Пример #1
0
/// See comments in Cloning.h.
BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB,
                                  ValueToValueMapTy &VMap,
                                  const Twine &NameSuffix, Function *F,
                                  ClonedCodeInfo *CodeInfo) {
  BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
  if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);

  bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
  
  // Loop over all instructions, and copy them over.
  for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end();
       II != IE; ++II) {
    Instruction *NewInst = II->clone();
    if (II->hasName())
      NewInst->setName(II->getName()+NameSuffix);
    NewBB->getInstList().push_back(NewInst);
    VMap[&*II] = NewInst; // Add instruction map to value.

    hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
    if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
      if (isa<ConstantInt>(AI->getArraySize()))
        hasStaticAllocas = true;
      else
        hasDynamicAllocas = true;
    }
  }
  
  if (CodeInfo) {
    CodeInfo->ContainsCalls          |= hasCalls;
    CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
    CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas && 
                                        BB != &BB->getParent()->getEntryBlock();
  }
  return NewBB;
}
Пример #2
0
void HeterotbbTransform::copy_function (Function* NF, Function* F) {
    DenseMap<const Value*, Value *> ValueMap;
    // Get the names of the parameters for old function
    for(Function::arg_iterator FI = F->arg_begin(), FE=F->arg_end(), DI=NF->arg_begin(); FE!=FI; ++FI,++DI) {
        DI->setName(FI->getName());
        ValueMap[FI]=DI;
    }

    for (Function::const_iterator BI=F->begin(),BE = F->end(); BI != BE; ++BI) {
        const BasicBlock &FBB = *BI;
        BasicBlock *NFBB = BasicBlock::Create(FBB.getContext(), "", NF);
        ValueMap[&FBB] = NFBB;
        if (FBB.hasName()) {
            NFBB->setName(FBB.getName());
            //DEBUG(dbgs()<<NFBB->getName()<<"\n");
        }
        for (BasicBlock::const_iterator II = FBB.begin(), IE = FBB.end(); II != IE; ++II) {
            Instruction *NFInst = II->clone(/*F->getContext()*/);
            if (II->hasName()) NFInst->setName(II->getName());
            const Instruction *FInst = &(*II);
            rewrite_instruction((Instruction *)FInst, NFInst, ValueMap);
            NFBB->getInstList().push_back(NFInst);
            ValueMap[II] = NFInst;
        }
    }
    // Remap the instructions again to take care of forward jumps
    for (Function::iterator BB = NF->begin(), BE=NF->end(); BB != BE; ++ BB) {
        for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II) {
            int opIdx = 0;
            //DEBUG(dbgs()<<*II<<"\n");
            for (User::op_iterator i = II->op_begin(), e = II->op_end(); i != e; ++i, opIdx++) {
                Value *V = *i;
                if (ValueMap[V] != NULL) {
                    II->setOperand(opIdx, ValueMap[V]);
                }
            }
        }
    }
    //NF->dump();

}
Пример #3
0
/// CloneBlock - The specified block is found to be reachable, clone it and
/// anything that it can reach.
void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
                                       std::vector<const BasicBlock*> &ToClone){
  TrackingVH<Value> &BBEntry = VMap[BB];

  // Have we already cloned this block?
  if (BBEntry) return;
  
  // Nope, clone it now.
  BasicBlock *NewBB;
  BBEntry = NewBB = BasicBlock::Create(BB->getContext());
  if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);

  bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
  
  // Loop over all instructions, and copy them over, DCE'ing as we go.  This
  // loop doesn't include the terminator.
  for (BasicBlock::const_iterator II = BB->begin(), IE = --BB->end();
       II != IE; ++II) {
    // If this instruction constant folds, don't bother cloning the instruction,
    // instead, just add the constant to the value map.
    if (Constant *C = ConstantFoldMappedInstruction(II)) {
      VMap[II] = C;
      continue;
    }

    Instruction *NewInst = II->clone();
    if (II->hasName())
      NewInst->setName(II->getName()+NameSuffix);
    NewBB->getInstList().push_back(NewInst);
    VMap[II] = NewInst;                // Add instruction map to value.
    
    hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
    if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
      if (isa<ConstantInt>(AI->getArraySize()))
        hasStaticAllocas = true;
      else
        hasDynamicAllocas = true;
    }
  }
  
  // Finally, clone over the terminator.
  const TerminatorInst *OldTI = BB->getTerminator();
  bool TerminatorDone = false;
  if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) {
    if (BI->isConditional()) {
      // If the condition was a known constant in the callee...
      ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
      // Or is a known constant in the caller...
      if (Cond == 0) {
        Value *V = VMap[BI->getCondition()];
        Cond = dyn_cast_or_null<ConstantInt>(V);
      }

