| //===-- SlotCalculator.cpp - Calculate what slots values land in ----------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements a useful analysis step to figure out what numbered slots |
| // values in a program will land in (keeping track of per plane information). |
| // |
| // This is used when writing a file to disk, either in bytecode or assembly. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "SlotCalculator.h" |
| #include "llvm/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/Function.h" |
| #include "llvm/Instructions.h" |
| #include "llvm/Module.h" |
| #include "llvm/SymbolTable.h" |
| #include "llvm/Type.h" |
| #include "llvm/Analysis/ConstantsScanner.h" |
| #include "llvm/ADT/PostOrderIterator.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include <algorithm> |
| #include <functional> |
| |
| using namespace llvm; |
| |
| #if 0 |
| #include <iostream> |
| #define SC_DEBUG(X) std::cerr << X |
| #else |
| #define SC_DEBUG(X) |
| #endif |
| |
| SlotCalculator::SlotCalculator(const Module *M ) { |
| ModuleContainsAllFunctionConstants = false; |
| ModuleTypeLevel = 0; |
| TheModule = M; |
| |
| // Preload table... Make sure that all of the primitive types are in the table |
| // and that their Primitive ID is equal to their slot # |
| // |
| SC_DEBUG("Inserting primitive types:\n"); |
| for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) { |
| assert(Type::getPrimitiveType((Type::TypeID)i)); |
| insertType(Type::getPrimitiveType((Type::TypeID)i), true); |
| } |
| |
| if (M == 0) return; // Empty table... |
| processModule(); |
| } |
| |
| SlotCalculator::SlotCalculator(const Function *M ) { |
| ModuleContainsAllFunctionConstants = false; |
| TheModule = M ? M->getParent() : 0; |
| |
| // Preload table... Make sure that all of the primitive types are in the table |
| // and that their Primitive ID is equal to their slot # |
| // |
| SC_DEBUG("Inserting primitive types:\n"); |
| for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) { |
| assert(Type::getPrimitiveType((Type::TypeID)i)); |
| insertType(Type::getPrimitiveType((Type::TypeID)i), true); |
| } |
| |
| if (TheModule == 0) return; // Empty table... |
| |
| processModule(); // Process module level stuff |
| incorporateFunction(M); // Start out in incorporated state |
| } |
| |
| unsigned SlotCalculator::getGlobalSlot(const Value *V) const { |
| assert(!CompactionTable.empty() && |
| "This method can only be used when compaction is enabled!"); |
| std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V); |
| assert(I != NodeMap.end() && "Didn't find global slot entry!"); |
| return I->second; |
| } |
| |
| unsigned SlotCalculator::getGlobalSlot(const Type* T) const { |
| std::map<const Type*, unsigned>::const_iterator I = TypeMap.find(T); |
| assert(I != TypeMap.end() && "Didn't find global slot entry!"); |
| return I->second; |
| } |
| |
| SlotCalculator::TypePlane &SlotCalculator::getPlane(unsigned Plane) { |
| if (CompactionTable.empty()) { // No compaction table active? |
| // fall out |
| } else if (!CompactionTable[Plane].empty()) { // Compaction table active. |
| assert(Plane < CompactionTable.size()); |
| return CompactionTable[Plane]; |
| } else { |
| // Final case: compaction table active, but this plane is not |
| // compactified. If the type plane is compactified, unmap back to the |
| // global type plane corresponding to "Plane". |
| if (!CompactionTypes.empty()) { |
| const Type *Ty = CompactionTypes[Plane]; |
| TypeMapType::iterator It = TypeMap.find(Ty); |
| assert(It != TypeMap.end() && "Type not in global constant map?"); |
| Plane = It->second; |
| } |
| } |
| |
| // Okay we are just returning an entry out of the main Table. Make sure the |
| // plane exists and return it. |
| if (Plane >= Table.size()) |
| Table.resize(Plane+1); |
| return Table[Plane]; |
| } |
| |
| // processModule - Process all of the module level function declarations and |
| // types that are available. |
| // |
| void SlotCalculator::processModule() { |
| SC_DEBUG("begin processModule!\n"); |
| |
| // Add all of the global variables to the value table... |
| // |
