llvm-project/llvm/lib/Transforms/Utils/ValueMapper.cpp

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6.7 KiB
C++

//===- ValueMapper.cpp - Interface shared by lib/Transforms/Utils ---------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the MapValue function, which is shared by various parts of
// the lib/Transforms/Utils library.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/ValueMapper.h"
#include "llvm/Type.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/Metadata.h"
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM,
bool ModuleLevelChanges) {
TrackingVH<Value> &VMSlot = VM[V];
if (VMSlot) return VMSlot; // Does it exist in the map yet?
// NOTE: VMSlot can be invalidated by any reference to VM, which can grow the
// DenseMap. This includes any recursive calls to MapValue.
// Global values do not need to be seeded into the VM if they
// are using the identity mapping.
if (isa<GlobalValue>(V) || isa<InlineAsm>(V) || isa<MDString>(V) ||
(isa<MDNode>(V) && !cast<MDNode>(V)->isFunctionLocal() &&
!ModuleLevelChanges))
return VMSlot = const_cast<Value*>(V);
if (const MDNode *MD = dyn_cast<MDNode>(V)) {
// Start by assuming that we'll use the identity mapping.
VMSlot = const_cast<Value*>(V);
// Check all operands to see if any need to be remapped.
for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) {
Value *OP = MD->getOperand(i);
if (!OP || MapValue(OP, VM, ModuleLevelChanges) == OP) continue;
// Ok, at least one operand needs remapping.
MDNode *Dummy = MDNode::getTemporary(V->getContext(), 0, 0);
VM[V] = Dummy;
SmallVector<Value*, 4> Elts;
Elts.reserve(MD->getNumOperands());
for (i = 0; i != e; ++i)
Elts.push_back(MD->getOperand(i) ?
MapValue(MD->getOperand(i), VM, ModuleLevelChanges) : 0);
MDNode *NewMD = MDNode::get(V->getContext(), Elts.data(), Elts.size());
Dummy->replaceAllUsesWith(NewMD);
MDNode::deleteTemporary(Dummy);
return VM[V] = NewMD;
}
// No operands needed remapping; keep the identity map.
return const_cast<Value*>(V);
}
Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V));
if (C == 0)
return 0;
if (isa<ConstantInt>(C) || isa<ConstantFP>(C) ||
isa<ConstantPointerNull>(C) || isa<ConstantAggregateZero>(C) ||
isa<UndefValue>(C))
return VMSlot = C; // Primitive constants map directly
if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
for (User::op_iterator b = CA->op_begin(), i = b, e = CA->op_end();
i != e; ++i) {
Value *MV = MapValue(*i, VM, ModuleLevelChanges);
if (MV != *i) {
// This array must contain a reference to a global, make a new array
// and return it.
//
std::vector<Constant*> Values;
Values.reserve(CA->getNumOperands());
for (User::op_iterator j = b; j != i; ++j)
Values.push_back(cast<Constant>(*j));
Values.push_back(cast<Constant>(MV));
for (++i; i != e; ++i)
Values.push_back(cast<Constant>(MapValue(*i, VM,
ModuleLevelChanges)));
return VM[V] = ConstantArray::get(CA->getType(), Values);
}
}
return VM[V] = C;
}
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
for (User::op_iterator b = CS->op_begin(), i = b, e = CS->op_end();
i != e; ++i) {
Value *MV = MapValue(*i, VM, ModuleLevelChanges);
if (MV != *i) {
// This struct must contain a reference to a global, make a new struct
// and return it.
//
std::vector<Constant*> Values;
Values.reserve(CS->getNumOperands());
for (User::op_iterator j = b; j != i; ++j)
Values.push_back(cast<Constant>(*j));
Values.push_back(cast<Constant>(MV));
for (++i; i != e; ++i)
Values.push_back(cast<Constant>(MapValue(*i, VM,
ModuleLevelChanges)));
return VM[V] = ConstantStruct::get(CS->getType(), Values);
}
}
return VM[V] = C;
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
std::vector<Constant*> Ops;
for (User::op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i)
Ops.push_back(cast<Constant>(MapValue(*i, VM, ModuleLevelChanges)));
return VM[V] = CE->getWithOperands(Ops);
}
if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
for (User::op_iterator b = CV->op_begin(), i = b, e = CV->op_end();
i != e; ++i) {
Value *MV = MapValue(*i, VM, ModuleLevelChanges);
if (MV != *i) {
// This vector value must contain a reference to a global, make a new
// vector constant and return it.
//
std::vector<Constant*> Values;
Values.reserve(CV->getNumOperands());
for (User::op_iterator j = b; j != i; ++j)
Values.push_back(cast<Constant>(*j));
Values.push_back(cast<Constant>(MV));
for (++i; i != e; ++i)
Values.push_back(cast<Constant>(MapValue(*i, VM,
ModuleLevelChanges)));
return VM[V] = ConstantVector::get(Values);
}
}
return VM[V] = C;
}
BlockAddress *BA = cast<BlockAddress>(C);
Function *F = cast<Function>(MapValue(BA->getFunction(), VM,
ModuleLevelChanges));
BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM,
ModuleLevelChanges));
return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
}
/// RemapInstruction - Convert the instruction operands from referencing the
/// current values into those specified by VMap.
///
void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &VMap,
bool ModuleLevelChanges) {
// Remap operands.
for (User::op_iterator op = I->op_begin(), E = I->op_end(); op != E; ++op) {
Value *V = MapValue(*op, VMap, ModuleLevelChanges);
assert(V && "Referenced value not in value map!");
*op = V;
}
// Remap attached metadata.
SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
I->getAllMetadata(MDs);
for (SmallVectorImpl<std::pair<unsigned, MDNode *> >::iterator
MI = MDs.begin(), ME = MDs.end(); MI != ME; ++MI) {
Value *Old = MI->second;
Value *New = MapValue(Old, VMap, ModuleLevelChanges);
if (New != Old)
I->setMetadata(MI->first, cast<MDNode>(New));
}
}