      // Constant fold to uncond branch!
      if (Cond) {
        BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
        VMap[OldTI] = BranchInst::Create(Dest, NewBB);
        ToClone.push_back(Dest);
        TerminatorDone = true;
      }
    }
  } else if (const SwitchInst *SI = dyn_cast<SwitchInst>(OldTI)) {
    // If switching on a value known constant in the caller.
    ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition());
    if (Cond == 0) { // Or known constant after constant prop in the callee...
      Value *V = VMap[SI->getCondition()];
      Cond = dyn_cast_or_null<ConstantInt>(V);
    }
    if (Cond) {     // Constant fold to uncond branch!
      BasicBlock *Dest = SI->getSuccessor(SI->findCaseValue(Cond));
      VMap[OldTI] = BranchInst::Create(Dest, NewBB);
      ToClone.push_back(Dest);
      TerminatorDone = true;
    }
  }
  
  if (!TerminatorDone) {
    Instruction *NewInst = OldTI->clone();
    if (OldTI->hasName())
      NewInst->setName(OldTI->getName()+NameSuffix);
    NewBB->getInstList().push_back(NewInst);
    VMap[OldTI] = NewInst;             // Add instruction map to value.
    
    // Recursively clone any reachable successor blocks.
    const TerminatorInst *TI = BB->getTerminator();
    for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
      ToClone.push_back(TI->getSuccessor(i));
  }
  
  if (CodeInfo) {
    CodeInfo->ContainsCalls          |= hasCalls;
    CodeInfo->ContainsUnwinds        |= isa<UnwindInst>(OldTI);
    CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
    CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas && 
      BB != &BB->getParent()->front();
  }
  
  if (ReturnInst *RI = dyn_cast<ReturnInst>(NewBB->getTerminator()))
    Returns.push_back(RI);
}
Пример #4
0
/// The specified block is found to be reachable, clone it and
/// anything that it can reach.
void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
                                       BasicBlock::const_iterator StartingInst,
                                       std::vector<const BasicBlock*> &ToClone){
  WeakVH &BBEntry = VMap[BB];

  // Have we already cloned this block?
  if (BBEntry) return;
  
  // Nope, clone it now.
  BasicBlock *NewBB;
  BBEntry = NewBB = BasicBlock::Create(BB->getContext());
  if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);

  // It is only legal to clone a function if a block address within that
  // function is never referenced outside of the function.  Given that, we
  // want to map block addresses from the old function to block addresses in
  // the clone. (This is different from the generic ValueMapper
  // implementation, which generates an invalid blockaddress when
  // cloning a function.)
  //
  // Note that we don't need to fix the mapping for unreachable blocks;
  // the default mapping there is safe.
  if (BB->hasAddressTaken()) {
    Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
                                            const_cast<BasicBlock*>(BB));
    VMap[OldBBAddr] = BlockAddress::get(NewFunc, NewBB);
  }

  bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;

  // Loop over all instructions, and copy them over, DCE'ing as we go.  This
  // loop doesn't include the terminator.
  for (BasicBlock::const_iterator II = StartingInst, IE = --BB->end();
       II != IE; ++II) {

    Instruction *NewInst = II->clone();

    // Eagerly remap operands to the newly cloned instruction, except for PHI
    // nodes for which we defer processing until we update the CFG.
    if (!isa<PHINode>(NewInst)) {
      RemapInstruction(NewInst, VMap,
                       ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);

      // If we can simplify this instruction to some other value, simply add
      // a mapping to that value rather than inserting a new instruction into
      // the basic block.
      if (Value *V =
              SimplifyInstruction(NewInst, BB->getModule()->getDataLayout())) {
        // On the off-chance that this simplifies to an instruction in the old
        // function, map it back into the new function.
        if (Value *MappedV = VMap.lookup(V))
          V = MappedV;

        VMap[&*II] = V;
        delete NewInst;
        continue;
      }
    }

    if (II->hasName())
      NewInst->setName(II->getName()+NameSuffix);
    VMap[&*II] = NewInst; // Add instruction map to value.
    NewBB->getInstList().push_back(NewInst);
    hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));

    if (CodeInfo)
      if (auto CS = ImmutableCallSite(&*II))
        if (CS.hasOperandBundles())
          CodeInfo->OperandBundleCallSites.push_back(NewInst);

    if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
      if (isa<ConstantInt>(AI->getArraySize()))
        hasStaticAllocas = true;
      else
        hasDynamicAllocas = true;
    }
  }
  