| for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend(); |
| I != E; ++I) |
| getOrCreateSlot(I); |
| |
| // Scavenge the types out of the functions, then add the functions themselves |
| // to the value table... |
| // |
| for (Module::const_iterator I = TheModule->begin(), E = TheModule->end(); |
| I != E; ++I) |
| getOrCreateSlot(I); |
| |
| // Add all of the module level constants used as initializers |
| // |
| for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend(); |
| I != E; ++I) |
| if (I->hasInitializer()) |
| getOrCreateSlot(I->getInitializer()); |
| |
| // Now that all global constants have been added, rearrange constant planes |
| // that contain constant strings so that the strings occur at the start of the |
| // plane, not somewhere in the middle. |
| // |
| for (unsigned plane = 0, e = Table.size(); plane != e; ++plane) { |
| if (const ArrayType *AT = dyn_cast<ArrayType>(Types[plane])) |
| if (AT->getElementType() == Type::SByteTy || |
| AT->getElementType() == Type::UByteTy) { |
| TypePlane &Plane = Table[plane]; |
| unsigned FirstNonStringID = 0; |
| for (unsigned i = 0, e = Plane.size(); i != e; ++i) |
| if (isa<ConstantAggregateZero>(Plane[i]) || |
| (isa<ConstantArray>(Plane[i]) && |
| cast<ConstantArray>(Plane[i])->isString())) { |
| // Check to see if we have to shuffle this string around. If not, |
| // don't do anything. |
| if (i != FirstNonStringID) { |
| // Swap the plane entries.... |
| std::swap(Plane[i], Plane[FirstNonStringID]); |
| |
| // Keep the NodeMap up to date. |
| NodeMap[Plane[i]] = i; |
| NodeMap[Plane[FirstNonStringID]] = FirstNonStringID; |
| } |
| ++FirstNonStringID; |
| } |
| } |
| } |
| |
| // Scan all of the functions for their constants, which allows us to emit |
| // more compact modules. This is optional, and is just used to compactify |
| // the constants used by different functions together. |
| // |
| // This functionality tends to produce smaller bytecode files. This should |
| // not be used in the future by clients that want to, for example, build and |
| // emit functions on the fly. For now, however, it is unconditionally |
| // enabled. |
| ModuleContainsAllFunctionConstants = true; |
| |
| SC_DEBUG("Inserting function constants:\n"); |
| for (Module::const_iterator F = TheModule->begin(), E = TheModule->end(); |
| F != E; ++F) { |
| for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I){ |
| for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) |
| if (isa<Constant>(I->getOperand(op)) && |
| !isa<GlobalValue>(I->getOperand(op))) |
| getOrCreateSlot(I->getOperand(op)); |
| getOrCreateSlot(I->getType()); |
| if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I)) |
| getOrCreateSlot(VAN->getArgType()); |
| } |
| processSymbolTableConstants(&F->getSymbolTable()); |
| } |
| |
| // Insert constants that are named at module level into the slot pool so that |
| // the module symbol table can refer to them... |
| SC_DEBUG("Inserting SymbolTable values:\n"); |
| processSymbolTable(&TheModule->getSymbolTable()); |
| |
| // Now that we have collected together all of the information relevant to the |
| // module, compactify the type table if it is particularly big and outputting |
| // a bytecode file. The basic problem we run into is that some programs have |
| // a large number of types, which causes the type field to overflow its size, |
| // which causes instructions to explode in size (particularly call |
| // instructions). To avoid this behavior, we "sort" the type table so that |
| // all non-value types are pushed to the end of the type table, giving nice |
| // low numbers to the types that can be used by instructions, thus reducing |
| // the amount of explodage we suffer. |
| if (Types.size() >= 64) { |
| unsigned FirstNonValueTypeID = 0; |
| for (unsigned i = 0, e = Types.size(); i != e; ++i) |
| if (Types[i]->isFirstClassType() || Types[i]->isPrimitiveType()) { |
| // Check to see if we have to shuffle this type around. If not, don't |
| // do anything. |
| if (i != FirstNonValueTypeID) { |
| // Swap the type ID's. |
| std::swap(Types[i], Types[FirstNonValueTypeID]); |
