1 //===- Local.cpp - Compute a local data structure graph for a function ----===//
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 // Compute the local version of the data structure graph for a function. The
11 // external interface to this file is the DSGraph constructor.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Analysis/DataStructure/DataStructure.h"
16 #include "llvm/Analysis/DataStructure/DSGraph.h"
17 #include "llvm/Constants.h"
18 #include "llvm/DerivedTypes.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/Intrinsics.h"
21 #include "llvm/Support/GetElementPtrTypeIterator.h"
22 #include "llvm/Support/InstVisitor.h"
23 #include "llvm/Target/TargetData.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/Timer.h"
29 // FIXME: This should eventually be a FunctionPass that is automatically
30 // aggregated into a Pass.
32 #include "llvm/Module.h"
36 static RegisterPass<LocalDataStructures>
37 X("datastructure", "Local Data Structure Analysis");
40 TrackIntegersAsPointers("dsa-track-integers", cl::Hidden,
41 cl::desc("If this is set, track integers as potential pointers"));
43 static cl::list<std::string>
44 AllocList("dsa-alloc-list",
45 cl::value_desc("list"),
46 cl::desc("List of functions that allocate memory from the heap"),
47 cl::CommaSeparated, cl::Hidden);
49 static cl::list<std::string>
50 FreeList("dsa-free-list",
51 cl::value_desc("list"),
52 cl::desc("List of functions that free memory from the heap"),
53 cl::CommaSeparated, cl::Hidden);
57 // isPointerType - Return true if this type is big enough to hold a pointer.
58 bool isPointerType(const Type *Ty) {
59 if (isa<PointerType>(Ty))
61 else if (TrackIntegersAsPointers && Ty->isPrimitiveType() &&Ty->isInteger())
62 return Ty->getPrimitiveSize() >= PointerSize;
71 DisableDirectCallOpt("disable-direct-call-dsopt", cl::Hidden,
72 cl::desc("Disable direct call optimization in "
73 "DSGraph construction"));
75 DisableFieldSensitivity("disable-ds-field-sensitivity", cl::Hidden,
76 cl::desc("Disable field sensitivity in DSGraphs"));
78 //===--------------------------------------------------------------------===//
80 //===--------------------------------------------------------------------===//
82 /// This class is the builder class that constructs the local data structure
83 /// graph by performing a single pass over the function in question.
85 class GraphBuilder : InstVisitor<GraphBuilder> {
87 DSNodeHandle *RetNode; // Node that gets returned...
88 DSScalarMap &ScalarMap;
89 std::list<DSCallSite> *FunctionCalls;
92 GraphBuilder(Function &f, DSGraph &g, DSNodeHandle &retNode,
93 std::list<DSCallSite> &fc)
94 : G(g), RetNode(&retNode), ScalarMap(G.getScalarMap()),
97 // Create scalar nodes for all pointer arguments...
98 for (Function::arg_iterator I = f.arg_begin(), E = f.arg_end();
100 if (isPointerType(I->getType()))
103 visit(f); // Single pass over the function
106 // GraphBuilder ctor for working on the globals graph
107 GraphBuilder(DSGraph &g)
108 : G(g), RetNode(0), ScalarMap(G.getScalarMap()), FunctionCalls(0) {
111 void mergeInGlobalInitializer(GlobalVariable *GV);
114 // Visitor functions, used to handle each instruction type we encounter...
115 friend class InstVisitor<GraphBuilder>;
116 void visitMallocInst(MallocInst &MI) { handleAlloc(MI, true); }
117 void visitAllocaInst(AllocaInst &AI) { handleAlloc(AI, false); }
118 void handleAlloc(AllocationInst &AI, bool isHeap);
120 void visitPHINode(PHINode &PN);
121 void visitSelectInst(SelectInst &SI);
123 void visitGetElementPtrInst(User &GEP);
124 void visitReturnInst(ReturnInst &RI);
125 void visitLoadInst(LoadInst &LI);
126 void visitStoreInst(StoreInst &SI);
127 void visitCallInst(CallInst &CI);
128 void visitInvokeInst(InvokeInst &II);
129 void visitSetCondInst(SetCondInst &SCI);
130 void visitFreeInst(FreeInst &FI);
131 void visitCastInst(CastInst &CI);
132 void visitInstruction(Instruction &I);
134 void visitCallSite(CallSite CS);
135 void visitVAArgInst(VAArgInst &I);
137 void MergeConstantInitIntoNode(DSNodeHandle &NH, Constant *C);
139 // Helper functions used to implement the visitation functions...