  // Finally, clone over the terminator.
  const TerminatorInst *OldTI = BB->getTerminator();
  bool TerminatorDone = false;
  if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) {
    if (BI->isConditional()) {
      // If the condition was a known constant in the callee...
      ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
      // Or is a known constant in the caller...
      if (!Cond) {
        Value *V = VMap[BI->getCondition()];
        Cond = dyn_cast_or_null<ConstantInt>(V);
      }

      // Constant fold to uncond branch!
      if (Cond) {
        BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
        VMap[OldTI] = BranchInst::Create(Dest, NewBB);
        ToClone.push_back(Dest);
        TerminatorDone = true;
      }
    }
  } else if (const SwitchInst *SI = dyn_cast<SwitchInst>(OldTI)) {
    // If switching on a value known constant in the caller.
    ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition());
    if (!Cond) { // Or known constant after constant prop in the callee...
      Value *V = VMap[SI->getCondition()];
      Cond = dyn_cast_or_null<ConstantInt>(V);
    }
    if (Cond) {     // Constant fold to uncond branch!
      SwitchInst::ConstCaseIt Case = SI->findCaseValue(Cond);
      BasicBlock *Dest = const_cast<BasicBlock*>(Case.getCaseSuccessor());
      VMap[OldTI] = BranchInst::Create(Dest, NewBB);
      ToClone.push_back(Dest);
      TerminatorDone = true;
    }
  }
  
  if (!TerminatorDone) {
    Instruction *NewInst = OldTI->clone();
    if (OldTI->hasName())
      NewInst->setName(OldTI->getName()+NameSuffix);
    NewBB->getInstList().push_back(NewInst);
    VMap[OldTI] = NewInst;             // Add instruction map to value.

    if (CodeInfo)
      if (auto CS = ImmutableCallSite(OldTI))
        if (CS.hasOperandBundles())
          CodeInfo->OperandBundleCallSites.push_back(NewInst);

    // Recursively clone any reachable successor blocks.
    const TerminatorInst *TI = BB->getTerminator();
    for (const BasicBlock *Succ : TI->successors())
      ToClone.push_back(Succ);
  }
  
  if (CodeInfo) {
    CodeInfo->ContainsCalls          |= hasCalls;
    CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
    CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas && 
      BB != &BB->getParent()->front();
  }
}
Пример #5
0
void HeterotbbTransform::gen_opt_code_per_f (Function* NF, Function* F) {
    // Get the names of the parameters for old function
    Function::arg_iterator FI = F->arg_begin();
    Argument *classname = &*FI;
    FI++;
    Argument *numiters = &*FI;

    // Set the names of the parameters for new function
    Function::arg_iterator DestI = NF->arg_begin();
    DestI->setName(classname->getName());
    Argument *class_name = &(*DestI);
    //second argument
    DestI++;
    DestI->setName(numiters->getName());
    Argument *num_iters = &(*DestI);

#ifdef EXPLICIT_REWRITE
    DenseMap<const Value*, Value *> ValueMap;
#else
    ValueToValueMapTy ValueMap;
#endif

#if EXPLICIT_REWRITE
    //get the old basic block and create a new one
    Function::const_iterator BI = F->begin();
    const BasicBlock &FB = *BI;
    BasicBlock *NFBB = BasicBlock::Create(FB.getContext(), "", NF);
    if (FB.hasName()) {
        NFBB->setName(FB.getName());
        //DEBUG(dbgs()<<FB.getName()<<"\n");
    }
    ValueMap[&FB] = NFBB;

    ValueMap[numiters] = num_iters;
    //must create a new instruction which casts i32* back to the class name
    CastInst *StrucRevCast = CastInst::Create(Instruction::BitCast, class_name,
                             classname->getType(), classname->getName(), NFBB);
    ValueMap[classname] = StrucRevCast;


    for (BasicBlock::const_iterator II = FB.begin(), IE = FB.end(); II != IE; ++II) {
        Instruction *NFInst = II->clone(/*F->getContext()*/);
        //	DEBUG(dbgs()<<*II<<"\n");
        if (II->hasName()) NFInst->setName(II->getName());
        const Instruction *FInst = &(*II);
        rewrite_instruction((Instruction *)FInst, NFInst, ValueMap);
        NFBB->getInstList().push_back(NFInst);
        ValueMap[II] = NFInst;
    }
    BI++;