| |
| // Keep the TypeMap up to date. |
| TypeMap[Types[i]] = i; |
| TypeMap[Types[FirstNonValueTypeID]] = FirstNonValueTypeID; |
| |
| // When we move a type, make sure to move its value plane as needed. |
| if (Table.size() > FirstNonValueTypeID) { |
| if (Table.size() <= i) Table.resize(i+1); |
| std::swap(Table[i], Table[FirstNonValueTypeID]); |
| } |
| } |
| ++FirstNonValueTypeID; |
| } |
| } |
| |
| SC_DEBUG("end processModule!\n"); |
| } |
| |
| // processSymbolTable - Insert all of the values in the specified symbol table |
| // into the values table... |
| // |
| void SlotCalculator::processSymbolTable(const SymbolTable *ST) { |
| // Do the types first. |
| for (SymbolTable::type_const_iterator TI = ST->type_begin(), |
| TE = ST->type_end(); TI != TE; ++TI ) |
| getOrCreateSlot(TI->second); |
| |
| // Now do the values. |
| for (SymbolTable::plane_const_iterator PI = ST->plane_begin(), |
| PE = ST->plane_end(); PI != PE; ++PI) |
| for (SymbolTable::value_const_iterator VI = PI->second.begin(), |
| VE = PI->second.end(); VI != VE; ++VI) |
| getOrCreateSlot(VI->second); |
| } |
| |
| void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) { |
| // Do the types first |
| for (SymbolTable::type_const_iterator TI = ST->type_begin(), |
| TE = ST->type_end(); TI != TE; ++TI ) |
| getOrCreateSlot(TI->second); |
| |
| // Now do the constant values in all planes |
| for (SymbolTable::plane_const_iterator PI = ST->plane_begin(), |
| PE = ST->plane_end(); PI != PE; ++PI) |
| for (SymbolTable::value_const_iterator VI = PI->second.begin(), |
| VE = PI->second.end(); VI != VE; ++VI) |
| if (isa<Constant>(VI->second) && |
| !isa<GlobalValue>(VI->second)) |
| getOrCreateSlot(VI->second); |
| } |
| |
| |
| void SlotCalculator::incorporateFunction(const Function *F) { |
| assert((ModuleLevel.size() == 0 || |
| ModuleTypeLevel == 0) && "Module already incorporated!"); |
| |
| SC_DEBUG("begin processFunction!\n"); |
| |
| // If we emitted all of the function constants, build a compaction table. |
| if ( ModuleContainsAllFunctionConstants) |
| buildCompactionTable(F); |
| |
| // Update the ModuleLevel entries to be accurate. |
| ModuleLevel.resize(getNumPlanes()); |
| for (unsigned i = 0, e = getNumPlanes(); i != e; ++i) |
| ModuleLevel[i] = getPlane(i).size(); |
| ModuleTypeLevel = Types.size(); |
| |
| // Iterate over function arguments, adding them to the value table... |
| for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I) |
| getOrCreateSlot(I); |
| |
| if ( !ModuleContainsAllFunctionConstants ) { |
| // Iterate over all of the instructions in the function, looking for |
| // constant values that are referenced. Add these to the value pools |
| // before any nonconstant values. This will be turned into the constant |
| // pool for the bytecode writer. |
| // |
| |
| // Emit all of the constants that are being used by the instructions in |
| // the function... |
| constant_iterator CI = constant_begin(F); |
| constant_iterator CE = constant_end(F); |
| while ( CI != CE ) { |
| this->getOrCreateSlot(*CI); |
| ++CI; |
| } |
| |
| // If there is a symbol table, it is possible that the user has names for |
| // constants that are not being used. In this case, we will have problems |
| // if we don't emit the constants now, because otherwise we will get |
| // symbol table references to constants not in the output. Scan for these |
| // constants now. |
| // |
| processSymbolTableConstants(&F->getSymbolTable()); |
| } |
| |
| SC_DEBUG("Inserting Instructions:\n"); |
| |
| // Add all of the instructions to the type planes... |
| for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) { |
| getOrCreateSlot(BB); |
| for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) { |
| getOrCreateSlot(I); |
| if (const VANextInst *VAN = dyn_cast<VANextInst>(I)) |
| getOrCreateSlot(VAN->getArgType()); |
| } |
| } |
| |
| // If we are building a compaction table, prune out planes that do not benefit |
| // from being compactified. |
| if (!CompactionTable.empty()) |
| pruneCompactionTable(); |
| |
| SC_DEBUG("end processFunction!\n"); |
| } |
| |
| void SlotCalculator::purgeFunction() { |
