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 slots
11 // values in a program will land in (keeping track of per plane information).
13 // This is used when writing a file to disk, either in bytecode or assembly.
15 //===----------------------------------------------------------------------===//
17 #include "llvm/Analysis/SlotCalculator.h"
18 #include "llvm/Constants.h"
19 #include "llvm/DerivedTypes.h"
20 #include "llvm/iOther.h"
21 #include "llvm/Module.h"
22 #include "llvm/SymbolTable.h"
23 #include "llvm/Analysis/ConstantsScanner.h"
24 #include "Support/PostOrderIterator.h"
25 #include "Support/STLExtras.h"
30 #define SC_DEBUG(X) std::cerr << X
35 SlotCalculator::SlotCalculator(const Module *M, bool buildBytecodeInfo) {
36 BuildBytecodeInfo = buildBytecodeInfo;
37 ModuleContainsAllFunctionConstants = false;
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 SC_DEBUG("Inserting primitive types:\n");
44 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
45 assert(Type::getPrimitiveType((Type::PrimitiveID)i));
46 insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
49 if (M == 0) return; // Empty table...
53 SlotCalculator::SlotCalculator(const Function *M, bool buildBytecodeInfo) {
54 BuildBytecodeInfo = buildBytecodeInfo;
55 ModuleContainsAllFunctionConstants = false;
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
73 unsigned SlotCalculator::getGlobalSlot(const Value *V) const {
74 assert(!CompactionTable.empty() &&
75 "This method can only be used when compaction is enabled!");
76 if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
78 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
79 assert(I != NodeMap.end() && "Didn't find global slot entry!");
83 SlotCalculator::TypePlane &SlotCalculator::getPlane(unsigned Plane) {
84 unsigned PIdx = Plane;
85 if (CompactionTable.empty()) { // No compaction table active?
87 } else if (!CompactionTable[Plane].empty()) { // Compaction table active.
88 assert(Plane < CompactionTable.size());
89 return CompactionTable[Plane];
91 // Final case: compaction table active, but this plane is not
92 // compactified. If the type plane is compactified, unmap back to the
93 // global type plane corresponding to "Plane".
94 if (!CompactionTable[Type::TypeTyID].empty()) {
95 const Type *Ty = cast<Type>(CompactionTable[Type::TypeTyID][Plane]);
96 std::map<const Value*, unsigned>::iterator It = NodeMap.find(Ty);
97 assert(It != NodeMap.end() && "Type not in global constant map?");
102 // Okay we are just returning an entry out of the main Table. Make sure the
103 // plane exists and return it.
104 if (PIdx >= Table.size())
105 Table.resize(PIdx+1);
110 // processModule - Process all of the module level function declarations and
111 // types that are available.
113 void SlotCalculator::processModule() {
114 SC_DEBUG("begin processModule!\n");
116 // Add all of the global variables to the value table...
118 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
122 // Scavenge the types out of the functions, then add the functions themselves
123 // to the value table...
125 for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
129 // Add all of the module level constants used as initializers
131 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
133 if (I->hasInitializer())
134 getOrCreateSlot(I->getInitializer());
136 // Now that all global constants have been added, rearrange constant planes
137 // that contain constant strings so that the strings occur at the start of the
138 // plane, not somewhere in the middle.
140 if (BuildBytecodeInfo) {
141 TypePlane &Types = Table[Type::TypeTyID];
142 for (unsigned plane = 0, e = Table.size(); plane != e; ++plane) {
143 if (const ArrayType *AT = dyn_cast<ArrayType>(Types[plane]))
144 if (AT->getElementType() == Type::SByteTy ||
145 AT->getElementType() == Type::UByteTy) {
146 TypePlane &Plane = Table[plane];
147 unsigned FirstNonStringID = 0;
148 for (unsigned i = 0, e = Plane.size(); i != e; ++i)
149 if (cast<ConstantArray>(Plane[i])->isString()) {
150 // Check to see if we have to shuffle this string around. If not,
151 // don't do anything.
152 if (i != FirstNonStringID) {
153 // Swap the plane entries....
154 std::swap(Plane[i], Plane[FirstNonStringID]);
156 // Keep the NodeMap up to date.
157 NodeMap[Plane[i]] = i;
158 NodeMap[Plane[FirstNonStringID]] = FirstNonStringID;
166 // If we are emitting a bytecode file, scan all of the functions for their
167 // constants, which allows us to emit more compact modules. This is optional,
168 // and is just used to compactify the constants used by different functions
171 // This functionality is completely optional for the bytecode writer, but
172 // tends to produce smaller bytecode files. This should not be used in the
173 // future by clients that want to, for example, build and emit functions on
174 // the fly. For now, however, it is unconditionally enabled when building
175 // bytecode information.
