| //===-- ValueEnumerator.cpp - Number values and types for bitcode writer --===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the ValueEnumerator class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ValueEnumerator.h" |
| #include "llvm/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/Metadata.h" |
| #include "llvm/Module.h" |
| #include "llvm/TypeSymbolTable.h" |
| #include "llvm/ValueSymbolTable.h" |
| #include "llvm/Instructions.h" |
| #include <algorithm> |
| using namespace llvm; |
| |
| static bool isSingleValueType(const std::pair<const llvm::Type*, |
| unsigned int> &P) { |
| return P.first->isSingleValueType(); |
| } |
| |
| static bool isIntegerValue(const std::pair<const Value*, unsigned> &V) { |
| return isa<IntegerType>(V.first->getType()); |
| } |
| |
| static bool CompareByFrequency(const std::pair<const llvm::Type*, |
| unsigned int> &P1, |
| const std::pair<const llvm::Type*, |
| unsigned int> &P2) { |
| return P1.second > P2.second; |
| } |
| |
| /// ValueEnumerator - Enumerate module-level information. |
| ValueEnumerator::ValueEnumerator(const Module *M) { |
| // Enumerate the global variables. |
| for (Module::const_global_iterator I = M->global_begin(), |
| E = M->global_end(); I != E; ++I) |
| EnumerateValue(I); |
| |
| // Enumerate the functions. |
| for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) { |
| EnumerateValue(I); |
| EnumerateAttributes(cast<Function>(I)->getAttributes()); |
| } |
| |
| // Enumerate the aliases. |
| for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end(); |
| I != E; ++I) |
| EnumerateValue(I); |
| |
| // Remember what is the cutoff between globalvalue's and other constants. |
| unsigned FirstConstant = Values.size(); |
| |
| // Enumerate the global variable initializers. |
| for (Module::const_global_iterator I = M->global_begin(), |
| E = M->global_end(); I != E; ++I) |
| if (I->hasInitializer()) |
| EnumerateValue(I->getInitializer()); |
| |
| // Enumerate the aliasees. |
| for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end(); |
| I != E; ++I) |
| EnumerateValue(I->getAliasee()); |
| |
| // Enumerate types used by the type symbol table. |
| EnumerateTypeSymbolTable(M->getTypeSymbolTable()); |
| |
| // Insert constants that are named at module level into the slot pool so that |
| // the module symbol table can refer to them... |
| EnumerateValueSymbolTable(M->getValueSymbolTable()); |
| |
| // Enumerate types used by function bodies and argument lists. |
| for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) { |
| |
| for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end(); |
| I != E; ++I) |
| EnumerateType(I->getType()); |
| |
| for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) |
| for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E;++I){ |
| for (User::const_op_iterator OI = I->op_begin(), E = I->op_end(); |
| OI != E; ++OI) |
| EnumerateOperandType(*OI); |
| EnumerateType(I->getType()); |
| if (const CallInst *CI = dyn_cast<CallInst>(I)) |
| EnumerateAttributes(CI->getAttributes()); |
| else if (const InvokeInst *II = dyn_cast<InvokeInst>(I)) |
| EnumerateAttributes(II->getAttributes()); |
| } |
| } |
| |
| // Optimize constant ordering. |
| OptimizeConstants(FirstConstant, Values.size()); |
| |
| // Sort the type table by frequency so that most commonly used types are early |
| // in the table (have low bit-width). |
| std::stable_sort(Types.begin(), Types.end(), CompareByFrequency); |
| |
| // Partition the Type ID's so that the single-value types occur before the |
| // aggregate types. This allows the aggregate types to be dropped from the |
| // type table after parsing the global variable initializers. |
| std::partition(Types.begin(), Types.end(), isSingleValueType); |
| |
| // Now that we rearranged the type table, rebuild TypeMap. |
| for (unsigned i = 0, e = Types.size(); i != e; ++i) |
