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 "Support/PostOrderIterator.h"
27 #include "Support/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 cast<ConstantArray>(Plane[i])->isString()) {
155 // Check to see if we have to shuffle this string around. If not,
156 // don't do anything.
157 if (i != FirstNonStringID) {
158 // Swap the plane entries....
159 std::swap(Plane[i], Plane[FirstNonStringID]);
161 // Keep the NodeMap up to date.
162 NodeMap[Plane[i]] = i;
163 NodeMap[Plane[FirstNonStringID]] = FirstNonStringID;
170 // Scan all of the functions for their constants, which allows us to emit
171 // more compact modules. This is optional, and is just used to compactify
172 // the constants used by different functions together.
174 // This functionality tends to produce smaller bytecode files. This should
175 // not be used in the future by clients that want to, for example, build and
176 // emit functions on the fly. For now, however, it is unconditionally
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 !isa<GlobalValue>(I->getOperand(op)))
187 getOrCreateSlot(I->getOperand(op));
188 getOrCreateSlot(I->getType());
189 if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I))
190 getOrCreateSlot(VAN->getArgType());
192 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...
197 SC_DEBUG("Inserting SymbolTable values:\n");
198 processSymbolTable(&TheModule->getSymbolTable());
200 // Now that we have collected together all of the information relevant to the
201 // module, compactify the type table if it is particularly big and outputting
202 // a bytecode file. The basic problem we run into is that some programs have
203 // a large number of types, which causes the type field to overflow its size,
204 // which causes instructions to explode in size (particularly call
205 // instructions). To avoid this behavior, we "sort" the type table so that
206 // all non-value types are pushed to the end of the type table, giving nice
207 // low numbers to the types that can be used by instructions, thus reducing
208 // the amount of explodage we suffer.
209 if (Types.size() >= 64) {
210 unsigned FirstNonValueTypeID = 0;
211 for (unsigned i = 0, e = Types.size(); i != e; ++i)
212 if (Types[i]->isFirstClassType() || Types[i]->isPrimitiveType()) {
213 // Check to see if we have to shuffle this type around. If not, don't
215 if (i != FirstNonValueTypeID) {
216 // Swap the type ID's.
217 std::swap(Types[i], Types[FirstNonValueTypeID]);
219 // Keep the TypeMap up to date.
220 TypeMap[Types[i]] = i;
221 TypeMap[Types[FirstNonValueTypeID]] = FirstNonValueTypeID;
223 // When we move a type, make sure to move its value plane as needed.
224 if (Table.size() > FirstNonValueTypeID) {
225 if (Table.size() <= i) Table.resize(i+1);
226 std::swap(Table[i], Table[FirstNonValueTypeID]);
229 ++FirstNonValueTypeID;
233 SC_DEBUG("end processModule!\n");
236 // processSymbolTable - Insert all of the values in the specified symbol table
237 // into the values table...
239 void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
240 // Do the types first.
241 for (SymbolTable::type_const_iterator TI = ST->type_begin(),
242 TE = ST->type_end(); TI != TE; ++TI )
243 getOrCreateSlot(TI->second);
245 // Now do the values.
246 for (SymbolTable::plane_const_iterator PI = ST->plane_begin(),
247 PE = ST->plane_end(); PI != PE; ++PI)
248 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
249 VE = PI->second.end(); VI != VE; ++VI)
250 getOrCreateSlot(VI->second);
253 void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
254 // Do the types first
255 for (SymbolTable::type_const_iterator TI = ST->type_begin(),
256 TE = ST->type_end(); TI != TE; ++TI )
257 getOrCreateSlot(TI->second);
259 // Now do the constant values in all planes
260 for (SymbolTable::plane_const_iterator PI = ST->plane_begin(),
261 PE = ST->plane_end(); PI != PE; ++PI)
262 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
263 VE = PI->second.end(); VI != VE; ++VI)
264 if (isa<Constant>(VI->second) &&
265 !isa<GlobalValue>(VI->second))
266 getOrCreateSlot(VI->second);
270 void SlotCalculator::incorporateFunction(const Function *F) {
271 assert((ModuleLevel.size() == 0 ||
272 ModuleTypeLevel == 0) && "Module already incorporated!");
274 SC_DEBUG("begin processFunction!\n");
276 // If we emitted all of the function constants, build a compaction table.
