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 "SlotCalculator.h"
18 #include "llvm/Constants.h"
19 #include "llvm/DerivedTypes.h"
20 #include "llvm/Function.h"
21 #include "llvm/Instructions.h"
22 #include "llvm/Module.h"
23 #include "llvm/SymbolTable.h"
24 #include "llvm/Type.h"
25 #include "llvm/Analysis/ConstantsScanner.h"
26 #include "llvm/ADT/PostOrderIterator.h"
27 #include "llvm/ADT/STLExtras.h"
35 #define SC_DEBUG(X) std::cerr << X
40 SlotCalculator::SlotCalculator(const Module *M ) {
41 ModuleContainsAllFunctionConstants = false;
45 // Preload table... Make sure that all of the primitive types are in the table
46 // and that their Primitive ID is equal to their slot #
48 SC_DEBUG("Inserting primitive types:\n");
49 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
50 assert(Type::getPrimitiveType((Type::TypeID)i));
51 insertType(Type::getPrimitiveType((Type::TypeID)i), true);
54 if (M == 0) return; // Empty table...
58 SlotCalculator::SlotCalculator(const Function *M ) {
59 ModuleContainsAllFunctionConstants = false;
60 TheModule = M ? M->getParent() : 0;
62 // Preload table... Make sure that all of the primitive types are in the table
63 // and that their Primitive ID is equal to their slot #
65 SC_DEBUG("Inserting primitive types:\n");
66 for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
67 assert(Type::getPrimitiveType((Type::TypeID)i));
68 insertType(Type::getPrimitiveType((Type::TypeID)i), true);
71 if (TheModule == 0) return; // Empty table...
73 processModule(); // Process module level stuff
74 incorporateFunction(M); // Start out in incorporated state
77 unsigned SlotCalculator::getGlobalSlot(const Value *V) const {
78 assert(!CompactionTable.empty() &&
79 "This method can only be used when compaction is enabled!");
80 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
81 assert(I != NodeMap.end() && "Didn't find global slot entry!");
85 unsigned SlotCalculator::getGlobalSlot(const Type* T) const {
86 std::map<const Type*, unsigned>::const_iterator I = TypeMap.find(T);
87 assert(I != TypeMap.end() && "Didn't find global slot entry!");
91 SlotCalculator::TypePlane &SlotCalculator::getPlane(unsigned Plane) {
92 if (CompactionTable.empty()) { // No compaction table active?
94 } else if (!CompactionTable[Plane].empty()) { // Compaction table active.
95 assert(Plane < CompactionTable.size());
96 return CompactionTable[Plane];
98 // Final case: compaction table active, but this plane is not
99 // compactified. If the type plane is compactified, unmap back to the
100 // global type plane corresponding to "Plane".
101 if (!CompactionTypes.empty()) {
102 const Type *Ty = CompactionTypes[Plane];
103 TypeMapType::iterator It = TypeMap.find(Ty);
104 assert(It != TypeMap.end() && "Type not in global constant map?");
109 // Okay we are just returning an entry out of the main Table. Make sure the
110 // plane exists and return it.
111 if (Plane >= Table.size())
112 Table.resize(Plane+1);
116 // processModule - Process all of the module level function declarations and
117 // types that are available.
119 void SlotCalculator::processModule() {
120 SC_DEBUG("begin processModule!\n");
122 // Add all of the global variables to the value table...
124 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
128 // Scavenge the types out of the functions, then add the functions themselves
129 // to the value table...
131 for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
135 // Add all of the module level constants used as initializers
137 for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
139 if (I->hasInitializer())
140 getOrCreateSlot(I->getInitializer());
142 // Now that all global constants have been added, rearrange constant planes
143 // that contain constant strings so that the strings occur at the start of the
144 // plane, not somewhere in the middle.
146 for (unsigned plane = 0, e = Table.size(); plane != e; ++plane) {
147 if (const ArrayType *AT = dyn_cast<ArrayType>(Types[plane]))
148 if (AT->getElementType() == Type::SByteTy ||
149 AT->getElementType() == Type::UByteTy) {
150 TypePlane &Plane = Table[plane];
151 unsigned FirstNonStringID = 0;
152 for (unsigned i = 0, e = Plane.size(); i != e; ++i)
153 if (isa<ConstantAggregateZero>(Plane[i]) ||
154 (isa<ConstantArray>(Plane[i]) &&
155 cast<ConstantArray>(Plane[i])->isString())) {
156 // Check to see if we have to shuffle this string around. If not,
157 // don't do anything.