177 if (BuildBytecodeInfo) {
178 ModuleContainsAllFunctionConstants = true;
180 SC_DEBUG("Inserting function constants:\n");
181 for (Module::const_iterator F = TheModule->begin(), E = TheModule->end();
183 for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I){
184 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
185 if (isa<Constant>(I->getOperand(op)))
186 getOrCreateSlot(I->getOperand(op));
187 getOrCreateSlot(I->getType());
188 if (const VANextInst *VAN = dyn_cast<VANextInst>(*I))
189 getOrCreateSlot(VAN->getArgType());
191 processSymbolTableConstants(&F->getSymbolTable());
195 // Insert constants that are named at module level into the slot pool so that
196 // the module symbol table can refer to them...
198 if (BuildBytecodeInfo) {
199 SC_DEBUG("Inserting SymbolTable values:\n");
200 processSymbolTable(&TheModule->getSymbolTable());
203 // Now that we have collected together all of the information relevant to the
204 // module, compactify the type table if it is particularly big and outputting
205 // a bytecode file. The basic problem we run into is that some programs have
206 // a large number of types, which causes the type field to overflow its size,
207 // which causes instructions to explode in size (particularly call
208 // instructions). To avoid this behavior, we "sort" the type table so that
209 // all non-value types are pushed to the end of the type table, giving nice
210 // low numbers to the types that can be used by instructions, thus reducing
211 // the amount of explodage we suffer.
212 if (BuildBytecodeInfo && Table[Type::TypeTyID].size() >= 64) {
213 // Scan through the type table moving value types to the start of the table.
214 TypePlane *Types = &Table[Type::TypeTyID];
215 unsigned FirstNonValueTypeID = 0;
216 for (unsigned i = 0, e = Types->size(); i != e; ++i)
217 if (cast<Type>((*Types)[i])->isFirstClassType() ||
218 cast<Type>((*Types)[i])->isPrimitiveType()) {
219 // Check to see if we have to shuffle this type around. If not, don't
221 if (i != FirstNonValueTypeID) {
222 assert(i != Type::TypeTyID && FirstNonValueTypeID != Type::TypeTyID &&
223 "Cannot move around the type plane!");
225 // Swap the type ID's.
226 std::swap((*Types)[i], (*Types)[FirstNonValueTypeID]);
228 // Keep the NodeMap up to date.
229 NodeMap[(*Types)[i]] = i;
230 NodeMap[(*Types)[FirstNonValueTypeID]] = FirstNonValueTypeID;
232 // When we move a type, make sure to move its value plane as needed.
233 if (Table.size() > FirstNonValueTypeID) {
234 if (Table.size() <= i) Table.resize(i+1);
235 std::swap(Table[i], Table[FirstNonValueTypeID]);
236 Types = &Table[Type::TypeTyID];
239 ++FirstNonValueTypeID;
243 SC_DEBUG("end processModule!\n");
246 // processSymbolTable - Insert all of the values in the specified symbol table
247 // into the values table...
249 void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
250 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
251 for (SymbolTable::type_const_iterator TI = I->second.begin(),
252 TE = I->second.end(); TI != TE; ++TI)
253 getOrCreateSlot(TI->second);
256 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
257 for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
258 for (SymbolTable::type_const_iterator TI = I->second.begin(),
259 TE = I->second.end(); TI != TE; ++TI)
260 if (isa<Constant>(TI->second) || isa<Type>(TI->second))
261 getOrCreateSlot(TI->second);
265 void SlotCalculator::incorporateFunction(const Function *F) {
266 assert(ModuleLevel.size() == 0 && "Module already incorporated!");
268 SC_DEBUG("begin processFunction!\n");
270 // If we emitted all of the function constants, build a compaction table.
271 if (BuildBytecodeInfo && ModuleContainsAllFunctionConstants)
272 buildCompactionTable(F);
274 // Update the ModuleLevel entries to be accurate.
275 ModuleLevel.resize(getNumPlanes());
276 for (unsigned i = 0, e = getNumPlanes(); i != e; ++i)
277 ModuleLevel[i] = getPlane(i).size();
279 // Iterate over function arguments, adding them to the value table...
280 for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
283 if (BuildBytecodeInfo && // Assembly writer does not need this!
