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/InlineAsm.h"
22 #include "llvm/Instructions.h"
23 #include "llvm/Module.h"
24 #include "llvm/SymbolTable.h"
25 #include "llvm/Type.h"
26 #include "llvm/Analysis/ConstantsScanner.h"
27 #include "llvm/ADT/PostOrderIterator.h"
28 #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_global_iterator I = TheModule->global_begin(),
125 E = TheModule->global_end(); I != E; ++I)
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_global_iterator I = TheModule->global_begin(),
138 E = TheModule->global_end(); I != E; ++I)
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 (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
187 if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
189 getOrCreateSlot(*OI);
191 getOrCreateSlot(I->getType());
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_arg_iterator I = F->arg_begin(), E = F->arg_end(); 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 for (constant_iterator CI = constant_begin(F), CE = constant_end(F);
302 getOrCreateSlot(*CI);
304 // If there is a symbol table, it is possible that the user has names for
305 // constants that are not being used. In this case, we will have problems
306 // if we don't emit the constants now, because otherwise we will get
307 // symbol table references to constants not in the output. Scan for these
310 processSymbolTableConstants(&F->getSymbolTable());
313 SC_DEBUG("Inserting Instructions:\n");
315 // Add all of the instructions to the type planes...
316 for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
318 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
323 // If we are building a compaction table, prune out planes that do not benefit
324 // from being compactified.
325 if (!CompactionTable.empty())
326 pruneCompactionTable();
328 SC_DEBUG("end processFunction!\n");
331 void SlotCalculator::purgeFunction() {
332 assert((ModuleLevel.size() != 0 ||
333 ModuleTypeLevel != 0) && "Module not incorporated!");
334 unsigned NumModuleTypes = ModuleLevel.size();
336 SC_DEBUG("begin purgeFunction!\n");
338 // First, free the compaction map if used.
339 CompactionNodeMap.clear();
340 CompactionTypeMap.clear();
342 // Next, remove values from existing type planes
343 for (unsigned i = 0; i != NumModuleTypes; ++i) {
344 // Size of plane before function came
345 unsigned ModuleLev = getModuleLevel(i);
346 assert(int(ModuleLev) >= 0 && "BAD!");
348 TypePlane &Plane = getPlane(i);
350 assert(ModuleLev <= Plane.size() && "module levels higher than elements?");
351 while (Plane.size() != ModuleLev) {
352 assert(!isa<GlobalValue>(Plane.back()) &&
353 "Functions cannot define globals!");
354 NodeMap.erase(Plane.back()); // Erase from nodemap
355 Plane.pop_back(); // Shrink plane
359 // We don't need this state anymore, free it up.
363 // Finally, remove any type planes defined by the function...
364 CompactionTypes.clear();
365 if (!CompactionTable.empty()) {
366 CompactionTable.clear();
368 while (Table.size() > NumModuleTypes) {
369 TypePlane &Plane = Table.back();
370 SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
371 << Plane.size() << "\n");
372 while (Plane.size()) {
373 assert(!isa<GlobalValue>(Plane.back()) &&
374 "Functions cannot define globals!");
375 NodeMap.erase(Plane.back()); // Erase from nodemap
376 Plane.pop_back(); // Shrink plane
379 Table.pop_back(); // Nuke the plane, we don't like it.
383 SC_DEBUG("end purgeFunction!\n");
386 static inline bool hasNullValue(const Type *Ty) {
387 return Ty != Type::LabelTy && Ty != Type::VoidTy && !isa<OpaqueType>(Ty);
390 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
391 /// approximation of the compaction table.
392 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Value *V) {
393 std::map<const Value*, unsigned>::iterator I =
394 CompactionNodeMap.lower_bound(V);
395 if (I != CompactionNodeMap.end() && I->first == V)
396 return I->second; // Already exists?
398 // Make sure the type is in the table.
