ValueMapper.cpp revision 186b3d260643de5db63c4bab15beceb9edaee396
1//===- ValueMapper.cpp - Interface shared by lib/Transforms/Utils ---------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines the MapValue function, which is shared by various parts of 11// the lib/Transforms/Utils library. 12// 13//===----------------------------------------------------------------------===// 14 15#include "ValueMapper.h" 16#include "llvm/Type.h" 17#include "llvm/Constants.h" 18#include "llvm/Function.h" 19#include "llvm/Metadata.h" 20#include "llvm/ADT/SmallVector.h" 21using namespace llvm; 22 23Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM) { 24 ValueToValueMapTy::iterator VMI = VM.find(V); 25 if (VMI != VM.end()) 26 return VMI->second; // Does it exist in the map yet? 27 28 // Global values, metadata strings and inline asm do not need to be seeded into 29 // the ValueMap if they are using the identity mapping. 30 if (isa<GlobalValue>(V) || isa<InlineAsm>(V) || isa<MDString>(V)) { 31 VM.insert(std::make_pair(V, const_cast<Value*>(V))); 32 return const_cast<Value*>(V); 33 } 34 35 if (const MDNode *MD = dyn_cast<MDNode>(V)) { 36 // Insert a place holder in map to handle mdnode cycles. 37 Value *TmpV = MDString::get(V->getContext(), 38 std::string("llvm.md.clone.tmp." + VM.size())); 39 VM.insert(std::make_pair(V, MDNode::get(V->getContext(), &TmpV, 1))); 40 41 bool ReuseMD = true; 42 SmallVector<Value*, 4> Elts; 43 // If metadata element is mapped to a new value then seed metadata 44 // in the map. 45 for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) { 46 if (!MD->getOperand(i)) 47 Elts.push_back(0); 48 else { 49 Value *MappedOp = MapValue(MD->getOperand(i), VM); 50 if (MappedOp != MD->getOperand(i)) 51 ReuseMD = false; 52 Elts.push_back(MappedOp); 53 } 54 } 55 if (ReuseMD) { 56 VM.insert(std::make_pair(V, const_cast<Value*>(V))); 57 return const_cast<Value*>(V); 58 } 59 MDNode *NewMD = MDNode::get(V->getContext(), Elts.data(), Elts.size()); 60 VM.insert(std::make_pair(V, NewMD)); 61 return NewMD; 62 } 63 64 Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V)); 65 if (C == 0) return 0; 66 67 if (isa<ConstantInt>(C) || isa<ConstantFP>(C) || 68 isa<ConstantPointerNull>(C) || isa<ConstantAggregateZero>(C) || 69 isa<UndefValue>(C) || isa<MDString>(C)) 70 return VM[V] = C; // Primitive constants map directly 71 72 if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) { 73 for (User::op_iterator b = CA->op_begin(), i = b, e = CA->op_end(); 74 i != e; ++i) { 75 Value *MV = MapValue(*i, VM); 76 if (MV != *i) { 77 // This array must contain a reference to a global, make a new array 78 // and return it. 79 // 80 std::vector<Constant*> Values; 81 Values.reserve(CA->getNumOperands()); 82 for (User::op_iterator j = b; j != i; ++j) 83 Values.push_back(cast<Constant>(*j)); 84 Values.push_back(cast<Constant>(MV)); 85 for (++i; i != e; ++i) 86 Values.push_back(cast<Constant>(MapValue(*i, VM))); 87 return VM[V] = ConstantArray::get(CA->getType(), Values); 88 } 89 } 90 return VM[V] = C; 91 } 92 93 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) { 94 for (User::op_iterator b = CS->op_begin(), i = b, e = CS->op_end(); 95 i != e; ++i) { 96 Value *MV = MapValue(*i, VM); 97 if (MV != *i) { 98 // This struct must contain a reference to a global, make a new struct 99 // and return it. 100 // 101 std::vector<Constant*> Values; 102 Values.reserve(CS->getNumOperands()); 103 for (User::op_iterator j = b; j != i; ++j) 104 Values.push_back(cast<Constant>(*j)); 105 Values.push_back(cast<Constant>(MV)); 106 for (++i; i != e; ++i) 107 Values.push_back(cast<Constant>(MapValue(*i, VM))); 108 return VM[V] = ConstantStruct::get(CS->getType(), Values); 109 } 110 } 111 return VM[V] = C; 112 } 113 114 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) { 115 std::vector<Constant*> Ops; 116 for (User::op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i) 117 Ops.push_back(cast<Constant>(MapValue(*i, VM))); 118 return VM[V] = CE->getWithOperands(Ops); 119 } 120 121 if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) { 122 for (User::op_iterator b = CV->op_begin(), i = b, e = CV->op_end(); 123 i != e; ++i) { 124 Value *MV = MapValue(*i, VM); 125 if (MV != *i) { 126 // This vector value must contain a reference to a global, make a new 127 // vector constant and return it. 128 // 129 std::vector<Constant*> Values; 130 Values.reserve(CV->getNumOperands()); 131 for (User::op_iterator j = b; j != i; ++j) 132 Values.push_back(cast<Constant>(*j)); 133 Values.push_back(cast<Constant>(MV)); 134 for (++i; i != e; ++i) 135 Values.push_back(cast<Constant>(MapValue(*i, VM))); 136 return VM[V] = ConstantVector::get(Values); 137 } 138 } 139 return VM[V] = C; 140 } 141 142 BlockAddress *BA = cast<BlockAddress>(C); 143 Function *F = cast<Function>(MapValue(BA->getFunction(), VM)); 144 BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM)); 145 return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock()); 146} 147 148/// RemapInstruction - Convert the instruction operands from referencing the 149/// current values into those specified by ValueMap. 150/// 151void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &ValueMap) { 152 for (User::op_iterator op = I->op_begin(), E = I->op_end(); op != E; ++op) { 153 Value *V = MapValue(*op, ValueMap); 154 assert(V && "Referenced value not in value map!"); 155 *op = V; 156 } 157} 158 159