284 !ModuleContainsAllFunctionConstants) {
285 // Iterate over all of the instructions in the function, looking for
286 // constant values that are referenced. Add these to the value pools
287 // before any nonconstant values. This will be turned into the constant
288 // pool for the bytecode writer.
291 // Emit all of the constants that are being used by the instructions in
293 for_each(constant_begin(F), constant_end(F),
294 bind_obj(this, &SlotCalculator::getOrCreateSlot));
296 // If there is a symbol table, it is possible that the user has names for
297 // constants that are not being used. In this case, we will have problems
298 // if we don't emit the constants now, because otherwise we will get
299 // symbol table references to constants not in the output. Scan for these
302 processSymbolTableConstants(&F->getSymbolTable());
305 SC_DEBUG("Inserting Instructions:\n");
307 // Add all of the instructions to the type planes...
308 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
310 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
312 if (const VANextInst *VAN = dyn_cast<VANextInst>(I))
313 getOrCreateSlot(VAN->getArgType());
317 // If we are building a compaction table, prune out planes that do not benefit
318 // from being compactified.
319 if (!CompactionTable.empty())
320 pruneCompactionTable();
322 SC_DEBUG("end processFunction!\n");
325 void SlotCalculator::purgeFunction() {
326 assert(ModuleLevel.size() != 0 && "Module not incorporated!");
327 unsigned NumModuleTypes = ModuleLevel.size();
329 SC_DEBUG("begin purgeFunction!\n");
331 // First, free the compaction map if used.
332 CompactionNodeMap.clear();
334 // Next, remove values from existing type planes
335 for (unsigned i = 0; i != NumModuleTypes; ++i) {
336 // Size of plane before function came
337 unsigned ModuleLev = getModuleLevel(i);
338 assert(int(ModuleLev) >= 0 && "BAD!");
340 TypePlane &Plane = getPlane(i);
342 assert(ModuleLev <= Plane.size() && "module levels higher than elements?");
343 while (Plane.size() != ModuleLev) {
344 assert(!isa<GlobalValue>(Plane.back()) &&
345 "Functions cannot define globals!");
346 NodeMap.erase(Plane.back()); // Erase from nodemap
347 Plane.pop_back(); // Shrink plane
351 // We don't need this state anymore, free it up.
354 // Finally, remove any type planes defined by the function...
355 if (!CompactionTable.empty()) {
356 CompactionTable.clear();
358 while (Table.size() > NumModuleTypes) {
359 TypePlane &Plane = Table.back();
360 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
361 << Plane.size() << "\n");
362 while (Plane.size()) {
363 assert(!isa<GlobalValue>(Plane.back()) &&
364 "Functions cannot define globals!");
365 NodeMap.erase(Plane.back()); // Erase from nodemap
366 Plane.pop_back(); // Shrink plane
369 Table.pop_back(); // Nuke the plane, we don't like it.
373 SC_DEBUG("end purgeFunction!\n");
376 static inline bool hasNullValue(unsigned TyID) {
377 return TyID != Type::LabelTyID && TyID != Type::TypeTyID &&
378 TyID != Type::VoidTyID;
381 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
382 /// approximation of the compaction table.
383 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Value *V) {
384 std::map<const Value*, unsigned>::iterator I =
385 CompactionNodeMap.lower_bound(V);
386 if (I != CompactionNodeMap.end() && I->first == V)
387 return I->second; // Already exists?
389 // Make sure the type is in the table.
391 if (!CompactionTable[Type::TypeTyID].empty())
392 Ty = getOrCreateCompactionTableSlot(V->getType());
393 else // If the type plane was decompactified, use the global plane ID
394 Ty = getSlot(V->getType());
395 if (CompactionTable.size() <= Ty)
396 CompactionTable.resize(Ty+1);
398 assert(!isa<Type>(V) || ModuleLevel.empty());
400 TypePlane &TyPlane = CompactionTable[Ty];
402 // Make sure to insert the null entry if the thing we are inserting is not a
404 if (TyPlane.empty() && hasNullValue(V->getType()->getPrimitiveID())) {
405 Value *ZeroInitializer = Constant::getNullValue(V->getType());
406 if (V != ZeroInitializer) {
407 TyPlane.push_back(ZeroInitializer);
408 CompactionNodeMap[ZeroInitializer] = 0;
412 unsigned SlotNo = TyPlane.size();
413 TyPlane.push_back(V);
414 CompactionNodeMap.insert(std::make_pair(V, SlotNo));
419 /// buildCompactionTable - Since all of the function constants and types are
420 /// stored in the module-level constant table, we don't need to emit a function
421 /// constant table. Also due to this, the indices for various constants and
422 /// types might be very large in large programs. In order to avoid blowing up
423 /// the size of instructions in the bytecode encoding, we build a compaction
424 /// table, which defines a mapping from function-local identifiers to global
426 void SlotCalculator::buildCompactionTable(const Function *F) {
427 assert(CompactionNodeMap.empty() && "Compaction table already built!");
428 // First step, insert the primitive types.
