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Diffstat (limited to 'lib/Bytecode/Writer/SlotCalculator.cpp')
| -rw-r--r-- | lib/Bytecode/Writer/SlotCalculator.cpp | 862 |
1 files changed, 862 insertions, 0 deletions
diff --git a/lib/Bytecode/Writer/SlotCalculator.cpp b/lib/Bytecode/Writer/SlotCalculator.cpp new file mode 100644 index 0000000000..c6aba09fe5 --- /dev/null +++ b/lib/Bytecode/Writer/SlotCalculator.cpp @@ -0,0 +1,862 @@ +//===-- 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_global_iterator I = TheModule->global_begin(), + E = TheModule->global_end(); 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_global_iterator I = TheModule->global_begin(), + E = TheModule->global_end(); 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()); + } + 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_arg_iterator I = F->arg_begin(), E = F->arg_end(); 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 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(const Type *Ty) { + return Ty != Type::LabelTy && Ty != Type::VoidTy && !isa<OpaqueType>(Ty); +} + +/// 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())) { + 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_arg_iterator I = F->arg_begin(), E = F->arg_end(); + 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)); + } + + // 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(Typ)) { + 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; +} + |