lib/Transforms/Utils/ValueMapper.cpp - llvm - Git at Google

 //===- 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/Constants.h"
 #include "llvm/Function.h"
 #include "llvm/InlineAsm.h"
 #include "llvm/Instructions.h"
 #include "llvm/Metadata.h"
 using namespace llvm;

 // Out of line method to get vtable etc for class.
 void ValueMapTypeRemapper::Anchor() {}

 Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM, RemapFlags Flags,
                       ValueMapTypeRemapper *TypeMapper) {
   ValueToValueMapTy::iterator I = VM.find(V);

   // If the value already exists in the map, use it.
   if (I != VM.end() && I->second) return I->second;

   // Global values do not need to be seeded into the VM if they
   // are using the identity mapping.
   if (isa<GlobalValue>(V) || isa<MDString>(V))
     return VM[V] = const_cast<Value*>(V);

   if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
     // Inline asm may need *type* remapping.
     FunctionType *NewTy = IA->getFunctionType();
     if (TypeMapper) {
       NewTy = cast<FunctionType>(TypeMapper->remapType(NewTy));

       if (NewTy != IA->getFunctionType())
         V = InlineAsm::get(NewTy, IA->getAsmString(), IA->getConstraintString(),
                            IA->hasSideEffects(), IA->isAlignStack());
     }

     return VM[V] = const_cast<Value*>(V);
   }


   if (const MDNode *MD = dyn_cast<MDNode>(V)) {
     // If this is a module-level metadata and we know that nothing at the module
     // level is changing, then use an identity mapping.
     if (!MD->isFunctionLocal() && (Flags & RF_NoModuleLevelChanges))
       return VM[V] = const_cast<Value*>(V);

     // Create a dummy node in case we have a metadata cycle.
     MDNode *Dummy = MDNode::getTemporary(V->getContext(), ArrayRef<Value*>());
     VM[V] = Dummy;

     // 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 == 0 || MapValue(OP, VM, Flags, TypeMapper) == OP) continue;

       // Ok, at least one operand needs remapping.
       SmallVector<Value*, 4> Elts;
       Elts.reserve(MD->getNumOperands());
       for (i = 0; i != e; ++i) {
         Value *Op = MD->getOperand(i);
         Elts.push_back(Op ? MapValue(Op, VM, Flags, TypeMapper) : 0);
       }
       MDNode *NewMD = MDNode::get(V->getContext(), Elts);
       Dummy->replaceAllUsesWith(NewMD);
       VM[V] = NewMD;
       MDNode::deleteTemporary(Dummy);
       return NewMD;
     }

     VM[V] = const_cast<Value*>(V);
     MDNode::deleteTemporary(Dummy);

     // No operands needed remapping.  Use an identity mapping.
     return const_cast<Value*>(V);
   }

   // Okay, this either must be a constant (which may or may not be mappable) or
   // is something that is not in the mapping table.
   Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V));
   if (C == 0)
     return 0;

   if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
     Function *F =
       cast<Function>(MapValue(BA->getFunction(), VM, Flags, TypeMapper));
     BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(), VM,
                                                        Flags, TypeMapper));
     return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
   }

   // Otherwise, we have some other constant to remap.  Start by checking to see
   // if all operands have an identity remapping.
   unsigned OpNo = 0, NumOperands = C->getNumOperands();
   Value *Mapped = 0;
   for (; OpNo != NumOperands; ++OpNo) {
     Value *Op = C->getOperand(OpNo);
     Mapped = MapValue(Op, VM, Flags, TypeMapper);
     if (Mapped != C) break;
   }

   // See if the type mapper wants to remap the type as well.
   Type *NewTy = C->getType();
   if (TypeMapper)
     NewTy = TypeMapper->remapType(NewTy);

   // If the result type and all operands match up, then just insert an identity
   // mapping.
   if (OpNo == NumOperands && NewTy == C->getType())
     return VM[V] = C;

   // Okay, we need to create a new constant.  We've already processed some or
   // all of the operands, set them all up now.
   SmallVector<Constant*, 8> Ops;
   Ops.reserve(NumOperands);
   for (unsigned j = 0; j != OpNo; ++j)
     Ops.push_back(cast<Constant>(C->getOperand(j)));

   // If one of the operands mismatch, push it and the other mapped operands.
   if (OpNo != NumOperands) {
     Ops.push_back(cast<Constant>(Mapped));

     // Map the rest of the operands that aren't processed yet.
     for (++OpNo; OpNo != NumOperands; ++OpNo)
       Ops.push_back(MapValue(cast<Constant>(C->getOperand(OpNo)), VM,
                              Flags, TypeMapper));
   }