429 CompactionTable.resize(Type::TypeTyID+1);
430 for (unsigned i = 0; i != Type::FirstDerivedTyID; ++i) {
431 const Type *PrimTy = Type::getPrimitiveType((Type::PrimitiveID)i);
432 CompactionTable[Type::TypeTyID].push_back(PrimTy);
433 CompactionNodeMap[PrimTy] = i;
436 // Next, include any types used by function arguments.
437 for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
438 getOrCreateCompactionTableSlot(I->getType());
440 // Next, find all of the types and values that are referred to by the
441 // instructions in the program.
442 for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
443 getOrCreateCompactionTableSlot(I->getType());
444 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
445 if (isa<Constant>(I->getOperand(op)) ||
446 isa<GlobalValue>(I->getOperand(op)))
447 getOrCreateCompactionTableSlot(I->getOperand(op));
448 if (const VANextInst *VAN = dyn_cast<VANextInst>(*I))
449 getOrCreateCompactionTableSlot(VAN->getArgType());
452 const SymbolTable &ST = F->getSymbolTable();
453 for (SymbolTable::const_iterator I = ST.begin(), E = ST.end(); I != E; ++I)
454 for (SymbolTable::type_const_iterator TI = I->second.begin(),
455 TE = I->second.end(); TI != TE; ++TI)
456 if (isa<Constant>(TI->second) || isa<Type>(TI->second) ||
457 isa<GlobalValue>(TI->second))
458 getOrCreateCompactionTableSlot(TI->second);
460 // Now that we have all of the values in the table, and know what types are
461 // referenced, make sure that there is at least the zero initializer in any
462 // used type plane. Since the type was used, we will be emitting instructions
463 // to the plane even if there are no constants in it.
464 CompactionTable.resize(CompactionTable[Type::TypeTyID].size());
465 for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i)
466 if (CompactionTable[i].empty() && i != Type::VoidTyID &&
467 i != Type::LabelTyID) {
468 const Type *Ty = cast<Type>(CompactionTable[Type::TypeTyID][i]);
469 getOrCreateCompactionTableSlot(Constant::getNullValue(Ty));
472 // Okay, now at this point, we have a legal compaction table. Since we want
473 // to emit the smallest possible binaries, do not compactify the type plane if
474 // it will not save us anything. Because we have not yet incorporated the
475 // function body itself yet, we don't know whether or not it's a good idea to
476 // compactify other planes. We will defer this decision until later.
477 TypePlane &GlobalTypes = Table[Type::TypeTyID];
479 // All of the values types will be scrunched to the start of the types plane
480 // of the global table. Figure out just how many there are.
481 assert(!GlobalTypes.empty() && "No global types???");
482 unsigned NumFCTypes = GlobalTypes.size()-1;
483 while (!cast<Type>(GlobalTypes[NumFCTypes])->isFirstClassType())
486 // If there are fewer that 64 types, no instructions will be exploded due to
487 // the size of the type operands. Thus there is no need to compactify types.
488 // Also, if the compaction table contains most of the entries in the global
489 // table, there really is no reason to compactify either.
490 if (NumFCTypes < 64) {
491 // Decompactifying types is tricky, because we have to move type planes all
492 // over the place. At least we don't need to worry about updating the
493 // CompactionNodeMap for non-types though.
494 std::vector<TypePlane> TmpCompactionTable;
495 std::swap(CompactionTable, TmpCompactionTable);
497 std::swap(Types, TmpCompactionTable[Type::TypeTyID]);
499 // Move each plane back over to the uncompactified plane
500 while (!Types.empty()) {
501 const Type *Ty = cast<Type>(Types.back());
503 CompactionNodeMap.erase(Ty); // Decompactify type!
505 if (Ty != Type::TypeTy) {
506 // Find the global slot number for this type.
507 int TySlot = getSlot(Ty);
508 assert(TySlot != -1 && "Type doesn't exist in global table?");
510 // Now we know where to put the compaction table plane.