277 if ( ModuleContainsAllFunctionConstants)
278 buildCompactionTable(F);
280 // Update the ModuleLevel entries to be accurate.
281 ModuleLevel.resize(getNumPlanes());
282 for (unsigned i = 0, e = getNumPlanes(); i != e; ++i)
283 ModuleLevel[i] = getPlane(i).size();
284 ModuleTypeLevel = Types.size();
286 // Iterate over function arguments, adding them to the value table...
287 for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
290 if ( !ModuleContainsAllFunctionConstants ) {
291 // Iterate over all of the instructions in the function, looking for
292 // constant values that are referenced. Add these to the value pools
293 // before any nonconstant values. This will be turned into the constant
294 // pool for the bytecode writer.
297 // Emit all of the constants that are being used by the instructions in
299 constant_iterator CI = constant_begin(F);
300 constant_iterator CE = constant_end(F);
302 this->getOrCreateSlot(*CI);
306 // If there is a symbol table, it is possible that the user has names for
307 // constants that are not being used. In this case, we will have problems
308 // if we don't emit the constants now, because otherwise we will get
309 // symbol table references to constants not in the output. Scan for these
312 processSymbolTableConstants(&F->getSymbolTable());
315 SC_DEBUG("Inserting Instructions:\n");
317 // Add all of the instructions to the type planes...
318 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
320 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
322 if (const VANextInst *VAN = dyn_cast<VANextInst>(I))
323 getOrCreateSlot(VAN->getArgType());
327 // If we are building a compaction table, prune out planes that do not benefit
328 // from being compactified.
329 if (!CompactionTable.empty())
330 pruneCompactionTable();
332 SC_DEBUG("end processFunction!\n");
335 void SlotCalculator::purgeFunction() {
336 assert((ModuleLevel.size() != 0 ||
337 ModuleTypeLevel != 0) && "Module not incorporated!");
338 unsigned NumModuleTypes = ModuleLevel.size();
340 SC_DEBUG("begin purgeFunction!\n");
342 // First, free the compaction map if used.
343 CompactionNodeMap.clear();
344 CompactionTypeMap.clear();
346 // Next, remove values from existing type planes
347 for (unsigned i = 0; i != NumModuleTypes; ++i) {
348 // Size of plane before function came
349 unsigned ModuleLev = getModuleLevel(i);
350 assert(int(ModuleLev) >= 0 && "BAD!");
352 TypePlane &Plane = getPlane(i);
354 assert(ModuleLev <= Plane.size() && "module levels higher than elements?");
355 while (Plane.size() != ModuleLev) {
356 assert(!isa<GlobalValue>(Plane.back()) &&
357 "Functions cannot define globals!");
358 NodeMap.erase(Plane.back()); // Erase from nodemap
359 Plane.pop_back(); // Shrink plane
363 // We don't need this state anymore, free it up.
367 // Finally, remove any type planes defined by the function...
368 CompactionTypes.clear();
369 if (!CompactionTable.empty()) {
370 CompactionTable.clear();
372 while (Table.size() > NumModuleTypes) {
373 TypePlane &Plane = Table.back();
374 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
375 << Plane.size() << "\n");
376 while (Plane.size()) {
377 assert(!isa<GlobalValue>(Plane.back()) &&
378 "Functions cannot define globals!");
379 NodeMap.erase(Plane.back()); // Erase from nodemap
380 Plane.pop_back(); // Shrink plane
383 Table.pop_back(); // Nuke the plane, we don't like it.
387 SC_DEBUG("end purgeFunction!\n");
390 static inline bool hasNullValue(unsigned TyID) {
391 return TyID != Type::LabelTyID && TyID != Type::VoidTyID;
394 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
395 /// approximation of the compaction table.
396 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Value *V) {
397 std::map<const Value*, unsigned>::iterator I =
398 CompactionNodeMap.lower_bound(V);
399 if (I != CompactionNodeMap.end() && I->first == V)
400 return I->second; // Already exists?
402 // Make sure the type is in the table.