400 if (!CompactionTypes.empty())
401 Ty = getOrCreateCompactionTableSlot(V->getType());
402 else // If the type plane was decompactified, use the global plane ID
403 Ty = getSlot(V->getType());
404 if (CompactionTable.size() <= Ty)
405 CompactionTable.resize(Ty+1);
407 TypePlane &TyPlane = CompactionTable[Ty];
409 // Make sure to insert the null entry if the thing we are inserting is not a
411 if (TyPlane.empty() && hasNullValue(V->getType())) {
412 Value *ZeroInitializer = Constant::getNullValue(V->getType());
413 if (V != ZeroInitializer) {
414 TyPlane.push_back(ZeroInitializer);
415 CompactionNodeMap[ZeroInitializer] = 0;
419 unsigned SlotNo = TyPlane.size();
420 TyPlane.push_back(V);
421 CompactionNodeMap.insert(std::make_pair(V, SlotNo));
425 /// getOrCreateCompactionTableSlot - This method is used to build up the initial
426 /// approximation of the compaction table.
427 unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Type *T) {
428 std::map<const Type*, unsigned>::iterator I =
429 CompactionTypeMap.lower_bound(T);
430 if (I != CompactionTypeMap.end() && I->first == T)
431 return I->second; // Already exists?
433 unsigned SlotNo = CompactionTypes.size();
434 SC_DEBUG("Inserting Compaction Type #" << SlotNo << ": " << T << "\n");
435 CompactionTypes.push_back(T);
436 CompactionTypeMap.insert(std::make_pair(T, SlotNo));
440 /// buildCompactionTable - Since all of the function constants and types are
441 /// stored in the module-level constant table, we don't need to emit a function
442 /// constant table. Also due to this, the indices for various constants and
443 /// types might be very large in large programs. In order to avoid blowing up
444 /// the size of instructions in the bytecode encoding, we build a compaction
445 /// table, which defines a mapping from function-local identifiers to global
447 void SlotCalculator::buildCompactionTable(const Function *F) {
448 assert(CompactionNodeMap.empty() && "Compaction table already built!");
449 assert(CompactionTypeMap.empty() && "Compaction types already built!");
450 // First step, insert the primitive types.
451 CompactionTable.resize(Type::LastPrimitiveTyID+1);
452 for (unsigned i = 0; i <= Type::LastPrimitiveTyID; ++i) {
453 const Type *PrimTy = Type::getPrimitiveType((Type::TypeID)i);
454 CompactionTypes.push_back(PrimTy);
455 CompactionTypeMap[PrimTy] = i;
458 // Next, include any types used by function arguments.
459 for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
461 getOrCreateCompactionTableSlot(I->getType());
463 // Next, find all of the types and values that are referred to by the
464 // instructions in the function.
465 for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
466 getOrCreateCompactionTableSlot(I->getType());
467 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
468 if (isa<Constant>(I->getOperand(op)) || isa<InlineAsm>(I->getOperand(op)))
469 getOrCreateCompactionTableSlot(I->getOperand(op));
472 // Do the types in the symbol table
473 const SymbolTable &ST = F->getSymbolTable();
474 for (SymbolTable::type_const_iterator TI = ST.type_begin(),
475 TE = ST.type_end(); TI != TE; ++TI)
476 getOrCreateCompactionTableSlot(TI->second);
478 // Now do the constants and global values
479 for (SymbolTable::plane_const_iterator PI = ST.plane_begin(),
480 PE = ST.plane_end(); PI != PE; ++PI)
481 for (SymbolTable::value_const_iterator VI = PI->second.begin(),
482 VE = PI->second.end(); VI != VE; ++VI)
483 if (isa<Constant>(VI->second) && !isa<GlobalValue>(VI->second))
484 getOrCreateCompactionTableSlot(VI->second);
486 // Now that we have all of the values in the table, and know what types are
487 // referenced, make sure that there is at least the zero initializer in any
488 // used type plane. Since the type was used, we will be emitting instructions
489 // to the plane even if there are no constants in it.
490 CompactionTable.resize(CompactionTypes.size());
491 for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i)
492 if (CompactionTable[i].empty() && (i != Type::VoidTyID) &&
493 i != Type::LabelTyID) {
494 const Type *Ty = CompactionTypes[i];
495 SC_DEBUG("Getting Null Value #" << i << " for Type " << Ty << "\n");
496 assert(Ty->getTypeID() != Type::VoidTyID);
497 assert(Ty->getTypeID() != Type::LabelTyID);
498 getOrCreateCompactionTableSlot(Constant::getNullValue(Ty));
501 // Okay, now at this point, we have a legal compaction table. Since we want
502 // to emit the smallest possible binaries, do not compactify the type plane if
503 // it will not save us anything. Because we have not yet incorporated the
504 // function body itself yet, we don't know whether or not it's a good idea to
505 // compactify other planes. We will defer this decision until later.