511 if (CompactionTable.size() <= unsigned(TySlot))
512 CompactionTable.resize(TySlot+1);
513 // Move the plane back into the compaction table.
514 std::swap(CompactionTable[TySlot], TmpCompactionTable[Types.size()]);
516 // And remove the empty plane we just moved in.
517 TmpCompactionTable.pop_back();
524 /// pruneCompactionTable - Once the entire function being processed has been
525 /// incorporated into the current compaction table, look over the compaction
526 /// table and check to see if there are any values whose compaction will not
527 /// save us any space in the bytecode file. If compactifying these values
528 /// serves no purpose, then we might as well not even emit the compactification
529 /// information to the bytecode file, saving a bit more space.
531 /// Note that the type plane has already been compactified if possible.
533 void SlotCalculator::pruneCompactionTable() {
534 TypePlane &TyPlane = CompactionTable[Type::TypeTyID];
535 for (unsigned ctp = 0, e = CompactionTable.size(); ctp != e; ++ctp)
536 if (ctp != Type::TypeTyID && !CompactionTable[ctp].empty()) {
537 TypePlane &CPlane = CompactionTable[ctp];
538 unsigned GlobalSlot = ctp;
539 if (!TyPlane.empty())
540 GlobalSlot = getGlobalSlot(TyPlane[ctp]);
542 if (GlobalSlot >= Table.size())
543 Table.resize(GlobalSlot+1);
544 TypePlane &GPlane = Table[GlobalSlot];
546 unsigned ModLevel = getModuleLevel(ctp);
547 unsigned NumFunctionObjs = CPlane.size()-ModLevel;
549 // If the maximum index required if all entries in this plane were merged
550 // into the global plane is less than 64, go ahead and eliminate the
552 bool PrunePlane = GPlane.size() + NumFunctionObjs < 64;
554 // If there are no function-local values defined, and the maximum
555 // referenced global entry is less than 64, we don't need to compactify.
556 if (!PrunePlane && NumFunctionObjs == 0) {
558 for (unsigned i = 0; i != ModLevel; ++i) {
559 unsigned Idx = NodeMap[CPlane[i]];
560 if (Idx > MaxIdx) MaxIdx = Idx;
562 PrunePlane = MaxIdx < 64;
565 // Ok, finally, if we decided to prune this plane out of the compaction
569 std::swap(OldPlane, CPlane);
571 // Loop over the function local objects, relocating them to the global
573 for (unsigned i = ModLevel, e = OldPlane.size(); i != e; ++i) {
574 const Value *V = OldPlane[i];
575 CompactionNodeMap.erase(V);
576 assert(NodeMap.count(V) == 0 && "Value already in table??");
580 // For compactified global values, just remove them from the compaction
582 for (unsigned i = 0; i != ModLevel; ++i)
583 CompactionNodeMap.erase(OldPlane[i]);
585 // Update the new modulelevel for this plane.
586 assert(ctp < ModuleLevel.size() && "Cannot set modulelevel!");
587 ModuleLevel[ctp] = GPlane.size()-NumFunctionObjs;
588 assert((int)ModuleLevel[ctp] >= 0 && "Bad computation!");
594 int SlotCalculator::getSlot(const Value *V) const {
595 // If there is a CompactionTable active...
596 if (!CompactionNodeMap.empty()) {
597 std::map<const Value*, unsigned>::const_iterator I =
598 CompactionNodeMap.find(V);
599 if (I != CompactionNodeMap.end())
600 return (int)I->second;
601 // Otherwise, if it's not in the compaction table, it must be in a
602 // non-compactified plane.
605 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
606 if (I != NodeMap.end())
607 return (int)I->second;
609 // Do not number ConstantPointerRef's at all. They are an abomination.
610 if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
611 return getSlot(CPR->getValue());
617 int SlotCalculator::getOrCreateSlot(const Value *V) {
618 if (V->getType() == Type::VoidTy) return -1;
620 int SlotNo = getSlot(V); // Check to see if it's already in!
621 if (SlotNo != -1) return SlotNo;
623 // Do not number ConstantPointerRef's at all. They are an abomination.
624 if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
625 return getOrCreateSlot(CPR->getValue());
627 if (!isa<GlobalValue>(V)) // Initializers for globals are handled explicitly
628 if (const Constant *C = dyn_cast<Constant>(V)) {
629 assert(CompactionNodeMap.empty() &&
630 "All needed constants should be in the compaction map already!");
632 // If we are emitting a bytecode file, do not index the characters that
633 // make up constant strings. We emit constant strings as special
634 // entities that don't require their individual characters to be emitted.