404 if (!CompactionTypes.empty())
405 Ty = getOrCreateCompactionTableSlot(V->getType());
406 else // If the type plane was decompactified, use the global plane ID
407 Ty = getSlot(V->getType());
408 if (CompactionTable.size() <= Ty)
409 CompactionTable.resize(Ty+1);
411 TypePlane &TyPlane = CompactionTable[Ty];
413 // Make sure to insert the null entry if the thing we are inserting is not a
415 if (TyPlane.empty() && hasNullValue(V->getType()->getTypeID())) {
416 Value *ZeroInitializer = Constant::getNullValue(V->getType());
417 if (V != ZeroInitializer) {
418 TyPlane.push_back(ZeroInitializer);
419 CompactionNodeMap[ZeroInitializer] = 0;
423 unsigned SlotNo = TyPlane.size();
424 TyPlane.push_back(V);
425 CompactionNodeMap.insert(std::make_pair(V, SlotNo));
429 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
430 /// approximation of the compaction table.
431 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Type *T) {
432 std::map<const Type*, unsigned>::iterator I =
433 CompactionTypeMap.lower_bound(T);
434 if (I != CompactionTypeMap.end() && I->first == T)
435 return I->second; // Already exists?
437 unsigned SlotNo = CompactionTypes.size();
438 SC_DEBUG("Inserting Compaction Type #" << SlotNo << ": " << T << "\n");
439 CompactionTypes.push_back(T);
440 CompactionTypeMap.insert(std::make_pair(T, SlotNo));
444 /// buildCompactionTable - Since all of the function constants and types are
445 /// stored in the module-level constant table, we don't need to emit a function
446 /// constant table. Also due to this, the indices for various constants and
447 /// types might be very large in large programs. In order to avoid blowing up
448 /// the size of instructions in the bytecode encoding, we build a compaction
449 /// table, which defines a mapping from function-local identifiers to global
451 void SlotCalculator::buildCompactionTable(const Function *F) {
452 assert(CompactionNodeMap.empty() && "Compaction table already built!");
453 assert(CompactionTypeMap.empty() && "Compaction types already built!");
454 // First step, insert the primitive types.
455 CompactionTable.resize(Type::LastPrimitiveTyID+1);
456 for (unsigned i = 0; i <= Type::LastPrimitiveTyID; ++i) {
457 const Type *PrimTy = Type::getPrimitiveType((Type::TypeID)i);
458 CompactionTypes.push_back(PrimTy);
459 CompactionTypeMap[PrimTy] = i;
462 // Next, include any types used by function arguments.
463 for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
464 getOrCreateCompactionTableSlot(I->getType());
466 // Next, find all of the types and values that are referred to by the
467 // instructions in the function.
468 for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
469 getOrCreateCompactionTableSlot(I->getType());
470 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
471 if (isa<Constant>(I->getOperand(op)))
472 getOrCreateCompactionTableSlot(I->getOperand(op));
473 if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I))
474 getOrCreateCompactionTableSlot(VAN->getArgType());
477 // Do the types in the symbol table
478 const SymbolTable &ST = F->getSymbolTable();
479 for (SymbolTable::type_const_iterator TI = ST.type_begin(),
480 TE = ST.type_end(); TI != TE; ++TI)
481 getOrCreateCompactionTableSlot(TI->second);
483 // Now do the constants and global values
484 for (SymbolTable::plane_const_iterator PI = ST.plane_begin(),
485 PE = ST.plane_end(); PI != PE; ++PI)
486 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
487 VE = PI->second.end(); VI != VE; ++VI)
488 if (isa<Constant>(VI->second) && !isa<GlobalValue>(VI->second))
489 getOrCreateCompactionTableSlot(VI->second);
491 // Now that we have all of the values in the table, and know what types are
492 // referenced, make sure that there is at least the zero initializer in any
493 // used type plane. Since the type was used, we will be emitting instructions
494 // to the plane even if there are no constants in it.