158 if (i != FirstNonStringID) {
159 // Swap the plane entries....
160 std::swap(Plane[i], Plane[FirstNonStringID]);
162 // Keep the NodeMap up to date.
163 NodeMap[Plane[i]] = i;
164 NodeMap[Plane[FirstNonStringID]] = FirstNonStringID;
171 // Scan all of the functions for their constants, which allows us to emit
172 // more compact modules. This is optional, and is just used to compactify
173 // the constants used by different functions together.
175 // This functionality tends to produce smaller bytecode files. This should
176 // not be used in the future by clients that want to, for example, build and
177 // emit functions on the fly. For now, however, it is unconditionally
179 ModuleContainsAllFunctionConstants = true;
181 SC_DEBUG("Inserting function constants:\n");
182 for (Module::const_iterator F = TheModule->begin(), E = TheModule->end();
184 for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I){
185 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
186 if (isa<Constant>(I->getOperand(op)) &&
187 !isa<GlobalValue>(I->getOperand(op)))
188 getOrCreateSlot(I->getOperand(op));
189 getOrCreateSlot(I->getType());
190 if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I))
191 getOrCreateSlot(VAN->getArgType());
193 processSymbolTableConstants(&F->getSymbolTable());
196 // Insert constants that are named at module level into the slot pool so that
197 // the module symbol table can refer to them...
198 SC_DEBUG("Inserting SymbolTable values:\n");
199 processSymbolTable(&TheModule->getSymbolTable());
201 // Now that we have collected together all of the information relevant to the
202 // module, compactify the type table if it is particularly big and outputting
203 // a bytecode file. The basic problem we run into is that some programs have
204 // a large number of types, which causes the type field to overflow its size,
205 // which causes instructions to explode in size (particularly call
206 // instructions). To avoid this behavior, we "sort" the type table so that
207 // all non-value types are pushed to the end of the type table, giving nice
208 // low numbers to the types that can be used by instructions, thus reducing
209 // the amount of explodage we suffer.
210 if (Types.size() >= 64) {
211 unsigned FirstNonValueTypeID = 0;
212 for (unsigned i = 0, e = Types.size(); i != e; ++i)
213 if (Types[i]->isFirstClassType() || Types[i]->isPrimitiveType()) {
214 // Check to see if we have to shuffle this type around. If not, don't
216 if (i != FirstNonValueTypeID) {
217 // Swap the type ID's.
218 std::swap(Types[i], Types[FirstNonValueTypeID]);
220 // Keep the TypeMap up to date.
221 TypeMap[Types[i]] = i;
222 TypeMap[Types[FirstNonValueTypeID]] = FirstNonValueTypeID;
224 // When we move a type, make sure to move its value plane as needed.
225 if (Table.size() > FirstNonValueTypeID) {
226 if (Table.size() <= i) Table.resize(i+1);
227 std::swap(Table[i], Table[FirstNonValueTypeID]);
230 ++FirstNonValueTypeID;
234 SC_DEBUG("end processModule!\n");
237 // processSymbolTable - Insert all of the values in the specified symbol table
238 // into the values table...
240 void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
241 // Do the types first.
242 for (SymbolTable::type_const_iterator TI = ST->type_begin(),
243 TE = ST->type_end(); TI != TE; ++TI )
244 getOrCreateSlot(TI->second);
246 // Now do the values.
247 for (SymbolTable::plane_const_iterator PI = ST->plane_begin(),
248 PE = ST->plane_end(); PI != PE; ++PI)
249 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
250 VE = PI->second.end(); VI != VE; ++VI)
251 getOrCreateSlot(VI->second);
254 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
255 // Do the types first
256 for (SymbolTable::type_const_iterator TI = ST->type_begin(),
257 TE = ST->type_end(); TI != TE; ++TI )
258 getOrCreateSlot(TI->second);
260 // Now do the constant values in all planes
261 for (SymbolTable::plane_const_iterator PI = ST->plane_begin(),
262 PE = ST->plane_end(); PI != PE; ++PI)
263 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
264 VE = PI->second.end(); VI != VE; ++VI)
265 if (isa<Constant>(VI->second) &&
266 !isa<GlobalValue>(VI->second))
267 getOrCreateSlot(VI->second);
271 void SlotCalculator::incorporateFunction(const Function *F) {
272 assert((ModuleLevel.size() == 0 ||
273 ModuleTypeLevel == 0) && "Module already incorporated!");
275 SC_DEBUG("begin processFunction!\n");
277 // If we emitted all of the function constants, build a compaction table.