    for (Function::const_iterator /*BI=F->begin(),*/BE = F->end(); BI != BE; ++BI) {
        const BasicBlock &FBB = *BI;
        BasicBlock *NFBB = BasicBlock::Create(FBB.getContext(), "", NF);
        ValueMap[&FBB] = NFBB;
        if (FBB.hasName()) {
            NFBB->setName(FBB.getName());
            //DEBUG(dbgs()<<NFBB->getName()<<"\n");
        }
        for (BasicBlock::const_iterator II = FBB.begin(), IE = FBB.end(); II != IE; ++II) {
            Instruction *NFInst = II->clone(/*F->getContext()*/);
            if (II->hasName()) NFInst->setName(II->getName());
            const Instruction *FInst = &(*II);
            rewrite_instruction((Instruction *)FInst, NFInst, ValueMap);
            NFBB->getInstList().push_back(NFInst);
            ValueMap[II] = NFInst;
        }
    }
    // Remap the instructions again to take care of forward jumps
    for (Function::iterator BB = NF->begin(), BE=NF->end(); BB != BE; ++ BB) {
        for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II) {
            int opIdx = 0;
            //DEBUG(dbgs()<<*II<<"\n");
            for (User::op_iterator i = II->op_begin(), e = II->op_end(); i != e; ++i, opIdx++) {
                Value *V = *i;
                if (ValueMap[V] != NULL) {
                    II->setOperand(opIdx, ValueMap[V]);
                }
            }
        }
    }
#else
    Function::const_iterator BI = F->begin();
    const BasicBlock &FB = *BI;
    BasicBlock *NFBB = BasicBlock::Create(FB.getContext(), "", NF);
    if (FB.hasName()) {
        NFBB->setName(FB.getName());
    }
    ValueMap[&FB] = NFBB;
    CastInst *StrucRevCast = CastInst::Create(Instruction::BitCast, class_name,
                             classname->getType(), classname->getName(), NFBB);
    ValueMap[classname] = StrucRevCast;
    ValueMap[numiters] = num_iters;
    CloneFunctionWithExistingBBInto(NF, NFBB, F, ValueMap, "");
#endif
}
Пример #6
0
/**
 * Generate code for
 */
void HeteroOMPTransform::gen_code_per_f (Function* NF, Function* F, Instruction *max_threads){
	
	Function::arg_iterator FI = F->arg_begin();
	Argument *ctxname = &*FI;

	Function::arg_iterator DestI = NF->arg_begin();
	DestI->setName(ctxname->getName()); 
	Argument *ctx_name = &(*DestI);
	DestI++;
	DestI->setName("tid");
	Argument *num_iters = &(*DestI);

#ifdef EXPLICIT_REWRITE
	DenseMap<const Value*, Value *> ValueMap;
#else
	ValueToValueMapTy ValueMap;
#endif

	//get the old basic block and create a new one
	Function::const_iterator BI = F->begin();
	const BasicBlock &FB = *BI;
	BasicBlock *NFBB = BasicBlock::Create(FB.getContext(), "", NF);
	if (FB.hasName()){
		NFBB->setName(FB.getName());
	}
	ValueMap[&FB] = NFBB;

	//ValueMap[numiters] = num_iters;
	ValueMap[ctxname] = ctx_name;

#if EXPLICIT_REWRITE
	for (BasicBlock::const_iterator II = FB.begin(), IE = FB.end(); II != IE; ++II) {
		Instruction *NFInst = II->clone(/*F->getContext()*/);
		//	DEBUG(dbgs()<<*II<<"\n");
		if (II->hasName()) NFInst->setName(II->getName());
		const Instruction *FInst = &(*II);
		rewrite_instruction((Instruction *)FInst, NFInst, ValueMap);
		NFBB->getInstList().push_back(NFInst);
		ValueMap[II] = NFInst;
	}
	BI++;

	for (Function::const_iterator /*BI=F->begin(),*/BE = F->end();BI != BE; ++BI) {
		const BasicBlock &FBB = *BI;
		BasicBlock *NFBB = BasicBlock::Create(FBB.getContext(), "", NF);
		ValueMap[&FBB] = NFBB;
		if (FBB.hasName()){
			NFBB->setName(FBB.getName());
			//DEBUG(dbgs()<<NFBB->getName()<<"\n");
		}
		for (BasicBlock::const_iterator II = FBB.begin(), IE = FBB.end(); II != IE; ++II) {
			Instruction *NFInst = II->clone(/*F->getContext()*/);
			if (II->hasName()) NFInst->setName(II->getName());
			const Instruction *FInst = &(*II);
			rewrite_instruction((Instruction *)FInst, NFInst, ValueMap);
			NFBB->getInstList().push_back(NFInst);
			ValueMap[II] = NFInst;
		}
	}
	// Remap the instructions again to take care of forward jumps
	for (Function::iterator BB = NF->begin(), BE=NF->end(); BB != BE; ++ BB) {
		for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II){
			int opIdx = 0;
			//DEBUG(dbgs()<<*II<<"\n");
			for (User::op_iterator i = II->op_begin(), e = II->op_end(); i != e; ++i, opIdx++) {
				Value *V = *i;
				if (ValueMap[V] != NULL) {
					II->setOperand(opIdx, ValueMap[V]);
				}
			}
		}
	}
#else
	SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
	CloneFunctionInto(NF, F, ValueMap, false, Returns, "");
#endif