495 CompactionTable.resize(CompactionTypes.size());
496 for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i)
497 if (CompactionTable[i].empty() && (i != Type::VoidTyID) &&
498 i != Type::LabelTyID) {
499 const Type *Ty = CompactionTypes[i];
500 SC_DEBUG("Getting Null Value #" << i << " for Type " << Ty << "\n");
501 assert(Ty->getTypeID() != Type::VoidTyID);
502 assert(Ty->getTypeID() != Type::LabelTyID);
503 getOrCreateCompactionTableSlot(Constant::getNullValue(Ty));
506 // Okay, now at this point, we have a legal compaction table. Since we want
507 // to emit the smallest possible binaries, do not compactify the type plane if
508 // it will not save us anything. Because we have not yet incorporated the
509 // function body itself yet, we don't know whether or not it's a good idea to
510 // compactify other planes. We will defer this decision until later.
511 TypeList &GlobalTypes = Types;
513 // All of the values types will be scrunched to the start of the types plane
514 // of the global table. Figure out just how many there are.
515 assert(!GlobalTypes.empty() && "No global types???");
516 unsigned NumFCTypes = GlobalTypes.size()-1;
517 while (!GlobalTypes[NumFCTypes]->isFirstClassType())
520 // If there are fewer that 64 types, no instructions will be exploded due to
521 // the size of the type operands. Thus there is no need to compactify types.
522 // Also, if the compaction table contains most of the entries in the global
523 // table, there really is no reason to compactify either.
524 if (NumFCTypes < 64) {
525 // Decompactifying types is tricky, because we have to move type planes all
526 // over the place. At least we don't need to worry about updating the
527 // CompactionNodeMap for non-types though.
528 std::vector<TypePlane> TmpCompactionTable;
529 std::swap(CompactionTable, TmpCompactionTable);
531 std::swap(TmpTypes, CompactionTypes);
533 // Move each plane back over to the uncompactified plane
534 while (!TmpTypes.empty()) {
535 const Type *Ty = TmpTypes.back();
537 CompactionTypeMap.erase(Ty); // Decompactify type!
539 // Find the global slot number for this type.
540 int TySlot = getSlot(Ty);
541 assert(TySlot != -1 && "Type doesn't exist in global table?");
543 // Now we know where to put the compaction table plane.
544 if (CompactionTable.size() <= unsigned(TySlot))
545 CompactionTable.resize(TySlot+1);
546 // Move the plane back into the compaction table.
547 std::swap(CompactionTable[TySlot], TmpCompactionTable[TmpTypes.size()]);
549 // And remove the empty plane we just moved in.
550 TmpCompactionTable.pop_back();
556 /// pruneCompactionTable - Once the entire function being processed has been
557 /// incorporated into the current compaction table, look over the compaction
558 /// table and check to see if there are any values whose compaction will not
559 /// save us any space in the bytecode file. If compactifying these values
560 /// serves no purpose, then we might as well not even emit the compactification
561 /// information to the bytecode file, saving a bit more space.
563 /// Note that the type plane has already been compactified if possible.
565 void SlotCalculator::pruneCompactionTable() {
566 TypeList &TyPlane = CompactionTypes;
567 for (unsigned ctp = 0, e = CompactionTable.size(); ctp != e; ++ctp)
568 if (!CompactionTable[ctp].empty()) {
569 TypePlane &CPlane = CompactionTable[ctp];
570 unsigned GlobalSlot = ctp;
571 if (!TyPlane.empty())
572 GlobalSlot = getGlobalSlot(TyPlane[ctp]);
574 if (GlobalSlot >= Table.size())
575 Table.resize(GlobalSlot+1);
576 TypePlane &GPlane = Table[GlobalSlot];
578 unsigned ModLevel = getModuleLevel(ctp);
579 unsigned NumFunctionObjs = CPlane.size()-ModLevel;
581 // If the maximum index required if all entries in this plane were merged
582 // into the global plane is less than 64, go ahead and eliminate the
584 bool PrunePlane = GPlane.size() + NumFunctionObjs < 64;
586 // If there are no function-local values defined, and the maximum
587 // referenced global entry is less than 64, we don't need to compactify.