506 TypeList &GlobalTypes = Types;
508 // All of the values types will be scrunched to the start of the types plane
509 // of the global table. Figure out just how many there are.
510 assert(!GlobalTypes.empty() && "No global types???");
511 unsigned NumFCTypes = GlobalTypes.size()-1;
512 while (!GlobalTypes[NumFCTypes]->isFirstClassType())
515 // If there are fewer that 64 types, no instructions will be exploded due to
516 // the size of the type operands. Thus there is no need to compactify types.
517 // Also, if the compaction table contains most of the entries in the global
518 // table, there really is no reason to compactify either.
519 if (NumFCTypes < 64) {
520 // Decompactifying types is tricky, because we have to move type planes all
521 // over the place. At least we don't need to worry about updating the
522 // CompactionNodeMap for non-types though.
523 std::vector<TypePlane> TmpCompactionTable;
524 std::swap(CompactionTable, TmpCompactionTable);
526 std::swap(TmpTypes, CompactionTypes);
528 // Move each plane back over to the uncompactified plane
529 while (!TmpTypes.empty()) {
530 const Type *Ty = TmpTypes.back();
532 CompactionTypeMap.erase(Ty); // Decompactify type!
534 // Find the global slot number for this type.
535 int TySlot = getSlot(Ty);
536 assert(TySlot != -1 && "Type doesn't exist in global table?");
538 // Now we know where to put the compaction table plane.
539 if (CompactionTable.size() <= unsigned(TySlot))
540 CompactionTable.resize(TySlot+1);
541 // Move the plane back into the compaction table.
542 std::swap(CompactionTable[TySlot], TmpCompactionTable[TmpTypes.size()]);
544 // And remove the empty plane we just moved in.
545 TmpCompactionTable.pop_back();
551 /// pruneCompactionTable - Once the entire function being processed has been
552 /// incorporated into the current compaction table, look over the compaction
553 /// table and check to see if there are any values whose compaction will not
554 /// save us any space in the bytecode file. If compactifying these values
555 /// serves no purpose, then we might as well not even emit the compactification
556 /// information to the bytecode file, saving a bit more space.
558 /// Note that the type plane has already been compactified if possible.
560 void SlotCalculator::pruneCompactionTable() {
561 TypeList &TyPlane = CompactionTypes;
562 for (unsigned ctp = 0, e = CompactionTable.size(); ctp != e; ++ctp)
563 if (!CompactionTable[ctp].empty()) {
564 TypePlane &CPlane = CompactionTable[ctp];
565 unsigned GlobalSlot = ctp;
566 if (!TyPlane.empty())
567 GlobalSlot = getGlobalSlot(TyPlane[ctp]);
569 if (GlobalSlot >= Table.size())
570 Table.resize(GlobalSlot+1);
571 TypePlane &GPlane = Table[GlobalSlot];
573 unsigned ModLevel = getModuleLevel(ctp);
574 unsigned NumFunctionObjs = CPlane.size()-ModLevel;
576 // If the maximum index required if all entries in this plane were merged
577 // into the global plane is less than 64, go ahead and eliminate the
579 bool PrunePlane = GPlane.size() + NumFunctionObjs < 64;
581 // If there are no function-local values defined, and the maximum
582 // referenced global entry is less than 64, we don't need to compactify.
583 if (!PrunePlane && NumFunctionObjs == 0) {
585 for (unsigned i = 0; i != ModLevel; ++i) {
586 unsigned Idx = NodeMap[CPlane[i]];
587 if (Idx > MaxIdx) MaxIdx = Idx;
589 PrunePlane = MaxIdx < 64;
592 // Ok, finally, if we decided to prune this plane out of the compaction
596 std::swap(OldPlane, CPlane);
598 // Loop over the function local objects, relocating them to the global
600 for (unsigned i = ModLevel, e = OldPlane.size(); i != e; ++i) {
601 const Value *V = OldPlane[i];
602 CompactionNodeMap.erase(V);
603 assert(NodeMap.count(V) == 0 && "Value already in table??");
607 // For compactified global values, just remove them from the compaction
609 for (unsigned i = 0; i != ModLevel; ++i)
610 CompactionNodeMap.erase(OldPlane[i]);
612 // Update the new modulelevel for this plane.