   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
     return VM[V] = CE->getWithOperands(Ops, NewTy);
   if (isa<ConstantArray>(C))
     return VM[V] = ConstantArray::get(cast<ArrayType>(NewTy), Ops);
   if (isa<ConstantStruct>(C))
     return VM[V] = ConstantStruct::get(cast<StructType>(NewTy), Ops);
   if (isa<ConstantVector>(C))
     return VM[V] = ConstantVector::get(Ops);
   // If this is a no-operand constant, it must be because the type was remapped.
   if (isa<UndefValue>(C))
     return VM[V] = UndefValue::get(NewTy);
   if (isa<ConstantAggregateZero>(C))
     return VM[V] = ConstantAggregateZero::get(NewTy);
   assert(isa<ConstantPointerNull>(C));
   return VM[V] = ConstantPointerNull::get(cast<PointerType>(NewTy));
 }

 /// RemapInstruction - Convert the instruction operands from referencing the
 /// current values into those specified by VMap.
 ///
 void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &VMap,
                             RemapFlags Flags, ValueMapTypeRemapper *TypeMapper){
   // Remap operands.
   for (User::op_iterator op = I->op_begin(), E = I->op_end(); op != E; ++op) {
     Value *V = MapValue(*op, VMap, Flags, TypeMapper);
     // If we aren't ignoring missing entries, assert that something happened.
     if (V != 0)
       *op = V;
     else
       assert((Flags & RF_IgnoreMissingEntries) &&
              "Referenced value not in value map!");
   }

   // Remap phi nodes' incoming blocks.
   if (PHINode *PN = dyn_cast<PHINode>(I)) {
     for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
       Value *V = MapValue(PN->getIncomingBlock(i), VMap, Flags);
       // If we aren't ignoring missing entries, assert that something happened.
       if (V != 0)
         PN->setIncomingBlock(i, cast<BasicBlock>(V));
       else
         assert((Flags & RF_IgnoreMissingEntries) &&
                "Referenced block not in value map!");
     }
   }

   // 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) {
     MDNode *Old = MI->second;
     MDNode *New = MapValue(Old, VMap, Flags, TypeMapper);
     if (New != Old)
       I->setMetadata(MI->first, New);
   }

   // If the instruction's type is being remapped, do so now.
   if (TypeMapper)
     I->mutateType(TypeMapper->remapType(I->getType()));
 }
	//===- 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/Constants.h"
	#include "llvm/Function.h"
	#include "llvm/InlineAsm.h"
	#include "llvm/Instructions.h"
	#include "llvm/Metadata.h"
	using namespace llvm;

	// Out of line method to get vtable etc for class.
	void ValueMapTypeRemapper::Anchor() {}

	Value llvm::MapValue(const Value V, ValueToValueMapTy &VM, RemapFlags Flags,
	ValueMapTypeRemapper *TypeMapper) {
	ValueToValueMapTy::iterator I = VM.find(V);

	// If the value already exists in the map, use it.
	if (I != VM.end() && I->second) return I->second;

	// Global values do not need to be seeded into the VM if they
	// are using the identity mapping.
	if (isa<GlobalValue>(V) \|\| isa<MDString>(V))
	return VM[V] = const_cast<Value*>(V);

	if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
	// Inline asm may need type remapping.
	FunctionType *NewTy = IA->getFunctionType();
	if (TypeMapper) {
	NewTy = cast<FunctionType>(TypeMapper->remapType(NewTy));

	if (NewTy != IA->getFunctionType())
	V = InlineAsm::get(NewTy, IA->getAsmString(), IA->getConstraintString(),
	IA->hasSideEffects(), IA->isAlignStack());
	}

	return VM[V] = const_cast<Value*>(V);
	}


	if (const MDNode *MD = dyn_cast<MDNode>(V)) {
	// If this is a module-level metadata and we know that nothing at the module
	// level is changing, then use an identity mapping.
	if (!MD->isFunctionLocal() && (Flags & RF_NoModuleLevelChanges))
	return VM[V] = const_cast<Value*>(V);

	// Create a dummy node in case we have a metadata cycle.
	MDNode Dummy = MDNode::getTemporary(V->getContext(), ArrayRef<Value>());
	VM[V] = Dummy;

	// 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 == 0 \|\| MapValue(OP, VM, Flags, TypeMapper) == OP) continue;

	// Ok, at least one operand needs remapping.
	SmallVector<Value*, 4> Elts;
	Elts.reserve(MD->getNumOperands());
	for (i = 0; i != e; ++i) {
	Value *Op = MD->getOperand(i);
	Elts.push_back(Op ? MapValue(Op, VM, Flags, TypeMapper) : 0);
	}
	MDNode *NewMD = MDNode::get(V->getContext(), Elts);
	Dummy->replaceAllUsesWith(NewMD);
	VM[V] = NewMD;
	MDNode::deleteTemporary(Dummy);
	return NewMD;
	}

