1 //===-- SlotCalculator.cpp - Calculate what slots values land in ----------===//
3 // This file implements a useful analysis step to figure out what numbered
4 // slots values in a program will land in (keeping track of per plane
5 // information as required.
7 // This is used primarily for when writing a file to disk, either in bytecode
10 //===----------------------------------------------------------------------===//
12 #include "llvm/SlotCalculator.h"
13 #include "llvm/Analysis/ConstantsScanner.h"
14 #include "llvm/Module.h"
15 #include "llvm/iOther.h"
16 #include "llvm/Constant.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/SymbolTable.h"
19 #include "Support/DepthFirstIterator.h"
20 #include "Support/STLExtras.h"
24 #define SC_DEBUG(X) std::cerr << X
29 SlotCalculator::SlotCalculator(const Module *M, bool IgnoreNamed) {
30 IgnoreNamedNodes = IgnoreNamed;
33 // Preload table... Make sure that all of the primitive types are in the table
34 // and that their Primitive ID is equal to their slot #
36 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
37 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
38 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
41 if (M == 0) return; // Empty table...
45 SlotCalculator::SlotCalculator(const Function *M, bool IgnoreNamed) {
46 IgnoreNamedNodes = IgnoreNamed;
47 TheModule = M ? M->getParent() : 0;
49 // Preload table... Make sure that all of the primitive types are in the table
50 // and that their Primitive ID is equal to their slot #
52 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
53 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
54 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
57 if (TheModule == 0) return; // Empty table...
59 processModule(); // Process module level stuff
60 incorporateFunction(M); // Start out in incorporated state
64 // processModule - Process all of the module level function declarations and
65 // types that are available.
67 void SlotCalculator::processModule() {
68 SC_DEBUG("begin processModule!\n");
70 // Add all of the global variables to the value table...
72 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
76 // Scavenge the types out of the functions, then add the functions themselves
77 // to the value table...
79 for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
83 // Add all of the module level constants used as initializers
85 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
87 if (I->hasInitializer())
88 getOrCreateSlot(I->getInitializer());
90 // Insert constants that are named at module level into the slot pool so that
91 // the module symbol table can refer to them...
93 if (!IgnoreNamedNodes) {
94 SC_DEBUG("Inserting SymbolTable values:\n");
95 processSymbolTable(&TheModule->getSymbolTable());
98 SC_DEBUG("end processModule!\n");
101 // processSymbolTable - Insert all of the values in the specified symbol table
102 // into the values table...
104 void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
105 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
106 for (SymbolTable::type_const_iterator TI = I->second.begin(),
107 TE = I->second.end(); TI != TE; ++TI)
108 getOrCreateSlot(TI->second);
111 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
112 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
113 for (SymbolTable::type_const_iterator TI = I->second.begin(),
114 TE = I->second.end(); TI != TE; ++TI)
115 if (isa<Constant>(TI->second))
116 getOrCreateSlot(TI->second);
120 void SlotCalculator::incorporateFunction(const Function *M) {
121 assert(ModuleLevel.size() == 0 && "Module already incorporated!");
123 SC_DEBUG("begin processFunction!\n");
125 // Save the Table state before we process the function...
126 for (unsigned i = 0; i < Table.size(); ++i)
127 ModuleLevel.push_back(Table[i].size());
129 SC_DEBUG("Inserting function arguments\n");
131 // Iterate over function arguments, adding them to the value table...
132 for(Function::const_aiterator I = M->abegin(), E = M->aend(); I != E; ++I)
135 // Iterate over all of the instructions in the function, looking for constant
136 // values that are referenced. Add these to the value pools before any
137 // nonconstant values. This will be turned into the constant pool for the
140 if (!IgnoreNamedNodes) { // Assembly writer does not need this!
141 SC_DEBUG("Inserting function constants:\n";
142 for (constant_iterator I = constant_begin(M), E = constant_end(M);
144 std::cerr << " " << *I->getType() << " " << *I << "\n";
147 // Emit all of the constants that are being used by the instructions in the
149 for_each(constant_begin(M), constant_end(M),
150 bind_obj(this, &SlotCalculator::getOrCreateSlot));
152 // If there is a symbol table, it is possible that the user has names for
153 // constants that are not being used. In this case, we will have problems
154 // if we don't emit the constants now, because otherwise we will get
155 // symboltable references to constants not in the output. Scan for these
158 processSymbolTableConstants(&M->getSymbolTable());
161 SC_DEBUG("Inserting Labels:\n");
163 // Iterate over basic blocks, adding them to the value table...
164 for (Function::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
167 SC_DEBUG("Inserting Instructions:\n");
169 // Add all of the instructions to the type planes...