141 /// createNode - Create a new DSNode, ensuring that it is properly added to
144 DSNode *createNode(const Type *Ty = 0) {
145 DSNode *N = new DSNode(Ty, &G); // Create the node
146 if (DisableFieldSensitivity) {
147 // Create node handle referring to the old node so that it is
148 // immediately removed from the graph when the node handle is destroyed.
149 DSNodeHandle OldNNH = N;
150 N->foldNodeCompletely();
151 if (DSNode *FN = N->getForwardNode())
157 /// setDestTo - Set the ScalarMap entry for the specified value to point to
158 /// the specified destination. If the Value already points to a node, make
159 /// sure to merge the two destinations together.
161 void setDestTo(Value &V, const DSNodeHandle &NH);
163 /// getValueDest - Return the DSNode that the actual value points to.
165 DSNodeHandle getValueDest(Value &V);
167 /// getLink - This method is used to return the specified link in the
168 /// specified node if one exists. If a link does not already exist (it's
169 /// null), then we create a new node, link it, then return it.
171 DSNodeHandle &getLink(const DSNodeHandle &Node, unsigned Link = 0);
177 //===----------------------------------------------------------------------===//
178 // DSGraph constructor - Simply use the GraphBuilder to construct the local
180 DSGraph::DSGraph(EquivalenceClasses<GlobalValue*> &ECs, const TargetData &td,
181 Function &F, DSGraph *GG)
182 : GlobalsGraph(GG), ScalarMap(ECs), TD(td) {
183 PrintAuxCalls = false;
185 DEBUG(std::cerr << " [Loc] Calculating graph for: " << F.getName() << "\n");
187 // Use the graph builder to construct the local version of the graph
188 GraphBuilder B(F, *this, ReturnNodes[&F], FunctionCalls);
190 Timer::addPeakMemoryMeasurement();
193 // If there are any constant globals referenced in this function, merge their
194 // initializers into the local graph from the globals graph.
195 if (ScalarMap.global_begin() != ScalarMap.global_end()) {
196 ReachabilityCloner RC(*this, *GG, 0);
198 for (DSScalarMap::global_iterator I = ScalarMap.global_begin();
199 I != ScalarMap.global_end(); ++I)
200 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*I))
201 if (!GV->isExternal() && GV->isConstant())
202 RC.merge(ScalarMap[GV], GG->ScalarMap[GV]);
205 markIncompleteNodes(DSGraph::MarkFormalArgs);
207 // Remove any nodes made dead due to merging...
208 removeDeadNodes(DSGraph::KeepUnreachableGlobals);
212 //===----------------------------------------------------------------------===//
213 // Helper method implementations...
216 /// getValueDest - Return the DSNode that the actual value points to.
218 DSNodeHandle GraphBuilder::getValueDest(Value &Val) {
220 if (isa<Constant>(V) && cast<Constant>(V)->isNullValue())
221 return 0; // Null doesn't point to anything, don't add to ScalarMap!
223 DSNodeHandle &NH = ScalarMap[V];
225 return NH; // Already have a node? Just return it...
227 // Otherwise we need to create a new node to point to.
228 // Check first for constant expressions that must be traversed to
229 // extract the actual value.
231 if (GlobalValue* GV = dyn_cast<GlobalValue>(V)) {
232 // Create a new global node for this global variable.