613 assert(ctp < ModuleLevel.size() && "Cannot set modulelevel!");
614 ModuleLevel[ctp] = GPlane.size()-NumFunctionObjs;
615 assert((int)ModuleLevel[ctp] >= 0 && "Bad computation!");
620 /// Determine if the compaction table is actually empty. Because the
621 /// compaction table always includes the primitive type planes, we
622 /// can't just check getCompactionTable().size() because it will never
623 /// be zero. Furthermore, the ModuleLevel factors into whether a given
624 /// plane is empty or not. This function does the necessary computation
625 /// to determine if its actually empty.
626 bool SlotCalculator::CompactionTableIsEmpty() const {
627 // Check a degenerate case, just in case.
628 if (CompactionTable.size() == 0) return true;
631 for (unsigned i = 0, e = CompactionTable.size(); i < e; ++i) {
632 // If the plane is not empty
633 if (!CompactionTable[i].empty()) {
634 // If the module level is non-zero then at least the
635 // first element of the plane is valid and therefore not empty.
636 unsigned End = getModuleLevel(i);
641 // All the compaction table planes are empty so the table is
642 // considered empty too.
646 int SlotCalculator::getSlot(const Value *V) const {
647 // If there is a CompactionTable active...
648 if (!CompactionNodeMap.empty()) {
649 std::map<const Value*, unsigned>::const_iterator I =
650 CompactionNodeMap.find(V);
651 if (I != CompactionNodeMap.end())
652 return (int)I->second;
653 // Otherwise, if it's not in the compaction table, it must be in a
654 // non-compactified plane.
657 std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
658 if (I != NodeMap.end())
659 return (int)I->second;
664 int SlotCalculator::getSlot(const Type*T) const {
665 // If there is a CompactionTable active...
666 if (!CompactionTypeMap.empty()) {
667 std::map<const Type*, unsigned>::const_iterator I =
668 CompactionTypeMap.find(T);
669 if (I != CompactionTypeMap.end())
670 return (int)I->second;
671 // Otherwise, if it's not in the compaction table, it must be in a
672 // non-compactified plane.
675 std::map<const Type*, unsigned>::const_iterator I = TypeMap.find(T);
676 if (I != TypeMap.end())
677 return (int)I->second;
682 int SlotCalculator::getOrCreateSlot(const Value *V) {
683 if (V->getType() == Type::VoidTy) return -1;
685 int SlotNo = getSlot(V); // Check to see if it's already in!
686 if (SlotNo != -1) return SlotNo;
688 if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
689 assert(GV->getParent() != 0 && "Global not embedded into a module!");
691 if (!isa<GlobalValue>(V)) // Initializers for globals are handled explicitly
692 if (const Constant *C = dyn_cast<Constant>(V)) {
693 assert(CompactionNodeMap.empty() &&
694 "All needed constants should be in the compaction map already!");
696 // Do not index the characters that make up constant strings. We emit
697 // constant strings as special entities that don't require their
698 // individual characters to be emitted.
699 if (!isa<ConstantArray>(C) || !cast<ConstantArray>(C)->isString()) {
700 // This makes sure that if a constant has uses (for example an array of
701 // const ints), that they are inserted also.
703 for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
707 assert(ModuleLevel.empty() &&
708 "How can a constant string be directly accessed in a function?");
709 // Otherwise, if we are emitting a bytecode file and this IS a string,
711 if (!C->isNullValue())
712 ConstantStrings.push_back(cast<ConstantArray>(C));
716 return insertValue(V);
719 int SlotCalculator::getOrCreateSlot(const Type* T) {
720 int SlotNo = getSlot(T); // Check to see if it's already in!
721 if (SlotNo != -1) return SlotNo;
722 return insertType(T);
725 int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
726 assert(D && "Can't insert a null value!");
727 assert(getSlot(D) == -1 && "Value is already in the table!");
729 // If we are building a compaction map, and if this plane is being compacted,
730 // insert the value into the compaction map, not into the global map.