278 if ( ModuleContainsAllFunctionConstants)
279 buildCompactionTable(F);
281 // Update the ModuleLevel entries to be accurate.
282 ModuleLevel.resize(getNumPlanes());
283 for (unsigned i = 0, e = getNumPlanes(); i != e; ++i)
284 ModuleLevel[i] = getPlane(i).size();
285 ModuleTypeLevel = Types.size();
287 // Iterate over function arguments, adding them to the value table...
288 for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
291 if ( !ModuleContainsAllFunctionConstants ) {
292 // Iterate over all of the instructions in the function, looking for
293 // constant values that are referenced. Add these to the value pools
294 // before any nonconstant values. This will be turned into the constant
295 // pool for the bytecode writer.
298 // Emit all of the constants that are being used by the instructions in
300 constant_iterator CI = constant_begin(F);
301 constant_iterator CE = constant_end(F);
303 this->getOrCreateSlot(*CI);
307 // If there is a symbol table, it is possible that the user has names for
308 // constants that are not being used. In this case, we will have problems
309 // if we don't emit the constants now, because otherwise we will get
310 // symbol table references to constants not in the output. Scan for these
313 processSymbolTableConstants(&F->getSymbolTable());
316 SC_DEBUG("Inserting Instructions:\n");
318 // Add all of the instructions to the type planes...
319 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
321 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
323 if (const VANextInst *VAN = dyn_cast<VANextInst>(I))
324 getOrCreateSlot(VAN->getArgType());
328 // If we are building a compaction table, prune out planes that do not benefit
329 // from being compactified.
330 if (!CompactionTable.empty())
331 pruneCompactionTable();
333 SC_DEBUG("end processFunction!\n");
336 void SlotCalculator::purgeFunction() {
337 assert((ModuleLevel.size() != 0 ||
338 ModuleTypeLevel != 0) && "Module not incorporated!");
339 unsigned NumModuleTypes = ModuleLevel.size();
341 SC_DEBUG("begin purgeFunction!\n");
343 // First, free the compaction map if used.
344 CompactionNodeMap.clear();
345 CompactionTypeMap.clear();
347 // Next, remove values from existing type planes
348 for (unsigned i = 0; i != NumModuleTypes; ++i) {
349 // Size of plane before function came
350 unsigned ModuleLev = getModuleLevel(i);
351 assert(int(ModuleLev) >= 0 && "BAD!");
353 TypePlane &Plane = getPlane(i);
355 assert(ModuleLev <= Plane.size() && "module levels higher than elements?");
356 while (Plane.size() != ModuleLev) {
357 assert(!isa<GlobalValue>(Plane.back()) &&
358 "Functions cannot define globals!");
359 NodeMap.erase(Plane.back()); // Erase from nodemap
360 Plane.pop_back(); // Shrink plane
364 // We don't need this state anymore, free it up.
368 // Finally, remove any type planes defined by the function...
369 CompactionTypes.clear();
370 if (!CompactionTable.empty()) {
371 CompactionTable.clear();
373 while (Table.size() > NumModuleTypes) {
374 TypePlane &Plane = Table.back();
375 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
376 << Plane.size() << "\n");
377 while (Plane.size()) {
378 assert(!isa<GlobalValue>(Plane.back()) &&
379 "Functions cannot define globals!");
380 NodeMap.erase(Plane.back()); // Erase from nodemap
381 Plane.pop_back(); // Shrink plane
384 Table.pop_back(); // Nuke the plane, we don't like it.
388 SC_DEBUG("end purgeFunction!\n");
391 static inline bool hasNullValue(unsigned TyID) {
392 return TyID != Type::LabelTyID && TyID != Type::VoidTyID;
395 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
396 /// approximation of the compaction table.
397 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Value *V) {
398 std::map<const Value*, unsigned>::iterator I =
399 CompactionNodeMap.lower_bound(V);
400 if (I != CompactionNodeMap.end() && I->first == V)
401 return I->second; // Already exists?