635 if (!BuildBytecodeInfo || !isa<ConstantArray>(C) ||
636 !cast<ConstantArray>(C)->isString()) {
637 // This makes sure that if a constant has uses (for example an array of
638 // const ints), that they are inserted also.
640 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
644 assert(ModuleLevel.empty() &&
645 "How can a constant string be directly accessed in a function?");
646 // Otherwise, if we are emitting a bytecode file and this IS a string,
648 if (!C->isNullValue())
649 ConstantStrings.push_back(cast<ConstantArray>(C));
653 return insertValue(V);
657 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
658 assert(D && "Can't insert a null value!");
659 assert(getSlot(D) == -1 && "Value is already in the table!");
661 // If we are building a compaction map, and if this plane is being compacted,
662 // insert the value into the compaction map, not into the global map.
663 if (!CompactionNodeMap.empty()) {
664 if (D->getType() == Type::VoidTy) return -1; // Do not insert void values
665 assert(!isa<Type>(D) && !isa<Constant>(D) && !isa<GlobalValue>(D) &&
666 "Types, constants, and globals should be in global SymTab!");
668 int Plane = getSlot(D->getType());
669 assert(Plane != -1 && CompactionTable.size() > (unsigned)Plane &&
670 "Didn't find value type!");
671 if (!CompactionTable[Plane].empty())
672 return getOrCreateCompactionTableSlot(D);
675 // If this node does not contribute to a plane, or if the node has a
676 // name and we don't want names, then ignore the silly node... Note that types
677 // do need slot numbers so that we can keep track of where other values land.
679 if (!dontIgnore) // Don't ignore nonignorables!
680 if (D->getType() == Type::VoidTy || // Ignore void type nodes
681 (!BuildBytecodeInfo && // Ignore named and constants
682 (D->hasName() || isa<Constant>(D)) && !isa<Type>(D))) {
683 SC_DEBUG("ignored value " << *D << "\n");
684 return -1; // We do need types unconditionally though
687 // If it's a type, make sure that all subtypes of the type are included...
688 if (const Type *TheTy = dyn_cast<Type>(D)) {
690 // Insert the current type before any subtypes. This is important because
691 // recursive types elements are inserted in a bottom up order. Changing
692 // this here can break things. For example:
694 // global { \2 * } { { \2 }* null }
696 int ResultSlot = doInsertValue(TheTy);
697 SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
700 // Loop over any contained types in the definition... in post
703 for (po_iterator<const Type*> I = po_begin(TheTy), E = po_end(TheTy);
706 const Type *SubTy = *I;
707 // If we haven't seen this sub type before, add it to our type table!
708 if (getSlot(SubTy) == -1) {
709 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
710 int Slot = doInsertValue(SubTy);
711 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
712 " slot=" << Slot << "\n");
719 // Okay, everything is happy, actually insert the silly value now...
720 return doInsertValue(D);
723 // doInsertValue - This is a small helper function to be called only
726 int SlotCalculator::doInsertValue(const Value *D) {
727 const Type *Typ = D->getType();
730 // Used for debugging DefSlot=-1 assertion...
731 //if (Typ == Type::TypeTy)
732 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
734 if (Typ->isDerivedType()) {
736 if (CompactionTable.empty())
737 ValSlot = getSlot(Typ);
739 ValSlot = getGlobalSlot(Typ);
740 if (ValSlot == -1) { // Have we already entered this type?
741 // Nope, this is the first we have seen the type, process it.
742 ValSlot = insertValue(Typ, true);
743 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
745 Ty = (unsigned)ValSlot;
747 Ty = Typ->getPrimitiveID();
750 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
751 Table.resize(Ty+1, TypePlane());
753 // If this is the first value to get inserted into the type plane, make sure
754 // to insert the implicit null value...
755 if (Table[Ty].empty() && BuildBytecodeInfo && hasNullValue(Ty)) {
756 Value *ZeroInitializer = Constant::getNullValue(Typ);
758 // If we are pushing zeroinit, it will be handled below.
759 if (D != ZeroInitializer) {
760 Table[Ty].push_back(ZeroInitializer);
761 NodeMap[ZeroInitializer] = 0;
765 // Insert node into table and NodeMap...
766 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
767 Table[Ty].push_back(D);
769 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
771 // G = Global, C = Constant, T = Type, F = Function, o = other
772 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
773 (isa<Type>(D) ? "T" : (isa<Function>(D) ? "F" : "o")))));
775 return (int)DestSlot;