731 if (!CompactionNodeMap.empty()) {
732 if (D->getType() == Type::VoidTy) return -1; // Do not insert void values
733 assert(!isa<Constant>(D) &&
734 "Types, constants, and globals should be in global table!");
736 int Plane = getSlot(D->getType());
737 assert(Plane != -1 && CompactionTable.size() > (unsigned)Plane &&
738 "Didn't find value type!");
739 if (!CompactionTable[Plane].empty())
740 return getOrCreateCompactionTableSlot(D);
743 // If this node does not contribute to a plane, or if the node has a
744 // name and we don't want names, then ignore the silly node... Note that types
745 // do need slot numbers so that we can keep track of where other values land.
747 if (!dontIgnore) // Don't ignore nonignorables!
748 if (D->getType() == Type::VoidTy ) { // Ignore void type nodes
749 SC_DEBUG("ignored value " << *D << "\n");
750 return -1; // We do need types unconditionally though
753 // Okay, everything is happy, actually insert the silly value now...
754 return doInsertValue(D);
757 int SlotCalculator::insertType(const Type *Ty, bool dontIgnore) {
758 assert(Ty && "Can't insert a null type!");
759 assert(getSlot(Ty) == -1 && "Type is already in the table!");
761 // If we are building a compaction map, and if this plane is being compacted,
762 // insert the value into the compaction map, not into the global map.
763 if (!CompactionTypeMap.empty()) {
764 getOrCreateCompactionTableSlot(Ty);
767 // Insert the current type before any subtypes. This is important because
768 // recursive types elements are inserted in a bottom up order. Changing
769 // this here can break things. For example:
771 // global { \2 * } { { \2 }* null }
773 int ResultSlot = doInsertType(Ty);
774 SC_DEBUG(" Inserted type: " << Ty->getDescription() << " slot=" <<
777 // Loop over any contained types in the definition... in post
779 for (po_iterator<const Type*> I = po_begin(Ty), E = po_end(Ty);
782 const Type *SubTy = *I;
783 // If we haven't seen this sub type before, add it to our type table!
784 if (getSlot(SubTy) == -1) {
785 SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
787 SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() << "\n");
794 // doInsertValue - This is a small helper function to be called only
797 int SlotCalculator::doInsertValue(const Value *D) {
798 const Type *Typ = D->getType();
801 // Used for debugging DefSlot=-1 assertion...
802 //if (Typ == Type::TypeTy)
803 // cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
805 if (Typ->isDerivedType()) {
807 if (CompactionTable.empty())
808 ValSlot = getSlot(Typ);
810 ValSlot = getGlobalSlot(Typ);
811 if (ValSlot == -1) { // Have we already entered this type?
812 // Nope, this is the first we have seen the type, process it.
813 ValSlot = insertType(Typ, true);
814 assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
816 Ty = (unsigned)ValSlot;
818 Ty = Typ->getTypeID();
821 if (Table.size() <= Ty) // Make sure we have the type plane allocated...
822 Table.resize(Ty+1, TypePlane());
824 // If this is the first value to get inserted into the type plane, make sure
825 // to insert the implicit null value...
826 if (Table[Ty].empty() && hasNullValue(Typ)) {
827 Value *ZeroInitializer = Constant::getNullValue(Typ);
829 // If we are pushing zeroinit, it will be handled below.
830 if (D != ZeroInitializer) {
831 Table[Ty].push_back(ZeroInitializer);
832 NodeMap[ZeroInitializer] = 0;
836 // Insert node into table and NodeMap...
837 unsigned DestSlot = NodeMap[D] = Table[Ty].size();
838 Table[Ty].push_back(D);
840 SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
842 // G = Global, C = Constant, T = Type, F = Function, o = other
843 SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
844 (isa<Function>(D) ? "F" : "o"))));
846 return (int)DestSlot;
849 // doInsertType - This is a small helper function to be called only
852 int SlotCalculator::doInsertType(const Type *Ty) {
854 // Insert node into table and NodeMap...
855 unsigned DestSlot = TypeMap[Ty] = Types.size();
858 SC_DEBUG(" Inserting type [" << DestSlot << "] = " << Ty << "\n" );
859 return (int)DestSlot;