403 // Make sure the type is in the table.
405 if (!CompactionTypes.empty())
406 Ty = getOrCreateCompactionTableSlot(V->getType());
407 else // If the type plane was decompactified, use the global plane ID
408 Ty = getSlot(V->getType());
409 if (CompactionTable.size() <= Ty)
410 CompactionTable.resize(Ty+1);
412 TypePlane &TyPlane = CompactionTable[Ty];
414 // Make sure to insert the null entry if the thing we are inserting is not a
416 if (TyPlane.empty() && hasNullValue(V->getType()->getTypeID())) {
417 Value *ZeroInitializer = Constant::getNullValue(V->getType());
418 if (V != ZeroInitializer) {
419 TyPlane.push_back(ZeroInitializer);
420 CompactionNodeMap[ZeroInitializer] = 0;
424 unsigned SlotNo = TyPlane.size();
425 TyPlane.push_back(V);
426 CompactionNodeMap.insert(std::make_pair(V, SlotNo));
430 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
431 /// approximation of the compaction table.
432 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Type *T) {
433 std::map<const Type*, unsigned>::iterator I =
434 CompactionTypeMap.lower_bound(T);
435 if (I != CompactionTypeMap.end() && I->first == T)
436 return I->second; // Already exists?
438 unsigned SlotNo = CompactionTypes.size();
439 SC_DEBUG("Inserting Compaction Type #" << SlotNo << ": " << T << "\n");
440 CompactionTypes.push_back(T);
441 CompactionTypeMap.insert(std::make_pair(T, SlotNo));
445 /// buildCompactionTable - Since all of the function constants and types are
446 /// stored in the module-level constant table, we don't need to emit a function
447 /// constant table. Also due to this, the indices for various constants and
448 /// types might be very large in large programs. In order to avoid blowing up
449 /// the size of instructions in the bytecode encoding, we build a compaction
450 /// table, which defines a mapping from function-local identifiers to global
452 void SlotCalculator::buildCompactionTable(const Function *F) {
453 assert(CompactionNodeMap.empty() && "Compaction table already built!");
454 assert(CompactionTypeMap.empty() && "Compaction types already built!");
455 // First step, insert the primitive types.
456 CompactionTable.resize(Type::LastPrimitiveTyID+1);
457 for (unsigned i = 0; i <= Type::LastPrimitiveTyID; ++i) {
458 const Type *PrimTy = Type::getPrimitiveType((Type::TypeID)i);
459 CompactionTypes.push_back(PrimTy);
460 CompactionTypeMap[PrimTy] = i;
463 // Next, include any types used by function arguments.
464 for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
465 getOrCreateCompactionTableSlot(I->getType());
467 // Next, find all of the types and values that are referred to by the
468 // instructions in the function.
469 for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
470 getOrCreateCompactionTableSlot(I->getType());
471 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
472 if (isa<Constant>(I->getOperand(op)))
473 getOrCreateCompactionTableSlot(I->getOperand(op));
474 if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I))
475 getOrCreateCompactionTableSlot(VAN->getArgType());
478 // Do the types in the symbol table
479 const SymbolTable &ST = F->getSymbolTable();
480 for (SymbolTable::type_const_iterator TI = ST.type_begin(),
481 TE = ST.type_end(); TI != TE; ++TI)
482 getOrCreateCompactionTableSlot(TI->second);
484 // Now do the constants and global values
485 for (SymbolTable::plane_const_iterator PI = ST.plane_begin(),
486 PE = ST.plane_end(); PI != PE; ++PI)
487 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
488 VE = PI->second.end(); VI != VE; ++VI)
489 if (isa<Constant>(VI->second) && !isa<GlobalValue>(VI->second))
490 getOrCreateCompactionTableSlot(VI->second);
492 // Now that we have all of the values in the table, and know what types are
493 // referenced, make sure that there is at least the zero initializer in any
494 // used type plane. Since the type was used, we will be emitting instructions
495 // to the plane even if there are no constants in it.
