1 //===-- SlotCalculator.cpp - Calculate what slots values land in ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a useful analysis step to figure out what numbered
11 // slots values in a program will land in (keeping track of per plane
12 // information as required.
14 // This is used primarily for when writing a file to disk, either in bytecode
17 //===----------------------------------------------------------------------===//
19 #include "llvm/SlotCalculator.h"
20 #include "llvm/Analysis/ConstantsScanner.h"
21 #include "llvm/Module.h"
22 #include "llvm/iOther.h"
23 #include "llvm/Constant.h"
24 #include "llvm/DerivedTypes.h"
25 #include "llvm/SymbolTable.h"
26 #include "Support/PostOrderIterator.h"
27 #include "Support/STLExtras.h"
32 #define SC_DEBUG(X) std::cerr << X
37 SlotCalculator::SlotCalculator(const Module *M, bool IgnoreNamed) {
38 IgnoreNamedNodes = IgnoreNamed;
41 // Preload table... Make sure that all of the primitive types are in the table
42 // and that their Primitive ID is equal to their slot #
44 SC_DEBUG("Inserting primitive types:\n");
45 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
46 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
47 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
50 if (M == 0) return; // Empty table...
54 SlotCalculator::SlotCalculator(const Function *M, bool IgnoreNamed) {
55 IgnoreNamedNodes = IgnoreNamed;
56 TheModule = M ? M->getParent() : 0;
58 // Preload table... Make sure that all of the primitive types are in the table
59 // and that their Primitive ID is equal to their slot #
61 SC_DEBUG("Inserting primitive types:\n");
62 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
63 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
64 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
67 if (TheModule == 0) return; // Empty table...
69 processModule(); // Process module level stuff
70 incorporateFunction(M); // Start out in incorporated state
74 // processModule - Process all of the module level function declarations and
75 // types that are available.
77 void SlotCalculator::processModule() {
78 SC_DEBUG("begin processModule!\n");
80 // Add all of the global variables to the value table...
82 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
86 // Scavenge the types out of the functions, then add the functions themselves
87 // to the value table...
89 for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
93 // Add all of the module level constants used as initializers
95 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
97 if (I->hasInitializer())
98 getOrCreateSlot(I->getInitializer());
100 // Insert constants that are named at module level into the slot pool so that
101 // the module symbol table can refer to them...
103 if (!IgnoreNamedNodes) {
104 SC_DEBUG("Inserting SymbolTable values:\n");
105 processSymbolTable(&TheModule->getSymbolTable());
108 SC_DEBUG("end processModule!\n");
111 // processSymbolTable - Insert all of the values in the specified symbol table
112 // into the values table...
114 void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
115 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
116 for (SymbolTable::type_const_iterator TI = I->second.begin(),
117 TE = I->second.end(); TI != TE; ++TI)
118 getOrCreateSlot(TI->second);
121 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
122 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
123 for (SymbolTable::type_const_iterator TI = I->second.begin(),
124 TE = I->second.end(); TI != TE; ++TI)
125 if (isa<Constant>(TI->second))
126 getOrCreateSlot(TI->second);
130 void SlotCalculator::incorporateFunction(const Function *F) {
131 assert(ModuleLevel.size() == 0 && "Module already incorporated!");
133 SC_DEBUG("begin processFunction!\n");
135 // Save the Table state before we process the function...
136 for (unsigned i = 0; i < Table.size(); ++i)
137 ModuleLevel.push_back(Table[i].size());
139 SC_DEBUG("Inserting function arguments\n");
141 // Iterate over function arguments, adding them to the value table...
142 for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
145 // Iterate over all of the instructions in the function, looking for constant
146 // values that are referenced. Add these to the value pools before any
147 // nonconstant values. This will be turned into the constant pool for the
150 if (!IgnoreNamedNodes) { // Assembly writer does not need this!
151 SC_DEBUG("Inserting function constants:\n";
152 for (constant_iterator I = constant_begin(F), E = constant_end(F);
154 std::cerr << " " << *I->getType() << " " << *I << "\n";
157 // Emit all of the constants that are being used by the instructions in the
159 for_each(constant_begin(F), constant_end(F),
160 bind_obj(this, &SlotCalculator::getOrCreateSlot));
162 // If there is a symbol table, it is possible that the user has names for
163 // constants that are not being used. In this case, we will have problems
164 // if we don't emit the constants now, because otherwise we will get
165 // symboltable references to constants not in the output. Scan for these
168 processSymbolTableConstants(&F->getSymbolTable());
171 SC_DEBUG("Inserting Labels:\n");
173 // Iterate over basic blocks, adding them to the value table...
174 for (Function::const_iterator I = F->begin(), E = F->end(); I != E; ++I)
177 SC_DEBUG("Inserting Instructions:\n");
179 // Add all of the instructions to the type planes...
