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"
33 #define SC_DEBUG(X) std::cerr << X
38 SlotCalculator::SlotCalculator(const Module *M, bool IgnoreNamed) {
39 IgnoreNamedNodes = IgnoreNamed;
42 // Preload table... Make sure that all of the primitive types are in the table
43 // and that their Primitive ID is equal to their slot #
45 SC_DEBUG("Inserting primitive types:\n");
46 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
47 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
48 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
51 if (M == 0) return; // Empty table...
55 SlotCalculator::SlotCalculator(const Function *M, bool IgnoreNamed) {
56 IgnoreNamedNodes = IgnoreNamed;
57 TheModule = M ? M->getParent() : 0;
59 // Preload table... Make sure that all of the primitive types are in the table
60 // and that their Primitive ID is equal to their slot #
62 SC_DEBUG("Inserting primitive types:\n");
63 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
64 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
65 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
68 if (TheModule == 0) return; // Empty table...
70 processModule(); // Process module level stuff
71 incorporateFunction(M); // Start out in incorporated state
75 // processModule - Process all of the module level function declarations and
76 // types that are available.
78 void SlotCalculator::processModule() {
79 SC_DEBUG("begin processModule!\n");
81 // Add all of the global variables to the value table...
83 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
87 // Scavenge the types out of the functions, then add the functions themselves
88 // to the value table...
90 for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
94 // Add all of the module level constants used as initializers
96 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
98 if (I->hasInitializer())
99 getOrCreateSlot(I->getInitializer());
101 // Insert constants that are named at module level into the slot pool so that
102 // the module symbol table can refer to them...
104 if (!IgnoreNamedNodes) {
105 SC_DEBUG("Inserting SymbolTable values:\n");
106 processSymbolTable(&TheModule->getSymbolTable());
109 SC_DEBUG("end processModule!\n");
112 // processSymbolTable - Insert all of the values in the specified symbol table
113 // into the values table...
115 void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
116 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
117 for (SymbolTable::type_const_iterator TI = I->second.begin(),
118 TE = I->second.end(); TI != TE; ++TI)
119 getOrCreateSlot(TI->second);
122 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
123 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
124 for (SymbolTable::type_const_iterator TI = I->second.begin(),
125 TE = I->second.end(); TI != TE; ++TI)
126 if (isa<Constant>(TI->second))
127 getOrCreateSlot(TI->second);
131 void SlotCalculator::incorporateFunction(const Function *F) {
132 assert(ModuleLevel.size() == 0 && "Module already incorporated!");
134 SC_DEBUG("begin processFunction!\n");
136 // Save the Table state before we process the function...
137 for (unsigned i = 0; i < Table.size(); ++i)
138 ModuleLevel.push_back(Table[i].size());
140 SC_DEBUG("Inserting function arguments\n");
142 // Iterate over function arguments, adding them to the value table...
143 for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
146 // Iterate over all of the instructions in the function, looking for constant
147 // values that are referenced. Add these to the value pools before any
148 // nonconstant values. This will be turned into the constant pool for the
151 if (!IgnoreNamedNodes) { // Assembly writer does not need this!
152 SC_DEBUG("Inserting function constants:\n";
153 for (constant_iterator I = constant_begin(F), E = constant_end(F);
155 std::cerr << " " << *I->getType() << " " << *I << "\n";
158 // Emit all of the constants that are being used by the instructions in the
160 for_each(constant_begin(F), constant_end(F),
161 bind_obj(this, &SlotCalculator::getOrCreateSlot));
163 // If there is a symbol table, it is possible that the user has names for
164 // constants that are not being used. In this case, we will have problems
165 // if we don't emit the constants now, because otherwise we will get
166 // symboltable references to constants not in the output. Scan for these
169 processSymbolTableConstants(&F->getSymbolTable());
172 SC_DEBUG("Inserting Labels:\n");
174 // Iterate over basic blocks, adding them to the value table...
175 for (Function::const_iterator I = F->begin(), E = F->end(); I != E; ++I)
178 SC_DEBUG("Inserting Instructions:\n");
180 // Add all of the instructions to the type planes...
181 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
182 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
184 if (const VANextInst *VAN = dyn_cast<VANextInst>(I))
185 getOrCreateSlot(VAN->getArgType());
188 if (!IgnoreNamedNodes) {
189 SC_DEBUG("Inserting SymbolTable values:\n");
190 processSymbolTable(&F->getSymbolTable());
193 SC_DEBUG("end processFunction!\n");
196 void SlotCalculator::purgeFunction() {
197 assert(ModuleLevel.size() != 0 && "Module not incorporated!");
198 unsigned NumModuleTypes = ModuleLevel.size();
200 SC_DEBUG("begin purgeFunction!\n");
202 // First, remove values from existing type planes
203 for (unsigned i = 0; i < NumModuleTypes; ++i) {
204 unsigned ModuleSize = ModuleLevel[i]; // Size of plane before function came
205 TypePlane &CurPlane = Table[i];
206 //SC_DEBUG("Processing Plane " <<i<< " of size " << CurPlane.size() <<"\n");
208 while (CurPlane.size() != ModuleSize) {
209 //SC_DEBUG(" Removing [" << i << "] Value=" << CurPlane.back() << "\n");
210 std::map<const Value *, unsigned>::iterator NI =
211 NodeMap.find(CurPlane.back());
212 assert(NI != NodeMap.end() && "Node not in nodemap?");
213 NodeMap.erase(NI); // Erase from nodemap
214 CurPlane.pop_back(); // Shrink plane
218 // We don't need this state anymore, free it up.