	//max_threads->dump();
	/* Remap openmp omp_num_threads() and omp_thread_num() */ 
	/*
	 * define internal void @_Z20initialize_variablesiPfS_.omp_fn.4(i8* nocapture %.omp_data_i) nounwind ssp {
     * entry:
     * %0 = bitcast i8* %.omp_data_i to i32*           ; <i32*> [#uses=1]
     * %1 = load i32* %0, align 8                      ; <i32> [#uses=2]
     * %2 = tail call i32 @omp_get_num_threads() nounwind readnone ; <i32> [#uses=2]
     * %3 = tail call i32 @omp_get_thread_num() nounwind readnone ; <i32> [#uses=2]
	   %4 = sdiv i32 %1, %2
	   %5 = mul nsw i32 %4, %2
       %6 = icmp ne i32 %5, %1
       %7 = zext i1 %6 to i32
	 */
	vector<Instruction *> toDelete;
	for (Function::iterator BB = NF->begin(), BE=NF->end(); BB != BE; ++ BB) {
		for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II){
			if (isa<CallInst>(II)) {
				CallSite CI(cast<Instruction>(II));
				if (CI.getCalledFunction() != NULL){ 
					string called_func_name = CI.getCalledFunction()->getName();
					if (called_func_name == OMP_GET_NUM_THREADS_NAME && CI.arg_size() == 0) {
						II->replaceAllUsesWith(ValueMap[max_threads]);
						toDelete.push_back(II);
					}
					else if (called_func_name == OMP_GET_THREAD_NUM_NAME && CI.arg_size() == 0) {
						II->replaceAllUsesWith(num_iters);
						toDelete.push_back(II);
					}
				}
			}
		}
	}


	/* Delete the last branch instruction of the first basic block -- Assuming it is safe */
	Function::iterator nfBB = NF->begin();
	TerminatorInst *lastI = nfBB->getTerminator();
	BranchInst *bI;
	BasicBlock *returnBlock;
	if ((bI = dyn_cast<BranchInst>(lastI)) && bI->isConditional() && 
		(returnBlock = bI->getSuccessor(1)) && 
		(returnBlock->getName() == "return")) {
		/* modify to a unconditional branch to next basic block and not return */
		Instruction *bbI = BranchInst::Create(bI->getSuccessor(0),lastI);
		bbI->dump();
		toDelete.push_back(lastI);
	}

	//NF->dump();
	while(!toDelete.empty()) {
		Instruction *g = toDelete.back();
		//g->replaceAllUsesWith(UndefValue::get(g->getType()));
		toDelete.pop_back();
		g->eraseFromParent();
	}

	//NF->dump();
}
Пример #7
0
void WorklessInstrument::CloneInnerLoop(Loop * pLoop, vector<BasicBlock *> & vecAdd, ValueToValueMapTy & VMap, set<BasicBlock *> & setCloned)
{
	Function * pFunction = pLoop->getHeader()->getParent();
	BasicBlock * pPreHeader = vecAdd[0];

	SmallVector<BasicBlock *, 4> ExitBlocks;
	pLoop->getExitBlocks(ExitBlocks);

	set<BasicBlock *> setExitBlocks;

	for(unsigned long i = 0; i < ExitBlocks.size(); i++)
	{
		setExitBlocks.insert(ExitBlocks[i]);
	}

	for(unsigned long i = 0; i < ExitBlocks.size(); i++ )
	{
		VMap[ExitBlocks[i]] = ExitBlocks[i];
	}

	vector<BasicBlock *> ToClone;
	vector<BasicBlock *> BeenCloned;

	
	//clone loop
	ToClone.push_back(pLoop->getHeader());

	while(ToClone.size()>0)
	{
		BasicBlock * pCurrent = ToClone.back();
		ToClone.pop_back();