180 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
181 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
183 if (const VANextInst *VAN = dyn_cast<VANextInst>(I))
184 getOrCreateSlot(VAN->getArgType());
187 if (!IgnoreNamedNodes) {
188 SC_DEBUG("Inserting SymbolTable values:\n");
189 processSymbolTable(&F->getSymbolTable());
192 SC_DEBUG("end processFunction!\n");
195 void SlotCalculator::purgeFunction() {
196 assert(ModuleLevel.size() != 0 && "Module not incorporated!");
197 unsigned NumModuleTypes = ModuleLevel.size();
199 SC_DEBUG("begin purgeFunction!\n");
201 // First, remove values from existing type planes
202 for (unsigned i = 0; i < NumModuleTypes; ++i) {
203 unsigned ModuleSize = ModuleLevel[i]; // Size of plane before function came
204 TypePlane &CurPlane = Table[i];
205 //SC_DEBUG("Processing Plane " <<i<< " of size " << CurPlane.size() <<"\n");
207 while (CurPlane.size() != ModuleSize) {
208 //SC_DEBUG(" Removing [" << i << "] Value=" << CurPlane.back() << "\n");
209 std::map<const Value *, unsigned>::iterator NI =
210 NodeMap.find(CurPlane.back());
211 assert(NI != NodeMap.end() && "Node not in nodemap?");
212 NodeMap.erase(NI); // Erase from nodemap
213 CurPlane.pop_back(); // Shrink plane
217 // We don't need this state anymore, free it up.
220 // Next, remove any type planes defined by the function...
221 while (NumModuleTypes != Table.size()) {
222 TypePlane &Plane = Table.back();
223 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
224 << Plane.size() << "\n");
225 while (Plane.size()) {
226 NodeMap.erase(NodeMap.find(Plane.back())); // Erase from nodemap
227 Plane.pop_back(); // Shrink plane
230 Table.pop_back(); // Nuke the plane, we don't like it.
233 SC_DEBUG("end purgeFunction!\n");
236 int SlotCalculator::getSlot(const Value *D) const {
237 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(D);
238 if (I == NodeMap.end()) return -1;
240 return (int)I->second;
244 int SlotCalculator::getOrCreateSlot(const Value *V) {
245 int SlotNo = getSlot(V); // Check to see if it's already in!
246 if (SlotNo != -1) return SlotNo;
248 if (!isa<GlobalValue>(V))
249 if (const Constant *C = dyn_cast<Constant>(V)) {
250 // This makes sure that if a constant has uses (for example an array of
251 // const ints), that they are inserted also.
253 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
258 return insertValue(V);
262 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
263 assert(D && "Can't insert a null value!");
264 assert(getSlot(D) == -1 && "Value is already in the table!");
266 // If this node does not contribute to a plane, or if the node has a
267 // name and we don't want names, then ignore the silly node... Note that types
268 // do need slot numbers so that we can keep track of where other values land.
270 if (!dontIgnore) // Don't ignore nonignorables!
271 if (D->getType() == Type::VoidTy || // Ignore void type nodes
272 (IgnoreNamedNodes && // Ignore named and constants
273 (D->hasName() || isa<Constant>(D)) && !isa<Type>(D))) {
274 SC_DEBUG("ignored value " << *D << "\n");
275 return -1; // We do need types unconditionally though
278 // If it's a type, make sure that all subtypes of the type are included...
279 if (const Type *TheTy = dyn_cast<Type>(D)) {
281 // Insert the current type before any subtypes. This is important because
282 // recursive types elements are inserted in a bottom up order. Changing
283 // this here can break things. For example:
285 // global { \2 * } { { \2 }* null }
287 int ResultSlot = doInsertValue(TheTy);
288 SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
291 // Loop over any contained types in the definition... in post
294 for (po_iterator<const Type*> I = po_begin(TheTy), E = po_end(TheTy);
297 const Type *SubTy = *I;
298 // If we haven't seen this sub type before, add it to our type table!
299 if (getSlot(SubTy) == -1) {
300 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
301 int Slot = doInsertValue(SubTy);
302 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
303 " slot=" << Slot << "\n");
310 // Okay, everything is happy, actually insert the silly value now...
311 return doInsertValue(D);
315 // doInsertValue - This is a small helper function to be called only
318 int SlotCalculator::doInsertValue(const Value *D) {
319 const Type *Typ = D->getType();
322 // Used for debugging DefSlot=-1 assertion...
323 //if (Typ == Type::TypeTy)
324 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
326 if (Typ->isDerivedType()) {
327 int ValSlot = getSlot(Typ);
328 if (ValSlot == -1) { // Have we already entered this type?
329 // Nope, this is the first we have seen the type, process it.
330 ValSlot = insertValue(Typ, true);
331 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
333 Ty = (unsigned)ValSlot;
335 Ty = Typ->getPrimitiveID();
338 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
339 Table.resize(Ty+1, TypePlane());
341 // If this is the first value to get inserted into the type plane, make sure
342 // to insert the implicit null value...
343 if (Table[Ty].empty() && Ty >= Type::FirstDerivedTyID && !IgnoreNamedNodes) {
344 Value *ZeroInitializer = Constant::getNullValue(Typ);
346 // If we are pushing zeroinit, it will be handled below.
347 if (D != ZeroInitializer) {
348 Table[Ty].push_back(ZeroInitializer);
349 NodeMap[ZeroInitializer] = 0;
353 // Insert node into table and NodeMap...
354 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
355 Table[Ty].push_back(D);
357 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
359 // G = Global, C = Constant, T = Type, F = Function, o = other
360 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
361 (isa<Type>(D) ? "T" : (isa<Function>(D) ? "F" : "o")))));
363 return (int)DestSlot;