| assert((ModuleLevel.size() != 0 || |
| ModuleTypeLevel != 0) && "Module not incorporated!"); |
| unsigned NumModuleTypes = ModuleLevel.size(); |
| |
| SC_DEBUG("begin purgeFunction!\n"); |
| |
| // First, free the compaction map if used. |
| CompactionNodeMap.clear(); |
| CompactionTypeMap.clear(); |
| |
| // Next, remove values from existing type planes |
| for (unsigned i = 0; i != NumModuleTypes; ++i) { |
| // Size of plane before function came |
| unsigned ModuleLev = getModuleLevel(i); |
| assert(int(ModuleLev) >= 0 && "BAD!"); |
| |
| TypePlane &Plane = getPlane(i); |
| |
| assert(ModuleLev <= Plane.size() && "module levels higher than elements?"); |
| while (Plane.size() != ModuleLev) { |
| assert(!isa<GlobalValue>(Plane.back()) && |
| "Functions cannot define globals!"); |
| NodeMap.erase(Plane.back()); // Erase from nodemap |
| Plane.pop_back(); // Shrink plane |
| } |
| } |
| |
| // We don't need this state anymore, free it up. |
| ModuleLevel.clear(); |
| ModuleTypeLevel = 0; |
| |
| // Finally, remove any type planes defined by the function... |
| CompactionTypes.clear(); |
| if (!CompactionTable.empty()) { |
| CompactionTable.clear(); |
| } else { |
| while (Table.size() > NumModuleTypes) { |
| TypePlane &Plane = Table.back(); |
| SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size " |
| << Plane.size() << "\n"); |
| while (Plane.size()) { |
| assert(!isa<GlobalValue>(Plane.back()) && |
| "Functions cannot define globals!"); |
| NodeMap.erase(Plane.back()); // Erase from nodemap |
| Plane.pop_back(); // Shrink plane |
| } |
| |
| Table.pop_back(); // Nuke the plane, we don't like it. |
| } |
| } |
| |
| SC_DEBUG("end purgeFunction!\n"); |
| } |
| |
| static inline bool hasNullValue(unsigned TyID) { |
| return TyID != Type::LabelTyID && TyID != Type::VoidTyID; |
| } |
| |
| /// getOrCreateCompactionTableSlot - This method is used to build up the initial |
| /// approximation of the compaction table. |
| unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Value *V) { |
| std::map<const Value*, unsigned>::iterator I = |
| CompactionNodeMap.lower_bound(V); |
| if (I != CompactionNodeMap.end() && I->first == V) |
| return I->second; // Already exists? |
| |
| // Make sure the type is in the table. |
| unsigned Ty; |
| if (!CompactionTypes.empty()) |
| Ty = getOrCreateCompactionTableSlot(V->getType()); |
| else // If the type plane was decompactified, use the global plane ID |
| Ty = getSlot(V->getType()); |
| if (CompactionTable.size() <= Ty) |
| CompactionTable.resize(Ty+1); |
| |
| TypePlane &TyPlane = CompactionTable[Ty]; |
| |
| // Make sure to insert the null entry if the thing we are inserting is not a |
| // null constant. |
| if (TyPlane.empty() && hasNullValue(V->getType()->getTypeID())) { |
| Value *ZeroInitializer = Constant::getNullValue(V->getType()); |
| if (V != ZeroInitializer) { |
| TyPlane.push_back(ZeroInitializer); |
| CompactionNodeMap[ZeroInitializer] = 0; |
| } |
| } |
| |
| unsigned SlotNo = TyPlane.size(); |
| TyPlane.push_back(V); |
| CompactionNodeMap.insert(std::make_pair(V, SlotNo)); |
| return SlotNo; |
| } |
| |
| /// getOrCreateCompactionTableSlot - This method is used to build up the initial |
| /// approximation of the compaction table. |
| unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Type *T) { |
| std::map<const Type*, unsigned>::iterator I = |
| CompactionTypeMap.lower_bound(T); |
| if (I != CompactionTypeMap.end() && I->first == T) |
| return I->second; // Already exists? |
| |
| unsigned SlotNo = CompactionTypes.size(); |
| SC_DEBUG("Inserting Compaction Type #" << SlotNo << ": " << T << "\n"); |
| CompactionTypes.push_back(T); |
| CompactionTypeMap.insert(std::make_pair(T, SlotNo)); |
| return SlotNo; |
| } |
| |
| /// buildCompactionTable - Since all of the function constants and types are |
| /// stored in the module-level constant table, we don't need to emit a function |
| /// constant table. Also due to this, the indices for various constants and |
| /// types might be very large in large programs. In order to avoid blowing up |