		WeakVH & BBEntry = VMap[pCurrent];
		if (BBEntry)
		{
			continue;
		}

		BasicBlock * NewBB;
		BBEntry = NewBB = BasicBlock::Create(pCurrent->getContext(), "", pFunction);

		if(pCurrent->hasName())
		{
			NewBB->setName(pCurrent->getName() + ".CPI");
		}

		if(pCurrent->hasAddressTaken())
		{
			errs() << "hasAddressTaken branch\n" ;
			exit(0);
		}

		for(BasicBlock::const_iterator II = pCurrent->begin(); II != pCurrent->end(); ++II )
		{
			Instruction * NewInst = II->clone();
			if(II->hasName())
			{
				NewInst->setName(II->getName() + ".CPI");
			}
			VMap[II] = NewInst;
			NewBB->getInstList().push_back(NewInst);
		}

		const TerminatorInst *TI = pCurrent->getTerminator();
		for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
		{
			ToClone.push_back(TI->getSuccessor(i));
		}

		setCloned.insert(NewBB);
		BeenCloned.push_back(NewBB);
	}

	//remap value used inside loop
	vector<BasicBlock *>::iterator itVecBegin = BeenCloned.begin();
	vector<BasicBlock *>::iterator itVecEnd = BeenCloned.end();

	for(; itVecBegin != itVecEnd; itVecBegin ++)
	{
		for(BasicBlock::iterator II = (*itVecBegin)->begin(); II != (*itVecBegin)->end(); II ++ )
		{
			//II->dump();
			RemapInstruction(II, VMap);
		}
	}

	//add to the else if body
	BasicBlock * pElseBody = vecAdd[1];

	BasicBlock * pClonedHeader = cast<BasicBlock>(VMap[pLoop->getHeader()]);

	BranchInst::Create(pClonedHeader, pElseBody);

	//errs() << pPreHeader->getName() << "\n";
	for(BasicBlock::iterator II = pClonedHeader->begin(); II != pClonedHeader->end(); II ++ )
	{
		if(PHINode * pPHI = dyn_cast<PHINode>(II))
		{
			vector<int> vecToRemoved;
			for (unsigned i = 0, e = pPHI->getNumIncomingValues(); i != e; ++i) 
			{
				if(pPHI->getIncomingBlock(i) == pPreHeader)
				{
					pPHI->setIncomingBlock(i, pElseBody);
				}
			}
		}
	}

	set<BasicBlock *> setProcessedBlock;

	for(unsigned long i = 0; i < ExitBlocks.size(); i++ )
	{
		if(setProcessedBlock.find(ExitBlocks[i]) != setProcessedBlock.end() )
		{
			continue;
		}
		else
		{
			setProcessedBlock.insert(ExitBlocks[i]);
		}

		for(BasicBlock::iterator II = ExitBlocks[i]->begin(); II != ExitBlocks[i]->end(); II ++ )
		{
			if(PHINode * pPHI = dyn_cast<PHINode>(II))
			{
				unsigned numIncomming = pPHI->getNumIncomingValues();
				for(unsigned i = 0; i<numIncomming; i++)
				{
					BasicBlock * incommingBlock = pPHI->getIncomingBlock(i);
					if(VMap.find(incommingBlock) != VMap.end() )
					{
						Value * incommingValue = pPHI->getIncomingValue(i);

						if(VMap.find(incommingValue) != VMap.end() )
						{
							incommingValue = VMap[incommingValue];
						}

						pPHI->addIncoming(incommingValue, cast<BasicBlock>(VMap[incommingBlock]));

					}
				} 

			}
		}
	}
}
/// DebugACrash - Given a predicate that determines whether a component crashes
/// on a program, try to destructively reduce the program while still keeping
/// the predicate true.
static bool DebugACrash(BugDriver &BD,  bool (*TestFn)(BugDriver &, Module *)) {
  // See if we can get away with nuking some of the global variable initializers
  // in the program...
  if (BD.getProgram()->global_begin() != BD.getProgram()->global_end()) {
    // Now try to reduce the number of global variable initializers in the
    // module to something small.
    Module *M = CloneModule(BD.getProgram());
    bool DeletedInit = false;

    for (Module::global_iterator I = M->global_begin(), E = M->global_end();
         I != E; ++I)
      if (I->hasInitializer()) {
        I->setInitializer(0);
        I->setLinkage(GlobalValue::ExternalLinkage);
        DeletedInit = true;
      }

    if (!DeletedInit) {
      delete M;  // No change made...
    } else {
      // See if the program still causes a crash...
      std::cout << "\nChecking to see if we can delete global inits: ";

      if (TestFn(BD, M)) {      // Still crashes?
        BD.setNewProgram(M);
        std::cout << "\n*** Able to remove all global initializers!\n";
      } else {                  // No longer crashes?
        std::cout << "  - Removing all global inits hides problem!\n";
        delete M;