| TypeMap[Types[i].first] = i+1; |
| } |
| |
| // Optimize constant ordering. |
| namespace { |
| struct CstSortPredicate { |
| ValueEnumerator &VE; |
| explicit CstSortPredicate(ValueEnumerator &ve) : VE(ve) {} |
| bool operator()(const std::pair<const Value*, unsigned> &LHS, |
| const std::pair<const Value*, unsigned> &RHS) { |
| // Sort by plane. |
| if (LHS.first->getType() != RHS.first->getType()) |
| return VE.getTypeID(LHS.first->getType()) < |
| VE.getTypeID(RHS.first->getType()); |
| // Then by frequency. |
| return LHS.second > RHS.second; |
| } |
| }; |
| } |
| |
| /// OptimizeConstants - Reorder constant pool for denser encoding. |
| void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) { |
| if (CstStart == CstEnd || CstStart+1 == CstEnd) return; |
| |
| CstSortPredicate P(*this); |
| std::stable_sort(Values.begin()+CstStart, Values.begin()+CstEnd, P); |
| |
| // Ensure that integer constants are at the start of the constant pool. This |
| // is important so that GEP structure indices come before gep constant exprs. |
| std::partition(Values.begin()+CstStart, Values.begin()+CstEnd, |
| isIntegerValue); |
| |
| // Rebuild the modified portion of ValueMap. |
| for (; CstStart != CstEnd; ++CstStart) |
| ValueMap[Values[CstStart].first] = CstStart+1; |
| } |
| |
| |
| /// EnumerateTypeSymbolTable - Insert all of the types in the specified symbol |
| /// table. |
| void ValueEnumerator::EnumerateTypeSymbolTable(const TypeSymbolTable &TST) { |
| for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); |
| TI != TE; ++TI) |
| EnumerateType(TI->second); |
| } |
| |
| /// EnumerateValueSymbolTable - Insert all of the values in the specified symbol |
| /// table into the values table. |
| void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) { |
| for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end(); |
| VI != VE; ++VI) |
| EnumerateValue(VI->getValue()); |
| } |
| |
| void ValueEnumerator::EnumerateValue(const Value *V) { |
| assert(V->getType() != Type::VoidTy && "Can't insert void values!"); |
| |
| // Check to see if it's already in! |
| unsigned &ValueID = ValueMap[V]; |
| if (ValueID) { |
| // Increment use count. |
| Values[ValueID-1].second++; |
| return; |
| } |
| |
| // Enumerate the type of this value. |
| EnumerateType(V->getType()); |
| |
| if (const Constant *C = dyn_cast<Constant>(V)) { |
| if (isa<GlobalValue>(C)) { |
| // Initializers for globals are handled explicitly elsewhere. |
| } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) { |
| // Do not enumerate the initializers for an array of simple characters. |
| // The initializers just polute the value table, and we emit the strings |
| // specially. |
| } else if (C->getNumOperands()) { |
| // If a constant has operands, enumerate them. This makes sure that if a |
| // constant has uses (for example an array of const ints), that they are |
| // inserted also. |
| |
| // We prefer to enumerate them with values before we enumerate the user |
| // itself. This makes it more likely that we can avoid forward references |
| // in the reader. We know that there can be no cycles in the constants |
| // graph that don't go through a global variable. |
| for (User::const_op_iterator I = C->op_begin(), E = C->op_end(); |
| I != E; ++I) |
| EnumerateValue(*I); |
| |
| // Finally, add the value. Doing this could make the ValueID reference be |
| // dangling, don't reuse it. |
| Values.push_back(std::make_pair(V, 1U)); |
| ValueMap[V] = Values.size(); |
| return; |
| } |
| } |
| |
| if (const MDNode *N = dyn_cast<MDNode>(V)) { |
| Values.push_back(std::make_pair(V, 1U)); |
| ValueMap[V] = Values.size(); |
| ValueID = Values.size(); |
| for (MDNode::const_elem_iterator I = N->elem_begin(), E = N->elem_end(); |
| I != E; ++I) { |
| if (*I) |
| EnumerateValue(*I); |
| else |
| EnumerateType(Type::VoidTy); |
| } |
| return; |
| } |
| |