| /// the size of instructions in the bytecode encoding, we build a compaction |
| /// table, which defines a mapping from function-local identifiers to global |
| /// identifiers. |
| void SlotCalculator::buildCompactionTable(const Function *F) { |
| assert(CompactionNodeMap.empty() && "Compaction table already built!"); |
| assert(CompactionTypeMap.empty() && "Compaction types already built!"); |
| // First step, insert the primitive types. |
| CompactionTable.resize(Type::LastPrimitiveTyID+1); |
| for (unsigned i = 0; i <= Type::LastPrimitiveTyID; ++i) { |
| const Type *PrimTy = Type::getPrimitiveType((Type::TypeID)i); |
| CompactionTypes.push_back(PrimTy); |
| CompactionTypeMap[PrimTy] = i; |
| } |
| |
| // Next, include any types used by function arguments. |
| for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I) |
| getOrCreateCompactionTableSlot(I->getType()); |
| |
| // Next, find all of the types and values that are referred to by the |
| // instructions in the function. |
| for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) { |
| getOrCreateCompactionTableSlot(I->getType()); |
| for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) |
| if (isa<Constant>(I->getOperand(op))) |
| getOrCreateCompactionTableSlot(I->getOperand(op)); |
| if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I)) |
| getOrCreateCompactionTableSlot(VAN->getArgType()); |
| } |
| |
| // Do the types in the symbol table |
| const SymbolTable &ST = F->getSymbolTable(); |
| for (SymbolTable::type_const_iterator TI = ST.type_begin(), |
| TE = ST.type_end(); TI != TE; ++TI) |
| getOrCreateCompactionTableSlot(TI->second); |
| |
| // Now do the constants and global values |
| for (SymbolTable::plane_const_iterator PI = ST.plane_begin(), |
| PE = ST.plane_end(); PI != PE; ++PI) |
| for (SymbolTable::value_const_iterator VI = PI->second.begin(), |
| VE = PI->second.end(); VI != VE; ++VI) |
| if (isa<Constant>(VI->second) && !isa<GlobalValue>(VI->second)) |
| getOrCreateCompactionTableSlot(VI->second); |
| |
| // Now that we have all of the values in the table, and know what types are |
| // referenced, make sure that there is at least the zero initializer in any |
| // used type plane. Since the type was used, we will be emitting instructions |
| // to the plane even if there are no constants in it. |
| CompactionTable.resize(CompactionTypes.size()); |
| for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i) |
| if (CompactionTable[i].empty() && (i != Type::VoidTyID) && |
| i != Type::LabelTyID) { |
| const Type *Ty = CompactionTypes[i]; |
| SC_DEBUG("Getting Null Value #" << i << " for Type " << Ty << "\n"); |
| assert(Ty->getTypeID() != Type::VoidTyID); |
| assert(Ty->getTypeID() != Type::LabelTyID); |
| getOrCreateCompactionTableSlot(Constant::getNullValue(Ty)); |
| } |
| |
| // Okay, now at this point, we have a legal compaction table. Since we want |
| // to emit the smallest possible binaries, do not compactify the type plane if |
| // it will not save us anything. Because we have not yet incorporated the |
| // function body itself yet, we don't know whether or not it's a good idea to |
| // compactify other planes. We will defer this decision until later. |
| TypeList &GlobalTypes = Types; |
| |
| // All of the values types will be scrunched to the start of the types plane |
| // of the global table. Figure out just how many there are. |
| assert(!GlobalTypes.empty() && "No global types???"); |
| unsigned NumFCTypes = GlobalTypes.size()-1; |
| while (!GlobalTypes[NumFCTypes]->isFirstClassType()) |
| --NumFCTypes; |
| |
| // If there are fewer that 64 types, no instructions will be exploded due to |
| // the size of the type operands. Thus there is no need to compactify types. |
| // Also, if the compaction table contains most of the entries in the global |
| // table, there really is no reason to compactify either. |
| if (NumFCTypes < 64) { |
| // Decompactifying types is tricky, because we have to move type planes all |
| // over the place. At least we don't need to worry about updating the |
| // CompactionNodeMap for non-types though. |
| std::vector<TypePlane> TmpCompactionTable; |