        std::vector<GlobalVariable*> GVs;

        for (Module::global_iterator I = BD.getProgram()->global_begin(),
               E = BD.getProgram()->global_end(); I != E; ++I)
          if (I->hasInitializer())
            GVs.push_back(I);

        if (GVs.size() > 1 && !BugpointIsInterrupted) {
          std::cout << "\n*** Attempting to reduce the number of global "
                    << "variables in the testcase\n";

          unsigned OldSize = GVs.size();
          ReduceCrashingGlobalVariables(BD, TestFn).reduceList(GVs);

          if (GVs.size() < OldSize)
            BD.EmitProgressBytecode("reduced-global-variables");
        }
      }
    }
  }

  // Now try to reduce the number of functions in the module to something small.
  std::vector<Function*> Functions;
  for (Module::iterator I = BD.getProgram()->begin(),
         E = BD.getProgram()->end(); I != E; ++I)
    if (!I->isDeclaration())
      Functions.push_back(I);

  if (Functions.size() > 1 && !BugpointIsInterrupted) {
    std::cout << "\n*** Attempting to reduce the number of functions "
      "in the testcase\n";

    unsigned OldSize = Functions.size();
    ReduceCrashingFunctions(BD, TestFn).reduceList(Functions);

    if (Functions.size() < OldSize)
      BD.EmitProgressBytecode("reduced-function");
  }

  // Attempt to delete entire basic blocks at a time to speed up
  // convergence... this actually works by setting the terminator of the blocks
  // to a return instruction then running simplifycfg, which can potentially
  // shrinks the code dramatically quickly
  //
  if (!DisableSimplifyCFG && !BugpointIsInterrupted) {
    std::vector<const BasicBlock*> Blocks;
    for (Module::const_iterator I = BD.getProgram()->begin(),
           E = BD.getProgram()->end(); I != E; ++I)
      for (Function::const_iterator FI = I->begin(), E = I->end(); FI !=E; ++FI)
        Blocks.push_back(FI);
    ReduceCrashingBlocks(BD, TestFn).reduceList(Blocks);
  }

  // FIXME: This should use the list reducer to converge faster by deleting
  // larger chunks of instructions at a time!
  unsigned Simplification = 2;
  do {
    if (BugpointIsInterrupted) break;
    --Simplification;
    std::cout << "\n*** Attempting to reduce testcase by deleting instruc"
              << "tions: Simplification Level #" << Simplification << '\n';

    // Now that we have deleted the functions that are unnecessary for the
    // program, try to remove instructions that are not necessary to cause the
    // crash.  To do this, we loop through all of the instructions in the
    // remaining functions, deleting them (replacing any values produced with
    // nulls), and then running ADCE and SimplifyCFG.  If the transformed input
    // still triggers failure, keep deleting until we cannot trigger failure
    // anymore.
    //
    unsigned InstructionsToSkipBeforeDeleting = 0;
  TryAgain:

    // Loop over all of the (non-terminator) instructions remaining in the
    // function, attempting to delete them.
    unsigned CurInstructionNum = 0;
    for (Module::const_iterator FI = BD.getProgram()->begin(),
           E = BD.getProgram()->end(); FI != E; ++FI)
      if (!FI->isDeclaration())
        for (Function::const_iterator BI = FI->begin(), E = FI->end(); BI != E;
             ++BI)
          for (BasicBlock::const_iterator I = BI->begin(), E = --BI->end();
               I != E; ++I, ++CurInstructionNum)
            if (InstructionsToSkipBeforeDeleting) {
              --InstructionsToSkipBeforeDeleting;
            } else {
              if (BugpointIsInterrupted) goto ExitLoops;

              std::cout << "Checking instruction '" << I->getName() << "': ";
              Module *M = BD.deleteInstructionFromProgram(I, Simplification);

              // Find out if the pass still crashes on this pass...
              if (TestFn(BD, M)) {
                // Yup, it does, we delete the old module, and continue trying
                // to reduce the testcase...
                BD.setNewProgram(M);
                InstructionsToSkipBeforeDeleting = CurInstructionNum;
                goto TryAgain;  // I wish I had a multi-level break here!
              }

              // This pass didn't crash without this instruction, try the next
              // one.
              delete M;
            }

    if (InstructionsToSkipBeforeDeleting) {
      InstructionsToSkipBeforeDeleting = 0;
      goto TryAgain;
    }

  } while (Simplification);
ExitLoops:

