1 //===-- ValueEnumerator.cpp - Number values and types for bitcode writer --===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the ValueEnumerator class.
12 //===----------------------------------------------------------------------===//
14 #include "ValueEnumerator.h"
15 #include "llvm/Constants.h"
16 #include "llvm/DerivedTypes.h"
17 #include "llvm/Metadata.h"
18 #include "llvm/Module.h"
19 #include "llvm/TypeSymbolTable.h"
20 #include "llvm/ValueSymbolTable.h"
21 #include "llvm/Instructions.h"
25 static bool isSingleValueType(const std::pair<const llvm::Type*,
27 return P.first->isSingleValueType();
30 static bool isIntegerValue(const std::pair<const Value*, unsigned> &V) {
31 return isa<IntegerType>(V.first->getType());
34 static bool CompareByFrequency(const std::pair<const llvm::Type*,
36 const std::pair<const llvm::Type*,
38 return P1.second > P2.second;
41 /// ValueEnumerator - Enumerate module-level information.
42 ValueEnumerator::ValueEnumerator(const Module *M) {
45 // Enumerate the global variables.
46 for (Module::const_global_iterator I = M->global_begin(),
47 E = M->global_end(); I != E; ++I)
50 // Enumerate the functions.
51 for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
53 EnumerateAttributes(cast<Function>(I)->getAttributes());
56 // Enumerate the aliases.
57 for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
61 // Remember what is the cutoff between globalvalue's and other constants.
62 unsigned FirstConstant = Values.size();
64 // Enumerate the global variable initializers.
65 for (Module::const_global_iterator I = M->global_begin(),
66 E = M->global_end(); I != E; ++I)
67 if (I->hasInitializer())
68 EnumerateValue(I->getInitializer());
70 // Enumerate the aliasees.
71 for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
73 EnumerateValue(I->getAliasee());
75 // Enumerate types used by the type symbol table.
76 EnumerateTypeSymbolTable(M->getTypeSymbolTable());
78 // Insert constants that are named at module level into the slot pool so that
79 // the module symbol table can refer to them...
80 EnumerateValueSymbolTable(M->getValueSymbolTable());
82 // Enumerate types used by function bodies and argument lists.
83 for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
85 for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
87 EnumerateType(I->getType());
89 MetadataContext &TheMetadata = F->getContext().getMetadata();
90 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
91 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E;++I){
92 for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
94 EnumerateOperandType(*OI);
95 EnumerateType(I->getType());
96 if (const CallInst *CI = dyn_cast<CallInst>(I))
97 EnumerateAttributes(CI->getAttributes());
98 else if (const InvokeInst *II = dyn_cast<InvokeInst>(I))
99 EnumerateAttributes(II->getAttributes());
101 // Enumerate metadata attached with this instruction.
102 const MetadataContext::MDMapTy *MDs = TheMetadata.getMDs(I);
104 for (MetadataContext::MDMapTy::const_iterator MI = MDs->begin(),
105 ME = MDs->end(); MI != ME; ++MI)
106 EnumerateMetadata(MI->second);
110 // Optimize constant ordering.
111 OptimizeConstants(FirstConstant, Values.size());
113 // Sort the type table by frequency so that most commonly used types are early
114 // in the table (have low bit-width).
115 std::stable_sort(Types.begin(), Types.end(), CompareByFrequency);
117 // Partition the Type ID's so that the single-value types occur before the
118 // aggregate types. This allows the aggregate types to be dropped from the
119 // type table after parsing the global variable initializers.
120 std::partition(Types.begin(), Types.end(), isSingleValueType);
122 // Now that we rearranged the type table, rebuild TypeMap.
123 for (unsigned i = 0, e = Types.size(); i != e; ++i)
124 TypeMap[Types[i].first] = i+1;
127 unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
128 InstructionMapType::const_iterator I = InstructionMap.find(Inst);
129 assert (I != InstructionMap.end() && "Instruction is not mapped!");
133 void ValueEnumerator::setInstructionID(const Instruction *I) {
134 InstructionMap[I] = InstructionCount++;
137 unsigned ValueEnumerator::getValueID(const Value *V) const {
138 if (isa<MetadataBase>(V)) {
139 ValueMapType::const_iterator I = MDValueMap.find(V);
140 assert(I != MDValueMap.end() && "Value not in slotcalculator!");
144 ValueMapType::const_iterator I = ValueMap.find(V);
145 assert(I != ValueMap.end() && "Value not in slotcalculator!");
149 // Optimize constant ordering.
151 struct CstSortPredicate {
153 explicit CstSortPredicate(ValueEnumerator &ve) : VE(ve) {}
154 bool operator()(const std::pair<const Value*, unsigned> &LHS,
155 const std::pair<const Value*, unsigned> &RHS) {
157 if (LHS.first->getType() != RHS.first->getType())
158 return VE.getTypeID(LHS.first->getType()) <
159 VE.getTypeID(RHS.first->getType());
160 // Then by frequency.
161 return LHS.second > RHS.second;
166 /// OptimizeConstants - Reorder constant pool for denser encoding.
167 void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
168 if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
170 CstSortPredicate P(*this);
171 std::stable_sort(Values.begin()+CstStart, Values.begin()+CstEnd, P);
173 // Ensure that integer constants are at the start of the constant pool. This
174 // is important so that GEP structure indices come before gep constant exprs.
175 std::partition(Values.begin()+CstStart, Values.begin()+CstEnd,
178 // Rebuild the modified portion of ValueMap.