| std::swap(CompactionTable, TmpCompactionTable); |
| TypeList TmpTypes; |
| std::swap(TmpTypes, CompactionTypes); |
| |
| // Move each plane back over to the uncompactified plane |
| while (!TmpTypes.empty()) { |
| const Type *Ty = TmpTypes.back(); |
| TmpTypes.pop_back(); |
| CompactionTypeMap.erase(Ty); // Decompactify type! |
| |
| // Find the global slot number for this type. |
| int TySlot = getSlot(Ty); |
| assert(TySlot != -1 && "Type doesn't exist in global table?"); |
| |
| // Now we know where to put the compaction table plane. |
| if (CompactionTable.size() <= unsigned(TySlot)) |
| CompactionTable.resize(TySlot+1); |
| // Move the plane back into the compaction table. |
| std::swap(CompactionTable[TySlot], TmpCompactionTable[TmpTypes.size()]); |
| |
| // And remove the empty plane we just moved in. |
| TmpCompactionTable.pop_back(); |
| } |
| } |
| } |
| |
| |
| /// pruneCompactionTable - Once the entire function being processed has been |
| /// incorporated into the current compaction table, look over the compaction |
| /// table and check to see if there are any values whose compaction will not |
| /// save us any space in the bytecode file. If compactifying these values |
| /// serves no purpose, then we might as well not even emit the compactification |
| /// information to the bytecode file, saving a bit more space. |
| /// |
| /// Note that the type plane has already been compactified if possible. |
| /// |
| void SlotCalculator::pruneCompactionTable() { |
| TypeList &TyPlane = CompactionTypes; |
| for (unsigned ctp = 0, e = CompactionTable.size(); ctp != e; ++ctp) |
| if (!CompactionTable[ctp].empty()) { |
| TypePlane &CPlane = CompactionTable[ctp]; |
| unsigned GlobalSlot = ctp; |
| if (!TyPlane.empty()) |
| GlobalSlot = getGlobalSlot(TyPlane[ctp]); |
| |
| if (GlobalSlot >= Table.size()) |
| Table.resize(GlobalSlot+1); |
| TypePlane &GPlane = Table[GlobalSlot]; |
| |
| unsigned ModLevel = getModuleLevel(ctp); |
| unsigned NumFunctionObjs = CPlane.size()-ModLevel; |
| |
| // If the maximum index required if all entries in this plane were merged |
| // into the global plane is less than 64, go ahead and eliminate the |
| // plane. |
| bool PrunePlane = GPlane.size() + NumFunctionObjs < 64; |
| |
| // If there are no function-local values defined, and the maximum |
| // referenced global entry is less than 64, we don't need to compactify. |
| if (!PrunePlane && NumFunctionObjs == 0) { |
| unsigned MaxIdx = 0; |
| for (unsigned i = 0; i != ModLevel; ++i) { |
| unsigned Idx = NodeMap[CPlane[i]]; |
| if (Idx > MaxIdx) MaxIdx = Idx; |
| } |
| PrunePlane = MaxIdx < 64; |
| } |
| |
| // Ok, finally, if we decided to prune this plane out of the compaction |
| // table, do so now. |
| if (PrunePlane) { |
| TypePlane OldPlane; |
| std::swap(OldPlane, CPlane); |
| |
| // Loop over the function local objects, relocating them to the global |
| // table plane. |
| for (unsigned i = ModLevel, e = OldPlane.size(); i != e; ++i) { |
| const Value *V = OldPlane[i]; |
| CompactionNodeMap.erase(V); |
| assert(NodeMap.count(V) == 0 && "Value already in table??"); |
| getOrCreateSlot(V); |
| } |
| |
| // For compactified global values, just remove them from the compaction |
| // node map. |
| for (unsigned i = 0; i != ModLevel; ++i) |
| CompactionNodeMap.erase(OldPlane[i]); |
| |
| // Update the new modulelevel for this plane. |
| assert(ctp < ModuleLevel.size() && "Cannot set modulelevel!"); |
| ModuleLevel[ctp] = GPlane.size()-NumFunctionObjs; |
| assert((int)ModuleLevel[ctp] >= 0 && "Bad computation!"); |
| } |
| } |
| } |
| |
| /// Determine if the compaction table is actually empty. Because the |
| /// compaction table always includes the primitive type planes, we |
| /// can't just check getCompactionTable().size() because it will never |
| /// be zero. Furthermore, the ModuleLevel factors into whether a given |
| /// plane is empty or not. This function does the necessary computation |
| /// to determine if its actually empty. |
| bool SlotCalculator::CompactionTableIsEmpty() const { |
| // Check a degenerate case, just in case. |