  // Try to clean up the testcase by running funcresolve and globaldce...
  if (!BugpointIsInterrupted) {
    std::cout << "\n*** Attempting to perform final cleanups: ";
    Module *M = CloneModule(BD.getProgram());
    M = BD.performFinalCleanups(M, true);

    // Find out if the pass still crashes on the cleaned up program...
    if (TestFn(BD, M)) {
      BD.setNewProgram(M);     // Yup, it does, keep the reduced version...
    } else {
      delete M;
    }
  }

  BD.EmitProgressBytecode("reduced-simplified");

  return false;
}
Пример #9
0
/// CloneBlock - The specified block is found to be reachable, clone it and
/// anything that it can reach.
void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
                                       std::vector<const BasicBlock*> &ToClone) {
    TrackingVH<Value> &BBEntry = VMap[BB];

    // Have we already cloned this block?
    if (BBEntry) return;

    // Nope, clone it now.
    BasicBlock *NewBB;
    BBEntry = NewBB = BasicBlock::Create(BB->getContext());
    if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);

    // It is only legal to clone a function if a block address within that
    // function is never referenced outside of the function.  Given that, we
    // want to map block addresses from the old function to block addresses in
    // the clone. (This is different from the generic ValueMapper
    // implementation, which generates an invalid blockaddress when
    // cloning a function.)
    //
    // Note that we don't need to fix the mapping for unreachable blocks;
    // the default mapping there is safe.
    if (BB->hasAddressTaken()) {
        Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
                                                const_cast<BasicBlock*>(BB));
        VMap[OldBBAddr] = BlockAddress::get(NewFunc, NewBB);
    }


    bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;

    // Loop over all instructions, and copy them over, DCE'ing as we go.  This
    // loop doesn't include the terminator.
    for (BasicBlock::const_iterator II = BB->begin(), IE = --BB->end();
            II != IE; ++II) {
        // If this instruction constant folds, don't bother cloning the instruction,
        // instead, just add the constant to the value map.
        if (Constant *C = ConstantFoldMappedInstruction(II)) {
            VMap[II] = C;
            continue;
        }

        Instruction *NewInst = II->clone();
        if (II->hasName())
            NewInst->setName(II->getName()+NameSuffix);
        NewBB->getInstList().push_back(NewInst);
        VMap[II] = NewInst;                // Add instruction map to value.

        hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
        if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
            if (isa<ConstantInt>(AI->getArraySize()))
                hasStaticAllocas = true;
            else
                hasDynamicAllocas = true;
        }
    }

    // Finally, clone over the terminator.
    const TerminatorInst *OldTI = BB->getTerminator();
    bool TerminatorDone = false;
    if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) {
        if (BI->isConditional()) {
            // If the condition was a known constant in the callee...
            ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
            // Or is a known constant in the caller...
            if (Cond == 0) {
                Value *V = VMap[BI->getCondition()];
                Cond = dyn_cast_or_null<ConstantInt>(V);
            }

            // Constant fold to uncond branch!
            if (Cond) {
                BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
                VMap[OldTI] = BranchInst::Create(Dest, NewBB);
                ToClone.push_back(Dest);
                TerminatorDone = true;
            }
        }
    } else if (const SwitchInst *SI = dyn_cast<SwitchInst>(OldTI)) {
        // If switching on a value known constant in the caller.
        ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition());
        if (Cond == 0) { // Or known constant after constant prop in the callee...
            Value *V = VMap[SI->getCondition()];
            Cond = dyn_cast_or_null<ConstantInt>(V);
        }
        if (Cond) {     // Constant fold to uncond branch!
            SwitchInst::ConstCaseIt Case = SI->findCaseValue(Cond);
            BasicBlock *Dest = const_cast<BasicBlock*>(Case.getCaseSuccessor());
            VMap[OldTI] = BranchInst::Create(Dest, NewBB);
            ToClone.push_back(Dest);
            TerminatorDone = true;
        }
    }

    if (!TerminatorDone) {
        Instruction *NewInst = OldTI->clone();
        if (OldTI->hasName())
            NewInst->setName(OldTI->getName()+NameSuffix);
        NewBB->getInstList().push_back(NewInst);
        VMap[OldTI] = NewInst;             // Add instruction map to value.

        // Recursively clone any reachable successor blocks.
        const TerminatorInst *TI = BB->getTerminator();
        for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
            ToClone.push_back(TI->getSuccessor(i));
    }

    if (CodeInfo) {
        CodeInfo->ContainsCalls          |= hasCalls;
        CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
        CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
                                            BB != &BB->getParent()->front();
    }

    if (ReturnInst *RI = dyn_cast<ReturnInst>(NewBB->getTerminator()))
        Returns.push_back(RI);
}