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/DepthFirstIterator.h"
27 #include "Support/STLExtras.h"
31 #define SC_DEBUG(X) std::cerr << X
36 SlotCalculator::SlotCalculator(const Module *M, bool IgnoreNamed) {
37 IgnoreNamedNodes = IgnoreNamed;
40 // Preload table... Make sure that all of the primitive types are in the table
41 // and that their Primitive ID is equal to their slot #
43 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
44 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
45 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
48 if (M == 0) return; // Empty table...
52 SlotCalculator::SlotCalculator(const Function *M, bool IgnoreNamed) {
53 IgnoreNamedNodes = IgnoreNamed;
54 TheModule = M ? M->getParent() : 0;
56 // Preload table... Make sure that all of the primitive types are in the table
57 // and that their Primitive ID is equal to their slot #
59 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
60 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
61 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
64 if (TheModule == 0) return; // Empty table...
66 processModule(); // Process module level stuff
67 incorporateFunction(M); // Start out in incorporated state
71 // processModule - Process all of the module level function declarations and
72 // types that are available.
74 void SlotCalculator::processModule() {
75 SC_DEBUG("begin processModule!\n");
77 // Add all of the global variables to the value table...
79 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
83 // Scavenge the types out of the functions, then add the functions themselves
84 // to the value table...
86 for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
90 // Add all of the module level constants used as initializers
92 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
94 if (I->hasInitializer())
95 getOrCreateSlot(I->getInitializer());
97 // Insert constants that are named at module level into the slot pool so that
98 // the module symbol table can refer to them...
100 if (!IgnoreNamedNodes) {
101 SC_DEBUG("Inserting SymbolTable values:\n");
102 processSymbolTable(&TheModule->getSymbolTable());
105 SC_DEBUG("end processModule!\n");
108 // processSymbolTable - Insert all of the values in the specified symbol table
109 // into the values table...
111 void SlotCalculator::processSymbolTable(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 getOrCreateSlot(TI->second);
118 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
119 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
120 for (SymbolTable::type_const_iterator TI = I->second.begin(),
121 TE = I->second.end(); TI != TE; ++TI)
122 if (isa<Constant>(TI->second))
123 getOrCreateSlot(TI->second);
127 void SlotCalculator::incorporateFunction(const Function *F) {
128 assert(ModuleLevel.size() == 0 && "Module already incorporated!");
130 SC_DEBUG("begin processFunction!\n");
132 // Save the Table state before we process the function...
133 for (unsigned i = 0; i < Table.size(); ++i)
134 ModuleLevel.push_back(Table[i].size());
136 SC_DEBUG("Inserting function arguments\n");
138 // Iterate over function arguments, adding them to the value table...
139 for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
142 // Iterate over all of the instructions in the function, looking for constant
143 // values that are referenced. Add these to the value pools before any
144 // nonconstant values. This will be turned into the constant pool for the
147 if (!IgnoreNamedNodes) { // Assembly writer does not need this!
148 SC_DEBUG("Inserting function constants:\n";
149 for (constant_iterator I = constant_begin(F), E = constant_end(F);
151 std::cerr << " " << *I->getType() << " " << *I << "\n";
154 // Emit all of the constants that are being used by the instructions in the
156 for_each(constant_begin(F), constant_end(F),
157 bind_obj(this, &SlotCalculator::getOrCreateSlot));
159 // If there is a symbol table, it is possible that the user has names for
160 // constants that are not being used. In this case, we will have problems
161 // if we don't emit the constants now, because otherwise we will get
162 // symboltable references to constants not in the output. Scan for these
165 processSymbolTableConstants(&F->getSymbolTable());
168 SC_DEBUG("Inserting Labels:\n");
170 // Iterate over basic blocks, adding them to the value table...
171 for (Function::const_iterator I = F->begin(), E = F->end(); I != E; ++I)
174 SC_DEBUG("Inserting Instructions:\n");
176 // Add all of the instructions to the type planes...
177 for_each(inst_begin(F), inst_end(F),
178 bind_obj(this, &SlotCalculator::getOrCreateSlot));
180 if (!IgnoreNamedNodes) {
181 SC_DEBUG("Inserting SymbolTable values:\n");
182 processSymbolTable(&F->getSymbolTable());
185 SC_DEBUG("end processFunction!\n");
188 void SlotCalculator::purgeFunction() {
189 assert(ModuleLevel.size() != 0 && "Module not incorporated!");
190 unsigned NumModuleTypes = ModuleLevel.size();
192 SC_DEBUG("begin purgeFunction!\n");
194 // First, remove values from existing type planes
195 for (unsigned i = 0; i < NumModuleTypes; ++i) {
196 unsigned ModuleSize = ModuleLevel[i]; // Size of plane before function came
197 TypePlane &CurPlane = Table[i];
198 //SC_DEBUG("Processing Plane " <<i<< " of size " << CurPlane.size() <<"\n");
200 while (CurPlane.size() != ModuleSize) {
201 //SC_DEBUG(" Removing [" << i << "] Value=" << CurPlane.back() << "\n");
202 std::map<const Value *, unsigned>::iterator NI =
203 NodeMap.find(CurPlane.back());
204 assert(NI != NodeMap.end() && "Node not in nodemap?");
205 NodeMap.erase(NI); // Erase from nodemap
206 CurPlane.pop_back(); // Shrink plane
210 // We don't need this state anymore, free it up.