| if (CompactionTable.size() == 0) return true; |
| |
| // Check each plane |
| for (unsigned i = 0, e = CompactionTable.size(); i < e; ++i) { |
| // If the plane is not empty |
| if (!CompactionTable[i].empty()) { |
| // If the module level is non-zero then at least the |
| // first element of the plane is valid and therefore not empty. |
| unsigned End = getModuleLevel(i); |
| if (End != 0) |
| return false; |
| } |
| } |
| // All the compaction table planes are empty so the table is |
| // considered empty too. |
| return true; |
| } |
| |
| int SlotCalculator::getSlot(const Value *V) const { |
| // If there is a CompactionTable active... |
| if (!CompactionNodeMap.empty()) { |
| std::map<const Value*, unsigned>::const_iterator I = |
| CompactionNodeMap.find(V); |
| if (I != CompactionNodeMap.end()) |
| return (int)I->second; |
| // Otherwise, if it's not in the compaction table, it must be in a |
| // non-compactified plane. |
| } |
| |
| std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V); |
| if (I != NodeMap.end()) |
| return (int)I->second; |
| |
| return -1; |
| } |
| |
| int SlotCalculator::getSlot(const Type*T) const { |
| // If there is a CompactionTable active... |
| if (!CompactionTypeMap.empty()) { |
| std::map<const Type*, unsigned>::const_iterator I = |
| CompactionTypeMap.find(T); |
| if (I != CompactionTypeMap.end()) |
| return (int)I->second; |
| // Otherwise, if it's not in the compaction table, it must be in a |
| // non-compactified plane. |
| } |
| |
| std::map<const Type*, unsigned>::const_iterator I = TypeMap.find(T); |
| if (I != TypeMap.end()) |
| return (int)I->second; |
| |
| return -1; |
| } |
| |
| int SlotCalculator::getOrCreateSlot(const Value *V) { |
| if (V->getType() == Type::VoidTy) return -1; |
| |
| int SlotNo = getSlot(V); // Check to see if it's already in! |
| if (SlotNo != -1) return SlotNo; |
| |
| if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) |
| assert(GV->getParent() != 0 && "Global not embedded into a module!"); |
| |
| if (!isa<GlobalValue>(V)) // Initializers for globals are handled explicitly |
| if (const Constant *C = dyn_cast<Constant>(V)) { |
| assert(CompactionNodeMap.empty() && |
| "All needed constants should be in the compaction map already!"); |
| |
| // Do not index the characters that make up constant strings. We emit |
| // constant strings as special entities that don't require their |
| // individual characters to be emitted. |
| if (!isa<ConstantArray>(C) || !cast<ConstantArray>(C)->isString()) { |
| // This makes sure that if a constant has uses (for example an array of |
| // const ints), that they are inserted also. |
| // |
| for (User::const_op_iterator I = C->op_begin(), E = C->op_end(); |
| I != E; ++I) |
| getOrCreateSlot(*I); |
| } else { |
| assert(ModuleLevel.empty() && |
| "How can a constant string be directly accessed in a function?"); |
| // Otherwise, if we are emitting a bytecode file and this IS a string, |
| // remember it. |
| if (!C->isNullValue()) |
| ConstantStrings.push_back(cast<ConstantArray>(C)); |
| } |
| } |
| |
| return insertValue(V); |
| } |
| |
| int SlotCalculator::getOrCreateSlot(const Type* T) { |
| int SlotNo = getSlot(T); // Check to see if it's already in! |
| if (SlotNo != -1) return SlotNo; |
| return insertType(T); |
| } |
| |
| int SlotCalculator::insertValue(const Value *D, bool dontIgnore) { |
| assert(D && "Can't insert a null value!"); |
| assert(getSlot(D) == -1 && "Value is already in the table!"); |
| |
| // If we are building a compaction map, and if this plane is being compacted, |
| // insert the value into the compaction map, not into the global map. |
| if (!CompactionNodeMap.empty()) { |
| if (D->getType() == Type::VoidTy) return -1; // Do not insert void values |
| assert(!isa<Constant>(D) && |
| "Types, constants, and globals should be in global table!"); |
| |
| int Plane = getSlot(D->getType()); |
| assert(Plane != -1 && CompactionTable.size() > (unsigned)Plane && |
| "Didn't find value type!"); |
| if (!CompactionTable[Plane].empty()) |
| return getOrCreateCompactionTableSlot(D); |
| } |
| |
| // If this node does not contribute to a plane, or if the node has a |