221 // Next, remove any type planes defined by the function...
222 while (NumModuleTypes != Table.size()) {
223 TypePlane &Plane = Table.back();
224 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
225 << Plane.size() << "\n");
226 while (Plane.size()) {
227 NodeMap.erase(NodeMap.find(Plane.back())); // Erase from nodemap
228 Plane.pop_back(); // Shrink plane
231 Table.pop_back(); // Nuke the plane, we don't like it.
234 SC_DEBUG("end purgeFunction!\n");
237 int SlotCalculator::getSlot(const Value *D) const {
238 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(D);
239 if (I == NodeMap.end()) return -1;
241 return (int)I->second;
245 int SlotCalculator::getOrCreateSlot(const Value *V) {
246 int SlotNo = getSlot(V); // Check to see if it's already in!
247 if (SlotNo != -1) return SlotNo;
249 if (!isa<GlobalValue>(V))
250 if (const Constant *C = dyn_cast<Constant>(V)) {
251 // This makes sure that if a constant has uses (for example an array of
252 // const ints), that they are inserted also.
254 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
259 return insertValue(V);
263 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
264 assert(D && "Can't insert a null value!");
265 assert(getSlot(D) == -1 && "Value is already in the table!");
267 // If this node does not contribute to a plane, or if the node has a
268 // name and we don't want names, then ignore the silly node... Note that types
269 // do need slot numbers so that we can keep track of where other values land.
271 if (!dontIgnore) // Don't ignore nonignorables!
272 if (D->getType() == Type::VoidTy || // Ignore void type nodes
273 (IgnoreNamedNodes && // Ignore named and constants
274 (D->hasName() || isa<Constant>(D)) && !isa<Type>(D))) {
275 SC_DEBUG("ignored value " << *D << "\n");
276 return -1; // We do need types unconditionally though
279 // If it's a type, make sure that all subtypes of the type are included...
280 if (const Type *TheTy = dyn_cast<Type>(D)) {
282 // Insert the current type before any subtypes. This is important because
283 // recursive types elements are inserted in a bottom up order. Changing
284 // this here can break things. For example:
286 // global { \2 * } { { \2 }* null }
288 int ResultSlot = doInsertValue(TheTy);
289 SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
292 // Loop over any contained types in the definition... in post
295 for (po_iterator<const Type*> I = po_begin(TheTy), E = po_end(TheTy);
298 const Type *SubTy = *I;
299 // If we haven't seen this sub type before, add it to our type table!
300 if (getSlot(SubTy) == -1) {
301 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
302 int Slot = doInsertValue(SubTy);
303 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
304 " slot=" << Slot << "\n");
311 // Okay, everything is happy, actually insert the silly value now...
312 return doInsertValue(D);
316 // doInsertValue - This is a small helper function to be called only
319 int SlotCalculator::doInsertValue(const Value *D) {
320 const Type *Typ = D->getType();
323 // Used for debugging DefSlot=-1 assertion...
324 //if (Typ == Type::TypeTy)
325 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
327 if (Typ->isDerivedType()) {
328 int ValSlot = getSlot(Typ);
329 if (ValSlot == -1) { // Have we already entered this type?
330 // Nope, this is the first we have seen the type, process it.
331 ValSlot = insertValue(Typ, true);
332 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
334 Ty = (unsigned)ValSlot;
336 Ty = Typ->getPrimitiveID();
339 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
340 Table.resize(Ty+1, TypePlane());
342 // If this is the first value to get inserted into the type plane, make sure
343 // to insert the implicit null value...
344 if (Table[Ty].empty() && Ty >= Type::FirstDerivedTyID && !IgnoreNamedNodes) {
345 Value *ZeroInitializer = Constant::getNullValue(Typ);
347 // If we are pushing zeroinit, it will be handled below.
348 if (D != ZeroInitializer) {
349 Table[Ty].push_back(ZeroInitializer);
350 NodeMap[ZeroInitializer] = 0;
354 // Insert node into table and NodeMap...
355 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
356 Table[Ty].push_back(D);
358 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
360 // G = Global, C = Constant, T = Type, F = Function, o = other
361 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
362 (isa<Type>(D) ? "T" : (isa<Function>(D) ? "F" : "o")))));
364 return (int)DestSlot;
367 } // End llvm namespace