170 for_each(inst_begin(M), inst_end(M),
171 bind_obj(this, &SlotCalculator::getOrCreateSlot));
173 if (!IgnoreNamedNodes) {
174 SC_DEBUG("Inserting SymbolTable values:\n");
175 processSymbolTable(&M->getSymbolTable());
178 SC_DEBUG("end processFunction!\n");
181 void SlotCalculator::purgeFunction() {
182 assert(ModuleLevel.size() != 0 && "Module not incorporated!");
183 unsigned NumModuleTypes = ModuleLevel.size();
185 SC_DEBUG("begin purgeFunction!\n");
187 // First, remove values from existing type planes
188 for (unsigned i = 0; i < NumModuleTypes; ++i) {
189 unsigned ModuleSize = ModuleLevel[i]; // Size of plane before function came
190 TypePlane &CurPlane = Table[i];
191 //SC_DEBUG("Processing Plane " <<i<< " of size " << CurPlane.size() <<"\n");
193 while (CurPlane.size() != ModuleSize) {
194 //SC_DEBUG(" Removing [" << i << "] Value=" << CurPlane.back() << "\n");
195 std::map<const Value *, unsigned>::iterator NI =
196 NodeMap.find(CurPlane.back());
197 assert(NI != NodeMap.end() && "Node not in nodemap?");
198 NodeMap.erase(NI); // Erase from nodemap
199 CurPlane.pop_back(); // Shrink plane
203 // We don't need this state anymore, free it up.
206 // Next, remove any type planes defined by the function...
207 while (NumModuleTypes != Table.size()) {
208 TypePlane &Plane = Table.back();
209 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
210 << Plane.size() << "\n");
211 while (Plane.size()) {
212 NodeMap.erase(NodeMap.find(Plane.back())); // Erase from nodemap
213 Plane.pop_back(); // Shrink plane
216 Table.pop_back(); // Nuke the plane, we don't like it.
219 SC_DEBUG("end purgeFunction!\n");
222 int SlotCalculator::getSlot(const Value *D) const {
223 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(D);
224 if (I == NodeMap.end()) return -1;
226 return (int)I->second;
230 int SlotCalculator::getOrCreateSlot(const Value *V) {
231 int SlotNo = getSlot(V); // Check to see if it's already in!
232 if (SlotNo != -1) return SlotNo;
234 if (!isa<GlobalValue>(V))
235 if (const Constant *C = dyn_cast<Constant>(V)) {
236 // This makes sure that if a constant has uses (for example an array of
237 // const ints), that they are inserted also.
239 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
244 return insertValue(V);
248 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
249 assert(D && "Can't insert a null value!");
250 assert(getSlot(D) == -1 && "Value is already in the table!");
252 // If this node does not contribute to a plane, or if the node has a
253 // name and we don't want names, then ignore the silly node... Note that types
254 // do need slot numbers so that we can keep track of where other values land.
256 if (!dontIgnore) // Don't ignore nonignorables!
257 if (D->getType() == Type::VoidTy || // Ignore void type nodes
258 (IgnoreNamedNodes && // Ignore named and constants
259 (D->hasName() || isa<Constant>(D)) && !isa<Type>(D))) {
260 SC_DEBUG("ignored value " << *D << "\n");
261 return -1; // We do need types unconditionally though
264 // If it's a type, make sure that all subtypes of the type are included...
265 if (const Type *TheTy = dyn_cast<Type>(D)) {
267 // Insert the current type before any subtypes. This is important because
268 // recursive types elements are inserted in a bottom up order. Changing
269 // this here can break things. For example:
271 // global { \2 * } { { \2 }* null }
273 int ResultSlot = doInsertValue(TheTy);
274 SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
277 // Loop over any contained types in the definition... in depth first order.
279 for (df_iterator<const Type*> I = df_begin(TheTy), E = df_end(TheTy);
282 // If we haven't seen this sub type before, add it to our type table!
283 const Type *SubTy = *I;
284 if (getSlot(SubTy) == -1) {
285 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
286 int Slot = doInsertValue(SubTy);
287 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
288 " slot=" << Slot << "\n");
294 // Okay, everything is happy, actually insert the silly value now...
295 return doInsertValue(D);
299 // doInsertValue - This is a small helper function to be called only
302 int SlotCalculator::doInsertValue(const Value *D) {
303 const Type *Typ = D->getType();
306 // Used for debugging DefSlot=-1 assertion...
307 //if (Typ == Type::TypeTy)
308 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
310 if (Typ->isDerivedType()) {
311 int ValSlot = getSlot(Typ);
312 if (ValSlot == -1) { // Have we already entered this type?
313 // Nope, this is the first we have seen the type, process it.
314 ValSlot = insertValue(Typ, true);
315 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
317 Ty = (unsigned)ValSlot;
319 Ty = Typ->getPrimitiveID();
322 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
323 Table.resize(Ty+1, TypePlane());
325 // If this is the first value to get inserted into the type plane, make sure
326 // to insert the implicit null value...
327 if (Table[Ty].empty() && Ty >= Type::FirstDerivedTyID && !IgnoreNamedNodes) {
328 Value *ZeroInitializer = Constant::getNullValue(Typ);
330 // If we are pushing zeroinit, it will be handled below.
331 if (D != ZeroInitializer) {
332 Table[Ty].push_back(ZeroInitializer);
333 NodeMap[ZeroInitializer] = 0;
337 // Insert node into table and NodeMap...
338 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
339 Table[Ty].push_back(D);
341 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
343 // G = Global, C = Constant, T = Type, F = Function, o = other
344 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
345 (isa<Type>(D) ? "T" : (isa<Function>(D) ? "F" : "o")))));
347 return (int)DestSlot;