496 CompactionTable.resize(CompactionTypes.size());
497 for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i)
498 if (CompactionTable[i].empty() && (i != Type::VoidTyID) &&
499 i != Type::LabelTyID) {
500 const Type *Ty = CompactionTypes[i];
501 SC_DEBUG("Getting Null Value #" << i << " for Type " << Ty << "\n");
502 assert(Ty->getTypeID() != Type::VoidTyID);
503 assert(Ty->getTypeID() != Type::LabelTyID);
504 getOrCreateCompactionTableSlot(Constant::getNullValue(Ty));
507 // Okay, now at this point, we have a legal compaction table. Since we want
508 // to emit the smallest possible binaries, do not compactify the type plane if
509 // it will not save us anything. Because we have not yet incorporated the
510 // function body itself yet, we don't know whether or not it's a good idea to
511 // compactify other planes. We will defer this decision until later.
512 TypeList &GlobalTypes = Types;
514 // All of the values types will be scrunched to the start of the types plane
515 // of the global table. Figure out just how many there are.
516 assert(!GlobalTypes.empty() && "No global types???");
517 unsigned NumFCTypes = GlobalTypes.size()-1;
518 while (!GlobalTypes[NumFCTypes]->isFirstClassType())
521 // If there are fewer that 64 types, no instructions will be exploded due to
522 // the size of the type operands. Thus there is no need to compactify types.
523 // Also, if the compaction table contains most of the entries in the global
524 // table, there really is no reason to compactify either.
525 if (NumFCTypes < 64) {
526 // Decompactifying types is tricky, because we have to move type planes all
527 // over the place. At least we don't need to worry about updating the
528 // CompactionNodeMap for non-types though.
529 std::vector<TypePlane> TmpCompactionTable;
530 std::swap(CompactionTable, TmpCompactionTable);
532 std::swap(TmpTypes, CompactionTypes);
534 // Move each plane back over to the uncompactified plane
535 while (!TmpTypes.empty()) {
536 const Type *Ty = TmpTypes.back();
538 CompactionTypeMap.erase(Ty); // Decompactify type!
540 // Find the global slot number for this type.
541 int TySlot = getSlot(Ty);
542 assert(TySlot != -1 && "Type doesn't exist in global table?");
544 // Now we know where to put the compaction table plane.
545 if (CompactionTable.size() <= unsigned(TySlot))
546 CompactionTable.resize(TySlot+1);
547 // Move the plane back into the compaction table.
548 std::swap(CompactionTable[TySlot], TmpCompactionTable[TmpTypes.size()]);
550 // And remove the empty plane we just moved in.
551 TmpCompactionTable.pop_back();
557 /// pruneCompactionTable - Once the entire function being processed has been
558 /// incorporated into the current compaction table, look over the compaction
559 /// table and check to see if there are any values whose compaction will not
560 /// save us any space in the bytecode file. If compactifying these values
561 /// serves no purpose, then we might as well not even emit the compactification
562 /// information to the bytecode file, saving a bit more space.
564 /// Note that the type plane has already been compactified if possible.
566 void SlotCalculator::pruneCompactionTable() {
567 TypeList &TyPlane = CompactionTypes;
568 for (unsigned ctp = 0, e = CompactionTable.size(); ctp != e; ++ctp)
569 if (!CompactionTable[ctp].empty()) {
570 TypePlane &CPlane = CompactionTable[ctp];
571 unsigned GlobalSlot = ctp;
572 if (!TyPlane.empty())
573 GlobalSlot = getGlobalSlot(TyPlane[ctp]);
575 if (GlobalSlot >= Table.size())
576 Table.resize(GlobalSlot+1);
577 TypePlane &GPlane = Table[GlobalSlot];
579 unsigned ModLevel = getModuleLevel(ctp);
580 unsigned NumFunctionObjs = CPlane.size()-ModLevel;
582 // If the maximum index required if all entries in this plane were merged
583 // into the global plane is less than 64, go ahead and eliminate the
585 bool PrunePlane = GPlane.size() + NumFunctionObjs < 64;
587 // If there are no function-local values defined, and the maximum
588 // referenced global entry is less than 64, we don't need to compactify.