213 // Next, remove any type planes defined by the function...
214 while (NumModuleTypes != Table.size()) {
215 TypePlane &Plane = Table.back();
216 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
217 << Plane.size() << "\n");
218 while (Plane.size()) {
219 NodeMap.erase(NodeMap.find(Plane.back())); // Erase from nodemap
220 Plane.pop_back(); // Shrink plane
223 Table.pop_back(); // Nuke the plane, we don't like it.
226 SC_DEBUG("end purgeFunction!\n");
229 int SlotCalculator::getSlot(const Value *D) const {
230 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(D);
231 if (I == NodeMap.end()) return -1;
233 return (int)I->second;
237 int SlotCalculator::getOrCreateSlot(const Value *V) {
238 int SlotNo = getSlot(V); // Check to see if it's already in!
239 if (SlotNo != -1) return SlotNo;
241 if (!isa<GlobalValue>(V))
242 if (const Constant *C = dyn_cast<Constant>(V)) {
243 // This makes sure that if a constant has uses (for example an array of
244 // const ints), that they are inserted also.
246 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
251 return insertValue(V);
255 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
256 assert(D && "Can't insert a null value!");
257 assert(getSlot(D) == -1 && "Value is already in the table!");
259 // If this node does not contribute to a plane, or if the node has a
260 // name and we don't want names, then ignore the silly node... Note that types
261 // do need slot numbers so that we can keep track of where other values land.
263 if (!dontIgnore) // Don't ignore nonignorables!
264 if (D->getType() == Type::VoidTy || // Ignore void type nodes
265 (IgnoreNamedNodes && // Ignore named and constants
266 (D->hasName() || isa<Constant>(D)) && !isa<Type>(D))) {
267 SC_DEBUG("ignored value " << *D << "\n");
268 return -1; // We do need types unconditionally though
271 // If it's a type, make sure that all subtypes of the type are included...
272 if (const Type *TheTy = dyn_cast<Type>(D)) {
274 // Insert the current type before any subtypes. This is important because
275 // recursive types elements are inserted in a bottom up order. Changing
276 // this here can break things. For example:
278 // global { \2 * } { { \2 }* null }
280 int ResultSlot = doInsertValue(TheTy);
281 SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
284 // Loop over any contained types in the definition... in depth first order.
286 for (df_iterator<const Type*> I = df_begin(TheTy), E = df_end(TheTy);
289 // If we haven't seen this sub type before, add it to our type table!
290 const Type *SubTy = *I;
291 if (getSlot(SubTy) == -1) {
292 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
293 int Slot = doInsertValue(SubTy);
294 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
295 " slot=" << Slot << "\n");
301 // Okay, everything is happy, actually insert the silly value now...
302 return doInsertValue(D);
306 // doInsertValue - This is a small helper function to be called only
309 int SlotCalculator::doInsertValue(const Value *D) {
310 const Type *Typ = D->getType();
313 // Used for debugging DefSlot=-1 assertion...
314 //if (Typ == Type::TypeTy)
315 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
317 if (Typ->isDerivedType()) {
318 int ValSlot = getSlot(Typ);
319 if (ValSlot == -1) { // Have we already entered this type?
320 // Nope, this is the first we have seen the type, process it.
321 ValSlot = insertValue(Typ, true);
322 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
324 Ty = (unsigned)ValSlot;
326 Ty = Typ->getPrimitiveID();
329 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
330 Table.resize(Ty+1, TypePlane());
332 // If this is the first value to get inserted into the type plane, make sure
333 // to insert the implicit null value...
334 if (Table[Ty].empty() && Ty >= Type::FirstDerivedTyID && !IgnoreNamedNodes) {
335 Value *ZeroInitializer = Constant::getNullValue(Typ);
337 // If we are pushing zeroinit, it will be handled below.
338 if (D != ZeroInitializer) {
339 Table[Ty].push_back(ZeroInitializer);
340 NodeMap[ZeroInitializer] = 0;
344 // Insert node into table and NodeMap...
345 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
346 Table[Ty].push_back(D);
348 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
350 // G = Global, C = Constant, T = Type, F = Function, o = other
351 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
352 (isa<Type>(D) ? "T" : (isa<Function>(D) ? "F" : "o")))));
354 return (int)DestSlot;