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 //                           LoadInst Implementation
  49 //===----------------------------------------------------------------------===//
  50
  51 LoadInst::LoadInst(Value *Ptr, const vector<ConstPoolVal*> &Idx,
  52                    const string &Name = "")
  53   : MemAccessInst(getIndexedType(Ptr->getType(), Idx), Load, Idx, Name) {
  54   assert(getIndexedType(Ptr->getType(), Idx) && "Load operands invalid!");
  55   Operands.reserve(1+Idx.size());
  56   Operands.push_back(Use(Ptr, this));
  57
  58   for (unsigned i = 0, E = Idx.size(); i != E; ++i)
  59     Operands.push_back(Use(Idx[i], this));
  60
  61 }
  62
  63 LoadInst::LoadInst(Value *Ptr, const string &Name = "")
  64   : MemAccessInst(cast<PointerType>(Ptr->getType())->getValueType(),
  65                   Load, vector<ConstPoolVal*>(), Name) {
  66   Operands.reserve(1);
  67   Operands.push_back(Use(Ptr, this));
  68 }
  69
  70
  71 //===----------------------------------------------------------------------===//
  72 //                           StoreInst Implementation
  73 //===----------------------------------------------------------------------===//
  74
  75 StoreInst::StoreInst(Value *Val, Value *Ptr, const vector<ConstPoolVal*> &Idx,
  76                      const string &Name = "")
  77   : MemAccessInst(Type::VoidTy, Store, Idx, Name) {
  78   assert(getIndexedType(Ptr->getType(), Idx) && "Store operands invalid!");
  79
  80   Operands.reserve(2+Idx.size());
  81   Operands.push_back(Use(Val, this));
  82   Operands.push_back(Use(Ptr, this));
  83
  84   for (unsigned i = 0, E = Idx.size(); i != E; ++i)
  85     Operands.push_back(Use(Idx[i], this));
  86 }
  87
  88 StoreInst::StoreInst(Value *Val, Value *Ptr, const string &Name = "")
  89   : MemAccessInst(Type::VoidTy, Store, vector<ConstPoolVal*>(), Name) {
  90
  91   Operands.reserve(2);
  92   Operands.push_back(Use(Val, this));
  93   Operands.push_back(Use(Ptr, this));
  94 }
  95
  96
  97 //===----------------------------------------------------------------------===//
  98 //                       GetElementPtrInst Implementation
  99 //===----------------------------------------------------------------------===//
 100
 101 GetElementPtrInst::GetElementPtrInst(Value *Ptr,
 102                                      const vector<ConstPoolVal*> &Idx,
 103                                      const string &Name = "")
 104   : MemAccessInst(PointerType::get(getIndexedType(Ptr->getType(), Idx, true)),
 105                   GetElementPtr, Idx, Name) {
 106   assert(getIndexedType(Ptr->getType(), Idx, true) && "gep operands invalid!");
 107   Operands.reserve(1+Idx.size());
 108   Operands.push_back(Use(Ptr, this));
 109
 110   for (unsigned i = 0, E = Idx.size(); i != E; ++i)
 111     Operands.push_back(Use(Idx[i], this));
 112 }
 113
 114 bool GetElementPtrInst::isStructSelector() const {
 115   return ((PointerType*)Operands[0]->getType())->getValueType()->isStructType();
 116 }