589 if (!PrunePlane && NumFunctionObjs == 0) {
591 for (unsigned i = 0; i != ModLevel; ++i) {
592 unsigned Idx = NodeMap[CPlane[i]];
593 if (Idx > MaxIdx) MaxIdx = Idx;
595 PrunePlane = MaxIdx < 64;
598 // Ok, finally, if we decided to prune this plane out of the compaction
602 std::swap(OldPlane, CPlane);
604 // Loop over the function local objects, relocating them to the global
606 for (unsigned i = ModLevel, e = OldPlane.size(); i != e; ++i) {
607 const Value *V = OldPlane[i];
608 CompactionNodeMap.erase(V);
609 assert(NodeMap.count(V) == 0 && "Value already in table??");
613 // For compactified global values, just remove them from the compaction
615 for (unsigned i = 0; i != ModLevel; ++i)
616 CompactionNodeMap.erase(OldPlane[i]);
618 // Update the new modulelevel for this plane.
619 assert(ctp < ModuleLevel.size() && "Cannot set modulelevel!");
620 ModuleLevel[ctp] = GPlane.size()-NumFunctionObjs;
621 assert((int)ModuleLevel[ctp] >= 0 && "Bad computation!");
626 /// Determine if the compaction table is actually empty. Because the
627 /// compaction table always includes the primitive type planes, we
628 /// can't just check getCompactionTable().size() because it will never
629 /// be zero. Furthermore, the ModuleLevel factors into whether a given
630 /// plane is empty or not. This function does the necessary computation
631 /// to determine if its actually empty.
632 bool SlotCalculator::CompactionTableIsEmpty() const {
633 // Check a degenerate case, just in case.
634 if (CompactionTable.size() == 0) return true;
637 for (unsigned i = 0, e = CompactionTable.size(); i < e; ++i) {
638 // If the plane is not empty
639 if (!CompactionTable[i].empty()) {
640 // If the module level is non-zero then at least the
641 // first element of the plane is valid and therefore not empty.
642 unsigned End = getModuleLevel(i);
647 // All the compaction table planes are empty so the table is
648 // considered empty too.
652 int SlotCalculator::getSlot(const Value *V) const {
653 // If there is a CompactionTable active...
654 if (!CompactionNodeMap.empty()) {
655 std::map<const Value*, unsigned>::const_iterator I =
656 CompactionNodeMap.find(V);
657 if (I != CompactionNodeMap.end())
658 return (int)I->second;
659 // Otherwise, if it's not in the compaction table, it must be in a
660 // non-compactified plane.
663 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
664 if (I != NodeMap.end())
665 return (int)I->second;
670 int SlotCalculator::getSlot(const Type*T) const {
671 // If there is a CompactionTable active...
672 if (!CompactionTypeMap.empty()) {
673 std::map<const Type*, unsigned>::const_iterator I =
674 CompactionTypeMap.find(T);
675 if (I != CompactionTypeMap.end())
676 return (int)I->second;
677 // Otherwise, if it's not in the compaction table, it must be in a
678 // non-compactified plane.
681 std::map<const Type*, unsigned>::const_iterator I = TypeMap.find(T);
682 if (I != TypeMap.end())
683 return (int)I->second;
688 int SlotCalculator::getOrCreateSlot(const Value *V) {
689 if (V->getType() == Type::VoidTy) return -1;
691 int SlotNo = getSlot(V); // Check to see if it's already in!
692 if (SlotNo != -1) return SlotNo;
694 if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
695 assert(GV->getParent() != 0 && "Global not embedded into a module!");
697 if (!isa<GlobalValue>(V)) // Initializers for globals are handled explicitly
698 if (const Constant *C = dyn_cast<Constant>(V)) {
699 assert(CompactionNodeMap.empty() &&
700 "All needed constants should be in the compaction map already!");
702 // Do not index the characters that make up constant strings. We emit
703 // constant strings as special entities that don't require their
704 // individual characters to be emitted.
705 if (!isa<ConstantArray>(C) || !cast<ConstantArray>(C)->isString()) {
706 // This makes sure that if a constant has uses (for example an array of
707 // const ints), that they are inserted also.
709 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
713 assert(ModuleLevel.empty() &&
714 "How can a constant string be directly accessed in a function?");
715 // Otherwise, if we are emitting a bytecode file and this IS a string,
717 if (!C->isNullValue())
718 ConstantStrings.push_back(cast<ConstantArray>(C));
722 return insertValue(V);
725 int SlotCalculator::getOrCreateSlot(const Type* T) {
726 int SlotNo = getSlot(T); // Check to see if it's already in!