179 for (; CstStart != CstEnd; ++CstStart)
180 ValueMap[Values[CstStart].first] = CstStart+1;
184 /// EnumerateTypeSymbolTable - Insert all of the types in the specified symbol
186 void ValueEnumerator::EnumerateTypeSymbolTable(const TypeSymbolTable &TST) {
187 for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
189 EnumerateType(TI->second);
192 /// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
193 /// table into the values table.
194 void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
195 for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
197 EnumerateValue(VI->getValue());
200 void ValueEnumerator::EnumerateMetadata(const MetadataBase *MD) {
201 // Check to see if it's already in!
202 unsigned &MDValueID = MDValueMap[MD];
204 // Increment use count.
205 MDValues[MDValueID-1].second++;
209 // Enumerate the type of this value.
210 EnumerateType(MD->getType());
212 if (const MDNode *N = dyn_cast<MDNode>(MD)) {
213 MDValues.push_back(std::make_pair(MD, 1U));
214 MDValueMap[MD] = MDValues.size();
215 MDValueID = MDValues.size();
216 for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
217 if (Value *V = N->getElement(i))
220 EnumerateType(Type::getVoidTy(MD->getContext()));
223 } else if (const NamedMDNode *N = dyn_cast<NamedMDNode>(MD)) {
224 for(NamedMDNode::const_elem_iterator I = N->elem_begin(),
225 E = N->elem_end(); I != E; ++I) {
226 MetadataBase *M = *I;
229 MDValues.push_back(std::make_pair(MD, 1U));
230 MDValueMap[MD] = Values.size();
235 MDValues.push_back(std::make_pair(MD, 1U));
236 MDValueID = MDValues.size();
239 void ValueEnumerator::EnumerateValue(const Value *V) {
240 assert(V->getType() != Type::getVoidTy(V->getContext()) &&
241 "Can't insert void values!");
242 if (const MetadataBase *MB = dyn_cast<MetadataBase>(V))
243 return EnumerateMetadata(MB);
245 // Check to see if it's already in!
246 unsigned &ValueID = ValueMap[V];
248 // Increment use count.
249 Values[ValueID-1].second++;
253 // Enumerate the type of this value.
254 EnumerateType(V->getType());
256 if (const Constant *C = dyn_cast<Constant>(V)) {
257 if (isa<GlobalValue>(C)) {
258 // Initializers for globals are handled explicitly elsewhere.
259 } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
260 // Do not enumerate the initializers for an array of simple characters.
261 // The initializers just polute the value table, and we emit the strings
263 } else if (C->getNumOperands()) {
264 // If a constant has operands, enumerate them. This makes sure that if a
265 // constant has uses (for example an array of const ints), that they are
268 // We prefer to enumerate them with values before we enumerate the user
269 // itself. This makes it more likely that we can avoid forward references
270 // in the reader. We know that there can be no cycles in the constants
271 // graph that don't go through a global variable.
272 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
276 // Finally, add the value. Doing this could make the ValueID reference be
277 // dangling, don't reuse it.
278 Values.push_back(std::make_pair(V, 1U));
279 ValueMap[V] = Values.size();
285 Values.push_back(std::make_pair(V, 1U));
286 ValueID = Values.size();
290 void ValueEnumerator::EnumerateType(const Type *Ty) {
291 unsigned &TypeID = TypeMap[Ty];
294 // If we've already seen this type, just increase its occurrence count.
295 Types[TypeID-1].second++;
299 // First time we saw this type, add it.
300 Types.push_back(std::make_pair(Ty, 1U));
301 TypeID = Types.size();
303 // Enumerate subtypes.
304 for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
309 // Enumerate the types for the specified value. If the value is a constant,
310 // walk through it, enumerating the types of the constant.
311 void ValueEnumerator::EnumerateOperandType(const Value *V) {
312 EnumerateType(V->getType());
313 if (const Constant *C = dyn_cast<Constant>(V)) {
314 // If this constant is already enumerated, ignore it, we know its type must
316 if (ValueMap.count(V)) return;
318 // This constant may have operands, make sure to enumerate the types in
320 for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
321 EnumerateOperandType(C->getOperand(i));
323 if (const MDNode *N = dyn_cast<MDNode>(V)) {
324 for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
325 Value *Elem = N->getElement(i);
327 EnumerateOperandType(Elem);
330 } else if (isa<MDString>(V) || isa<MDNode>(V))
334 void ValueEnumerator::EnumerateAttributes(const AttrListPtr &PAL) {
335 if (PAL.isEmpty()) return; // null is always 0.
337 unsigned &Entry = AttributeMap[PAL.getRawPointer()];
339 // Never saw this before, add it.
340 Attributes.push_back(PAL);
341 Entry = Attributes.size();
346 void ValueEnumerator::incorporateFunction(const Function &F) {
347 NumModuleValues = Values.size();
349 // Adding function arguments to the value table.
350 for(Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end();
354 FirstFuncConstantID = Values.size();
356 // Add all function-level constants to the value table.
357 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
358 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I)
359 for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
361 if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
365 BasicBlocks.push_back(BB);
366 ValueMap[BB] = BasicBlocks.size();
369 // Optimize the constant layout.
370 OptimizeConstants(FirstFuncConstantID, Values.size());
372 // Add the function's parameter attributes so they are available for use in
373 // the function's instruction.
374 EnumerateAttributes(F.getAttributes());
376 FirstInstID = Values.size();
378 // Add all of the instructions.
379 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
380 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
381 if (I->getType() != Type::getVoidTy(F.getContext()))
387 void ValueEnumerator::purgeFunction() {
388 /// Remove purged values from the ValueMap.
389 for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
390 ValueMap.erase(Values[i].first);
391 for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
392 ValueMap.erase(BasicBlocks[i]);
394 Values.resize(NumModuleValues);