| // name and we don't want names, then ignore the silly node... Note that types |
| // do need slot numbers so that we can keep track of where other values land. |
| // |
| if (!dontIgnore) // Don't ignore nonignorables! |
| if (D->getType() == Type::VoidTy ) { // Ignore void type nodes |
| SC_DEBUG("ignored value " << *D << "\n"); |
| return -1; // We do need types unconditionally though |
| } |
| |
| // Okay, everything is happy, actually insert the silly value now... |
| return doInsertValue(D); |
| } |
| |
| int SlotCalculator::insertType(const Type *Ty, bool dontIgnore) { |
| assert(Ty && "Can't insert a null type!"); |
| assert(getSlot(Ty) == -1 && "Type is already in the table!"); |
| |
| // If we are building a compaction map, and if this plane is being compacted, |
| // insert the value into the compaction map, not into the global map. |
| if (!CompactionTypeMap.empty()) { |
| getOrCreateCompactionTableSlot(Ty); |
| } |
| |
| // Insert the current type before any subtypes. This is important because |
| // recursive types elements are inserted in a bottom up order. Changing |
| // this here can break things. For example: |
| // |
| // global { \2 * } { { \2 }* null } |
| // |
| int ResultSlot = doInsertType(Ty); |
| SC_DEBUG(" Inserted type: " << Ty->getDescription() << " slot=" << |
| ResultSlot << "\n"); |
| |
| // Loop over any contained types in the definition... in post |
| // order. |
| for (po_iterator<const Type*> I = po_begin(Ty), E = po_end(Ty); |
| I != E; ++I) { |
| if (*I != Ty) { |
| const Type *SubTy = *I; |
| // If we haven't seen this sub type before, add it to our type table! |
| if (getSlot(SubTy) == -1) { |
| SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n"); |
| doInsertType(SubTy); |
| SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() << "\n"); |
| } |
| } |
| } |
| return ResultSlot; |
| } |
| |
| // doInsertValue - This is a small helper function to be called only |
| // be insertValue. |
| // |
| int SlotCalculator::doInsertValue(const Value *D) { |
| const Type *Typ = D->getType(); |
| unsigned Ty; |
| |
| // Used for debugging DefSlot=-1 assertion... |
| //if (Typ == Type::TypeTy) |
| // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n"; |
| |
| if (Typ->isDerivedType()) { |
| int ValSlot; |
| if (CompactionTable.empty()) |
| ValSlot = getSlot(Typ); |
| else |
| ValSlot = getGlobalSlot(Typ); |
| if (ValSlot == -1) { // Have we already entered this type? |
| // Nope, this is the first we have seen the type, process it. |
| ValSlot = insertType(Typ, true); |
| assert(ValSlot != -1 && "ProcessType returned -1 for a type?"); |
| } |
| Ty = (unsigned)ValSlot; |
| } else { |
| Ty = Typ->getTypeID(); |
| } |
| |
| if (Table.size() <= Ty) // Make sure we have the type plane allocated... |
| Table.resize(Ty+1, TypePlane()); |
| |
| // If this is the first value to get inserted into the type plane, make sure |
| // to insert the implicit null value... |
| if (Table[Ty].empty() && hasNullValue(Ty)) { |
| Value *ZeroInitializer = Constant::getNullValue(Typ); |
| |
| // If we are pushing zeroinit, it will be handled below. |
| if (D != ZeroInitializer) { |
| Table[Ty].push_back(ZeroInitializer); |
| NodeMap[ZeroInitializer] = 0; |
| } |
| } |
| |
| // Insert node into table and NodeMap... |
| unsigned DestSlot = NodeMap[D] = Table[Ty].size(); |
| Table[Ty].push_back(D); |
| |
| SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" << |
| DestSlot << " ["); |
| // G = Global, C = Constant, T = Type, F = Function, o = other |
| SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" : |
| (isa<Function>(D) ? "F" : "o")))); |
| SC_DEBUG("]\n"); |
| return (int)DestSlot; |
| } |
| |
| // doInsertType - This is a small helper function to be called only |
| // be insertType. |
| // |
| int SlotCalculator::doInsertType(const Type *Ty) { |
| |
| // Insert node into table and NodeMap... |
| unsigned DestSlot = TypeMap[Ty] = Types.size(); |
| Types.push_back(Ty); |
| |
| SC_DEBUG(" Inserting type [" << DestSlot << "] = " << Ty << "\n" ); |
| return (int)DestSlot; |
| } |
| |
| // vim: sw=2 ai |