727 if (SlotNo != -1) return SlotNo;
728 return insertType(T);
731 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
732 assert(D && "Can't insert a null value!");
733 assert(getSlot(D) == -1 && "Value is already in the table!");
735 // If we are building a compaction map, and if this plane is being compacted,
736 // insert the value into the compaction map, not into the global map.
737 if (!CompactionNodeMap.empty()) {
738 if (D->getType() == Type::VoidTy) return -1; // Do not insert void values
739 assert(!isa<Constant>(D) &&
740 "Types, constants, and globals should be in global table!");
742 int Plane = getSlot(D->getType());
743 assert(Plane != -1 && CompactionTable.size() > (unsigned)Plane &&
744 "Didn't find value type!");
745 if (!CompactionTable[Plane].empty())
746 return getOrCreateCompactionTableSlot(D);
749 // If this node does not contribute to a plane, or if the node has a
750 // name and we don't want names, then ignore the silly node... Note that types
751 // do need slot numbers so that we can keep track of where other values land.
753 if (!dontIgnore) // Don't ignore nonignorables!
754 if (D->getType() == Type::VoidTy ) { // Ignore void type nodes
755 SC_DEBUG("ignored value " << *D << "\n");
756 return -1; // We do need types unconditionally though
759 // Okay, everything is happy, actually insert the silly value now...
760 return doInsertValue(D);
763 int SlotCalculator::insertType(const Type *Ty, bool dontIgnore) {
764 assert(Ty && "Can't insert a null type!");
765 assert(getSlot(Ty) == -1 && "Type is already in the table!");
767 // If we are building a compaction map, and if this plane is being compacted,
768 // insert the value into the compaction map, not into the global map.
769 if (!CompactionTypeMap.empty()) {
770 getOrCreateCompactionTableSlot(Ty);
773 // Insert the current type before any subtypes. This is important because
774 // recursive types elements are inserted in a bottom up order. Changing
775 // this here can break things. For example:
777 // global { \2 * } { { \2 }* null }
779 int ResultSlot = doInsertType(Ty);
780 SC_DEBUG(" Inserted type: " << Ty->getDescription() << " slot=" <<
783 // Loop over any contained types in the definition... in post
785 for (po_iterator<const Type*> I = po_begin(Ty), E = po_end(Ty);
788 const Type *SubTy = *I;
789 // If we haven't seen this sub type before, add it to our type table!
790 if (getSlot(SubTy) == -1) {
791 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
793 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() << "\n");
800 // doInsertValue - This is a small helper function to be called only
803 int SlotCalculator::doInsertValue(const Value *D) {
804 const Type *Typ = D->getType();
807 // Used for debugging DefSlot=-1 assertion...
808 //if (Typ == Type::TypeTy)
809 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
811 if (Typ->isDerivedType()) {
813 if (CompactionTable.empty())
814 ValSlot = getSlot(Typ);
816 ValSlot = getGlobalSlot(Typ);
817 if (ValSlot == -1) { // Have we already entered this type?
818 // Nope, this is the first we have seen the type, process it.
819 ValSlot = insertType(Typ, true);
820 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
822 Ty = (unsigned)ValSlot;
824 Ty = Typ->getTypeID();
827 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
828 Table.resize(Ty+1, TypePlane());
830 // If this is the first value to get inserted into the type plane, make sure
831 // to insert the implicit null value...
832 if (Table[Ty].empty() && hasNullValue(Ty)) {
833 Value *ZeroInitializer = Constant::getNullValue(Typ);
835 // If we are pushing zeroinit, it will be handled below.
836 if (D != ZeroInitializer) {
837 Table[Ty].push_back(ZeroInitializer);
838 NodeMap[ZeroInitializer] = 0;
842 // Insert node into table and NodeMap...
843 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
844 Table[Ty].push_back(D);
846 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
848 // G = Global, C = Constant, T = Type, F = Function, o = other
849 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
850 (isa<Function>(D) ? "F" : "o"))));
852 return (int)DestSlot;
855 // doInsertType - This is a small helper function to be called only
858 int SlotCalculator::doInsertType(const Type *Ty) {
860 // Insert node into table and NodeMap...
861 unsigned DestSlot = TypeMap[Ty] = Types.size();
864 SC_DEBUG(" Inserting type [" << DestSlot << "] = " << Ty << "\n" );
865 return (int)DestSlot;