	VM[V] = const_cast<Value*>(V);
	MDNode::deleteTemporary(Dummy);

	// No operands needed remapping. Use an identity mapping.
	return const_cast<Value*>(V);
	}

	// Okay, this either must be a constant (which may or may not be mappable) or
	// is something that is not in the mapping table.
	Constant C = const_cast<Constant>(dyn_cast<Constant>(V));
	if (C == 0)
	return 0;

	if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
	Function *F =
	cast<Function>(MapValue(BA->getFunction(), VM, Flags, TypeMapper));
	BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(), VM,
	Flags, TypeMapper));
	return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
	}

	// Otherwise, we have some other constant to remap. Start by checking to see
	// if all operands have an identity remapping.
	unsigned OpNo = 0, NumOperands = C->getNumOperands();
	Value *Mapped = 0;
	for (; OpNo != NumOperands; ++OpNo) {
	Value *Op = C->getOperand(OpNo);
	Mapped = MapValue(Op, VM, Flags, TypeMapper);
	if (Mapped != C) break;
	}

	// See if the type mapper wants to remap the type as well.
	Type *NewTy = C->getType();
	if (TypeMapper)
	NewTy = TypeMapper->remapType(NewTy);

	// If the result type and all operands match up, then just insert an identity
	// mapping.
	if (OpNo == NumOperands && NewTy == C->getType())
	return VM[V] = C;

	// Okay, we need to create a new constant. We've already processed some or
	// all of the operands, set them all up now.
	SmallVector<Constant*, 8> Ops;
	Ops.reserve(NumOperands);
	for (unsigned j = 0; j != OpNo; ++j)
	Ops.push_back(cast<Constant>(C->getOperand(j)));

	// If one of the operands mismatch, push it and the other mapped operands.
	if (OpNo != NumOperands) {
	Ops.push_back(cast<Constant>(Mapped));

	// Map the rest of the operands that aren't processed yet.
	for (++OpNo; OpNo != NumOperands; ++OpNo)
	Ops.push_back(MapValue(cast<Constant>(C->getOperand(OpNo)), VM,
	Flags, TypeMapper));
	}

	if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
	return VM[V] = CE->getWithOperands(Ops, NewTy);
	if (isa<ConstantArray>(C))
	return VM[V] = ConstantArray::get(cast<ArrayType>(NewTy), Ops);
	if (isa<ConstantStruct>(C))
	return VM[V] = ConstantStruct::get(cast<StructType>(NewTy), Ops);
	if (isa<ConstantVector>(C))
	return VM[V] = ConstantVector::get(Ops);
	// If this is a no-operand constant, it must be because the type was remapped.
	if (isa<UndefValue>(C))
	return VM[V] = UndefValue::get(NewTy);
	if (isa<ConstantAggregateZero>(C))
	return VM[V] = ConstantAggregateZero::get(NewTy);
	assert(isa<ConstantPointerNull>(C));
	return VM[V] = ConstantPointerNull::get(cast<PointerType>(NewTy));
	}

	/// RemapInstruction - Convert the instruction operands from referencing the
	/// current values into those specified by VMap.
	///
	void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &VMap,
	RemapFlags Flags, ValueMapTypeRemapper *TypeMapper){
	// Remap operands.
	for (User::op_iterator op = I->op_begin(), E = I->op_end(); op != E; ++op) {
	Value V = MapValue(op, VMap, Flags, TypeMapper);
	// If we aren't ignoring missing entries, assert that something happened.
	if (V != 0)
	*op = V;
	else
	assert((Flags & RF_IgnoreMissingEntries) &&
	"Referenced value not in value map!");
	}

	// Remap phi nodes' incoming blocks.
	if (PHINode *PN = dyn_cast<PHINode>(I)) {
	for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
	Value *V = MapValue(PN->getIncomingBlock(i), VMap, Flags);
	// If we aren't ignoring missing entries, assert that something happened.
	if (V != 0)
	PN->setIncomingBlock(i, cast<BasicBlock>(V));
	else
	assert((Flags & RF_IgnoreMissingEntries) &&
	"Referenced block not in value map!");
	}
	}

	// 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) {
	MDNode *Old = MI->second;
	MDNode *New = MapValue(Old, VMap, Flags, TypeMapper);
	if (New != Old)
	I->setMetadata(MI->first, New);
	}

	// If the instruction's type is being remapped, do so now.
	if (TypeMapper)
	I->mutateType(TypeMapper->remapType(I->getType()));
	}