+  case Type::ArrayTyID: {
+    const ArrayType *ATy = (const ArrayType *)Ty;
+    assert(ATy->isSized() && "Can't get TypeInfo of an unsized array!");
+    getTypeInfo(ATy->getElementType(), TD, Size, Alignment);
+    Size *= ATy->getNumElements();
+    return;
+  }
+  case Type::StructTyID: {
+    // Get the layout annotation... which is lazily created on demand.
+    const StructLayout *Layout = TD->getStructLayout((const StructType*)Ty);
+    Size = Layout->StructSize; Alignment = Layout->StructAlignment;
+    return;
+  }
+    
+  case Type::TypeTyID:
+  default:
+    assert(0 && "Bad type for getTypeInfo!!!");
+    return;
+  }
+}
+
+unsigned TargetData::getTypeSize(const Type *Ty) const {
+  unsigned Size; unsigned char Align;
+  getTypeInfo(Ty, this, Size, Align);
+  return Size;
+}
+
+unsigned char TargetData::getTypeAlignment(const Type *Ty) const {
+  unsigned Size; unsigned char Align;
+  getTypeInfo(Ty, this, Size, Align);
+  return Align;
+}
+
+unsigned TargetData::getIndexedOffset(const Type *ptrTy,
+				      const vector<ConstPoolVal*> &Idx) const {
+  const PointerType *PtrTy = PtrTy->isPointerType();   // Returns null if not
+  assert(PtrTy && "getIndexedOffset on nonpointer!");
+
+  unsigned Result = 0;
+
+  // Get the type pointed to...
+  const Type *Ty = PtrTy->getValueType();
+
+  for (unsigned CurIDX = 0; CurIDX < Idx.size(); ++CurIDX) {
+    if (const StructType *STy = Ty->isStructType()) {
+      assert(Idx[CurIDX]->getType() == Type::UByteTy && "Illegal struct idx");
+      unsigned FieldNo = ((ConstPoolUInt*)Idx[CurIDX++])->getValue();
+
+      // Get structure layout information...
+      const StructLayout *Layout = getStructLayout(STy);
+
+      // Add in the offset, as calculated by the structure layout info...
+      assert(FieldNo < Layout->MemberOffsets.size() && "FieldNo out of range!");
+      Result += Layout->MemberOffsets[FieldNo];
+      
+      // Update Ty to refer to current element
+      Ty = STy->getElementTypes()[FieldNo];
+
+    } else if (const ArrayType *ATy = Ty->isArrayType()) {
+      assert(0 && "Loading from arrays not implemented yet!");
+    } else {
+      assert(0 && "Indexing type that is not struct or array?");
+      return 0;                         // Load directly through ptr
+    }
+  }
+
+  return Result;
+}