588 if (!PrunePlane && NumFunctionObjs == 0) {
590 for (unsigned i = 0; i != ModLevel; ++i) {
591 unsigned Idx = NodeMap[CPlane[i]];
592 if (Idx > MaxIdx) MaxIdx = Idx;
594 PrunePlane = MaxIdx < 64;
597 // Ok, finally, if we decided to prune this plane out of the compaction
601 std::swap(OldPlane, CPlane);
603 // Loop over the function local objects, relocating them to the global
605 for (unsigned i = ModLevel, e = OldPlane.size(); i != e; ++i) {
606 const Value *V = OldPlane[i];
607 CompactionNodeMap.erase(V);
608 assert(NodeMap.count(V) == 0 && "Value already in table??");
612 // For compactified global values, just remove them from the compaction
614 for (unsigned i = 0; i != ModLevel; ++i)
615 CompactionNodeMap.erase(OldPlane[i]);
617 // Update the new modulelevel for this plane.
618 assert(ctp < ModuleLevel.size() && "Cannot set modulelevel!");
619 ModuleLevel[ctp] = GPlane.size()-NumFunctionObjs;
620 assert((int)ModuleLevel[ctp] >= 0 && "Bad computation!");
625 /// Determine if the compaction table is actually empty. Because the
626 /// compaction table always includes the primitive type planes, we
627 /// can't just check getCompactionTable().size() because it will never
628 /// be zero. Furthermore, the ModuleLevel factors into whether a given
629 /// plane is empty or not. This function does the necessary computation
630 /// to determine if its actually empty.
631 bool SlotCalculator::CompactionTableIsEmpty() const {
632 // Check a degenerate case, just in case.
633 if (CompactionTable.size() == 0) return true;
636 for (unsigned i = 0, e = CompactionTable.size(); i < e; ++i) {
637 // If the plane is not empty
638 if (!CompactionTable[i].empty()) {
639 // If the module level is non-zero then at least the
640 // first element of the plane is valid and therefore not empty.
641 unsigned End = getModuleLevel(i);
646 // All the compaction table planes are empty so the table is
647 // considered empty too.
651 int SlotCalculator::getSlot(const Value *V) const {
652 // If there is a CompactionTable active...
653 if (!CompactionNodeMap.empty()) {
654 std::map<const Value*, unsigned>::const_iterator I =
655 CompactionNodeMap.find(V);
656 if (I != CompactionNodeMap.end())
657 return (int)I->second;
658 // Otherwise, if it's not in the compaction table, it must be in a
659 // non-compactified plane.
662 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
663 if (I != NodeMap.end())
664 return (int)I->second;
669 int SlotCalculator::getSlot(const Type*T) const {
670 // If there is a CompactionTable active...
671 if (!CompactionTypeMap.empty()) {
672 std::map<const Type*, unsigned>::const_iterator I =
673 CompactionTypeMap.find(T);
674 if (I != CompactionTypeMap.end())
675 return (int)I->second;
676 // Otherwise, if it's not in the compaction table, it must be in a
677 // non-compactified plane.
680 std::map<const Type*, unsigned>::const_iterator I = TypeMap.find(T);
681 if (I != TypeMap.end())
682 return (int)I->second;
687 int SlotCalculator::getOrCreateSlot(const Value *V) {
688 if (V->getType() == Type::VoidTy) return -1;
690 int SlotNo = getSlot(V); // Check to see if it's already in!
691 if (SlotNo != -1) return SlotNo;
693 if (!isa<GlobalValue>(V)) // Initializers for globals are handled explicitly
694 if (const Constant *C = dyn_cast<Constant>(V)) {
695 assert(CompactionNodeMap.empty() &&
696 "All needed constants should be in the compaction map already!");
698 // Do not index the characters that make up constant strings. We emit
699 // constant strings as special entities that don't require their
700 // individual characters to be emitted.
701 if (!isa<ConstantArray>(C) || !cast<ConstantArray>(C)->isString()) {
702 // This makes sure that if a constant has uses (for example an array of
703 // const ints), that they are inserted also.
705 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
709 assert(ModuleLevel.empty() &&
710 "How can a constant string be directly accessed in a function?");
711 // Otherwise, if we are emitting a bytecode file and this IS a string,
713 if (!C->isNullValue())
714 ConstantStrings.push_back(cast<ConstantArray>(C));
718 return insertValue(V);
721 int SlotCalculator::getOrCreateSlot(const Type* T) {
722 int SlotNo = getSlot(T); // Check to see if it's already in!