| if (const NamedMDNode *N = dyn_cast<NamedMDNode>(V)) { |
| for(NamedMDNode::const_elem_iterator I = N->elem_begin(), |
| E = N->elem_end(); I != E; ++I) { |
| MetadataBase *M = *I; |
| EnumerateValue(M); |
| } |
| Values.push_back(std::make_pair(V, 1U)); |
| ValueMap[V] = Values.size(); |
| return; |
| } |
| |
| // Add the value. |
| Values.push_back(std::make_pair(V, 1U)); |
| ValueID = Values.size(); |
| } |
| |
| |
| void ValueEnumerator::EnumerateType(const Type *Ty) { |
| unsigned &TypeID = TypeMap[Ty]; |
| |
| if (TypeID) { |
| // If we've already seen this type, just increase its occurrence count. |
| Types[TypeID-1].second++; |
| return; |
| } |
| |
| // First time we saw this type, add it. |
| Types.push_back(std::make_pair(Ty, 1U)); |
| TypeID = Types.size(); |
| |
| // Enumerate subtypes. |
| for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end(); |
| I != E; ++I) |
| EnumerateType(*I); |
| } |
| |
| // Enumerate the types for the specified value. If the value is a constant, |
| // walk through it, enumerating the types of the constant. |
| void ValueEnumerator::EnumerateOperandType(const Value *V) { |
| EnumerateType(V->getType()); |
| if (const Constant *C = dyn_cast<Constant>(V)) { |
| // If this constant is already enumerated, ignore it, we know its type must |
| // be enumerated. |
| if (ValueMap.count(V)) return; |
| |
| // This constant may have operands, make sure to enumerate the types in |
| // them. |
| for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) |
| EnumerateOperandType(C->getOperand(i)); |
| |
| if (const MDNode *N = dyn_cast<MDNode>(V)) { |
| for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) { |
| Value *Elem = N->getElement(i); |
| if (Elem) |
| EnumerateOperandType(Elem); |
| } |
| } |
| } else if (isa<MDString>(V) || isa<MDNode>(V)) |
| EnumerateValue(V); |
| } |
| |
| void ValueEnumerator::EnumerateAttributes(const AttrListPtr &PAL) { |
| if (PAL.isEmpty()) return; // null is always 0. |
| // Do a lookup. |
| unsigned &Entry = AttributeMap[PAL.getRawPointer()]; |
| if (Entry == 0) { |
| // Never saw this before, add it. |
| Attributes.push_back(PAL); |
| Entry = Attributes.size(); |
| } |
| } |
| |
| |
| void ValueEnumerator::incorporateFunction(const Function &F) { |
| NumModuleValues = Values.size(); |
| |
| // Adding function arguments to the value table. |
| for(Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); |
| I != E; ++I) |
| EnumerateValue(I); |
| |
| FirstFuncConstantID = Values.size(); |
| |
| // Add all function-level constants to the value table. |
| for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { |
| for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) |
| for (User::const_op_iterator OI = I->op_begin(), E = I->op_end(); |
| OI != E; ++OI) { |
| if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) || |
| isa<InlineAsm>(*OI)) |
| EnumerateValue(*OI); |
| } |
| BasicBlocks.push_back(BB); |
| ValueMap[BB] = BasicBlocks.size(); |
| } |
| |
| // Optimize the constant layout. |
| OptimizeConstants(FirstFuncConstantID, Values.size()); |
| |
| // Add the function's parameter attributes so they are available for use in |
| // the function's instruction. |
| EnumerateAttributes(F.getAttributes()); |
| |
| FirstInstID = Values.size(); |
| |
| // Add all of the instructions. |
| for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { |
| for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) { |
| if (I->getType() != Type::VoidTy) |
| EnumerateValue(I); |
| } |
| } |
| } |
| |
| void ValueEnumerator::purgeFunction() { |
| /// Remove purged values from the ValueMap. |
| for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i) |
| ValueMap.erase(Values[i].first); |
| for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i) |
| ValueMap.erase(BasicBlocks[i]); |
| |
| Values.resize(NumModuleValues); |
| BasicBlocks.clear(); |
| } |
| |