lib/VMCore/iMemory.cpp

   1 //===-- iMemory.cpp - Implement Memory instructions --------------*- C++ -*--=//
   2 //
   3 // This file implements the various memory related classes defined in iMemory.h
   4 //
   5 //===----------------------------------------------------------------------===//
   6
   7 #include "llvm/iMemory.h"
   8 #include "llvm/ConstPoolVals.h"
   9
  10 //===----------------------------------------------------------------------===//
  11 //                        MemAccessInst Implementation
  12 //===----------------------------------------------------------------------===//
  13
  14 // getIndexedType - Returns the type of the element that would be loaded with
  15 // a load instruction with the specified parameters.
  16 //
  17 // A null type is returned if the indices are invalid for the specified
  18 // pointer type.
  19 //
  20 const Type *MemAccessInst::getIndexedType(const Type *Ptr,
  21                                           const vector<ConstPoolVal*> &Idx,
  22                                           bool AllowStructLeaf = false) {
  23   if (!Ptr->isPointerType()) return 0;   // Type isn't a pointer type!
  24
  25   // Get the type pointed to...
  26   Ptr = ((const PointerType*)Ptr)->getValueType();
  27
  28   if (Ptr->isStructType()) {
  29     unsigned CurIDX = 0;
  30     while (Ptr->isStructType()) {
  31       if (Idx.size() == CurIDX)
  32         return AllowStructLeaf ? Ptr : 0;   // Can't load a whole structure!?!?
  33       if (Idx[CurIDX]->getType() != Type::UByteTy) return 0; // Illegal idx
  34       unsigned NextIdx = ((ConstPoolUInt*)Idx[CurIDX++])->getValue();
  35
  36       const StructType *ST = (const StructType *)Ptr;
  37       Ptr = ST->getElementTypes()[NextIdx];
  38     }
  39     return Ptr;
  40   } else if (Ptr->isArrayType()) {
  41     assert(0 && "Loading from arrays not implemented yet!");
  42   } else {
  43     return (Idx.size() == 0) ? Ptr : 0;  // Load directly through ptr
  44   }
  45 }
  46
  47
  48 //===----------------------------------------------------------------------===//
  49 //                           LoadInst Implementation
  50 //===----------------------------------------------------------------------===//
  51
  52 LoadInst::LoadInst(Value *Ptr, const vector<ConstPoolVal*> &Idx,
  53                    const string &Name = "")
  54   : MemAccessInst(getIndexedType(Ptr->getType(), Idx), Load, Name) {
  55   assert(getIndexedType(Ptr->getType(), Idx) && "Load operands invalid!");
  56   Operands.reserve(1+Idx.size());
  57   Operands.push_back(Use(Ptr, this));
  58
  59   for (unsigned i = 0, E = Idx.size(); i != E; ++i)
  60     Operands.push_back(Use(Idx[i], this));
  61 }
  62
  63
  64 //===----------------------------------------------------------------------===//
  65 //                           StoreInst Implementation
  66 //===----------------------------------------------------------------------===//
  67
  68 StoreInst::StoreInst(Value *Val, Value *Ptr, const vector<ConstPoolVal*> &Idx,
  69                      const string &Name = "")
  70   : MemAccessInst(Type::VoidTy, Store, Name) {
  71   assert(getIndexedType(Ptr->getType(), Idx) && "Store operands invalid!");
  72
  73   Operands.reserve(2+Idx.size());
  74   Operands.push_back(Use(Val, this));
  75   Operands.push_back(Use(Ptr, this));
  76
  77   for (unsigned i = 0, E = Idx.size(); i != E; ++i)
  78     Operands.push_back(Use(Idx[i], this));
  79 }
  80
  81
  82 //===----------------------------------------------------------------------===//
  83 //                       GetElementPtrInst Implementation
  84 //===----------------------------------------------------------------------===//
  85
  86 GetElementPtrInst::GetElementPtrInst(Value *Ptr,
  87                                      const vector<ConstPoolVal*> &Idx,
  88                                      const string &Name = "")
  89   : MemAccessInst(PointerType::getPointerType(getIndexedType(Ptr->getType(), Idx, true)), GetElementPtr, Name) {
  90   assert(getIndexedType(Ptr->getType(), Idx, true) && "gep operands invalid!");
  91   Operands.reserve(1+Idx.size());
  92   Operands.push_back(Use(Ptr, this));
  93
  94   for (unsigned i = 0, E = Idx.size(); i != E; ++i)
  95     Operands.push_back(Use(Idx[i], this));
  96 }
  97
  98 bool GetElementPtrInst::isStructSelector() const {
  99   return ((PointerType*)Operands[0]->getType())->getValueType()->isStructType();
 100 }