723 if (SlotNo != -1) return SlotNo;
724 return insertType(T);
727 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
728 assert(D && "Can't insert a null value!");
729 assert(getSlot(D) == -1 && "Value is already in the table!");
731 // If we are building a compaction map, and if this plane is being compacted,
732 // insert the value into the compaction map, not into the global map.
733 if (!CompactionNodeMap.empty()) {
734 if (D->getType() == Type::VoidTy) return -1; // Do not insert void values
735 assert(!isa<Constant>(D) &&
736 "Types, constants, and globals should be in global table!");
738 int Plane = getSlot(D->getType());
739 assert(Plane != -1 && CompactionTable.size() > (unsigned)Plane &&
740 "Didn't find value type!");
741 if (!CompactionTable[Plane].empty())
742 return getOrCreateCompactionTableSlot(D);
745 // If this node does not contribute to a plane, or if the node has a
746 // name and we don't want names, then ignore the silly node... Note that types
747 // do need slot numbers so that we can keep track of where other values land.
749 if (!dontIgnore) // Don't ignore nonignorables!
750 if (D->getType() == Type::VoidTy ) { // Ignore void type nodes
751 SC_DEBUG("ignored value " << *D << "\n");
752 return -1; // We do need types unconditionally though
755 // Okay, everything is happy, actually insert the silly value now...
756 return doInsertValue(D);
759 int SlotCalculator::insertType(const Type *Ty, bool dontIgnore) {
760 assert(Ty && "Can't insert a null type!");
761 assert(getSlot(Ty) == -1 && "Type is already in the table!");
763 // If we are building a compaction map, and if this plane is being compacted,
764 // insert the value into the compaction map, not into the global map.
765 if (!CompactionTypeMap.empty()) {
766 getOrCreateCompactionTableSlot(Ty);
769 // Insert the current type before any subtypes. This is important because
770 // recursive types elements are inserted in a bottom up order. Changing
771 // this here can break things. For example:
773 // global { \2 * } { { \2 }* null }
775 int ResultSlot = doInsertType(Ty);
776 SC_DEBUG(" Inserted type: " << Ty->getDescription() << " slot=" <<
779 // Loop over any contained types in the definition... in post
781 for (po_iterator<const Type*> I = po_begin(Ty), E = po_end(Ty);
784 const Type *SubTy = *I;
785 // If we haven't seen this sub type before, add it to our type table!
786 if (getSlot(SubTy) == -1) {
787 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
789 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() << "\n");
796 // doInsertValue - This is a small helper function to be called only
799 int SlotCalculator::doInsertValue(const Value *D) {
800 const Type *Typ = D->getType();
803 // Used for debugging DefSlot=-1 assertion...
804 //if (Typ == Type::TypeTy)
805 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
807 if (Typ->isDerivedType()) {
809 if (CompactionTable.empty())
810 ValSlot = getSlot(Typ);
812 ValSlot = getGlobalSlot(Typ);
813 if (ValSlot == -1) { // Have we already entered this type?
814 // Nope, this is the first we have seen the type, process it.
815 ValSlot = insertType(Typ, true);
816 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
818 Ty = (unsigned)ValSlot;
820 Ty = Typ->getTypeID();
823 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
824 Table.resize(Ty+1, TypePlane());
826 // If this is the first value to get inserted into the type plane, make sure
827 // to insert the implicit null value...
828 if (Table[Ty].empty() && hasNullValue(Ty)) {
829 Value *ZeroInitializer = Constant::getNullValue(Typ);
831 // If we are pushing zeroinit, it will be handled below.
832 if (D != ZeroInitializer) {
833 Table[Ty].push_back(ZeroInitializer);
834 NodeMap[ZeroInitializer] = 0;
838 // Insert node into table and NodeMap...
839 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
840 Table[Ty].push_back(D);
842 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
844 // G = Global, C = Constant, T = Type, F = Function, o = other
845 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
846 (isa<Function>(D) ? "F" : "o"))));
848 return (int)DestSlot;
851 // doInsertType - This is a small helper function to be called only
854 int SlotCalculator::doInsertType(const Type *Ty) {
856 // Insert node into table and NodeMap...
857 unsigned DestSlot = TypeMap[Ty] = Types.size();
860 SC_DEBUG(" Inserting type [" << DestSlot << "] = " << Ty << "\n" );
861 return (int)DestSlot;