233 N = createNode(GV->getType()->getElementType());
235 } else if (Constant *C = dyn_cast<Constant>(V)) {
236 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
237 if (CE->getOpcode() == Instruction::Cast) {
238 if (isa<PointerType>(CE->getOperand(0)->getType()))
239 NH = getValueDest(*CE->getOperand(0));
241 NH = createNode()->setUnknownNodeMarker();
242 } else if (CE->getOpcode() == Instruction::GetElementPtr) {
243 visitGetElementPtrInst(*CE);
244 DSScalarMap::iterator I = ScalarMap.find(CE);
245 assert(I != ScalarMap.end() && "GEP didn't get processed right?");
248 // This returns a conservative unknown node for any unhandled ConstExpr
249 return NH = createNode()->setUnknownNodeMarker();
251 if (NH.isNull()) { // (getelementptr null, X) returns null
256 } else if (isa<UndefValue>(C)) {
260 assert(0 && "Unknown constant type!");
262 N = createNode(); // just create a shadow node
264 // Otherwise just create a shadow node
268 NH.setTo(N, 0); // Remember that we are pointing to it...
273 /// getLink - This method is used to return the specified link in the
274 /// specified node if one exists. If a link does not already exist (it's
275 /// null), then we create a new node, link it, then return it. We must
276 /// specify the type of the Node field we are accessing so that we know what
277 /// type should be linked to if we need to create a new node.
279 DSNodeHandle &GraphBuilder::getLink(const DSNodeHandle &node, unsigned LinkNo) {
280 DSNodeHandle &Node = const_cast<DSNodeHandle&>(node);
281 DSNodeHandle &Link = Node.getLink(LinkNo);
283 // If the link hasn't been created yet, make and return a new shadow node
290 /// setDestTo - Set the ScalarMap entry for the specified value to point to the
291 /// specified destination. If the Value already points to a node, make sure to
292 /// merge the two destinations together.
294 void GraphBuilder::setDestTo(Value &V, const DSNodeHandle &NH) {
295 ScalarMap[&V].mergeWith(NH);
299 //===----------------------------------------------------------------------===//
300 // Specific instruction type handler implementations...
303 /// Alloca & Malloc instruction implementation - Simply create a new memory
304 /// object, pointing the scalar to it.
306 void GraphBuilder::handleAlloc(AllocationInst &AI, bool isHeap) {
307 DSNode *N = createNode();
309 N->setHeapNodeMarker();
311 N->setAllocaNodeMarker();
315 // PHINode - Make the scalar for the PHI node point to all of the things the
316 // incoming values point to... which effectively causes them to be merged.
318 void GraphBuilder::visitPHINode(PHINode &PN) {
319 if (!isPointerType(PN.getType())) return; // Only pointer PHIs
321 DSNodeHandle &PNDest = ScalarMap[&PN];
322 for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i)
323 PNDest.mergeWith(getValueDest(*PN.getIncomingValue(i)));
326 void GraphBuilder::visitSelectInst(SelectInst &SI) {
327 if (!isPointerType(SI.getType())) return; // Only pointer Selects
329 DSNodeHandle &Dest = ScalarMap[&SI];
330 Dest.mergeWith(getValueDest(*SI.getOperand(1)));
331 Dest.mergeWith(getValueDest(*SI.getOperand(2)));
334 void GraphBuilder::visitSetCondInst(SetCondInst &SCI) {
335 if (!isPointerType(SCI.getOperand(0)->getType()) ||
336 isa<ConstantPointerNull>(SCI.getOperand(1))) return; // Only pointers
337 ScalarMap[SCI.getOperand(0)].mergeWith(getValueDest(*SCI.getOperand(1)));
341 void GraphBuilder::visitGetElementPtrInst(User &GEP) {
342 DSNodeHandle Value = getValueDest(*GEP.getOperand(0));
344 Value = createNode();
346 // As a special case, if all of the index operands of GEP are constant zeros,
347 // handle this just like we handle casts (ie, don't do much).
348 bool AllZeros = true;
349 for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i)
350 if (GEP.getOperand(i) !=
351 Constant::getNullValue(GEP.getOperand(i)->getType())) {
356 // If all of the indices are zero, the result points to the operand without
357 // applying the type.
358 if (AllZeros || (!Value.isNull() &&
359 Value.getNode()->isNodeCompletelyFolded())) {
360 setDestTo(GEP, Value);
365 const PointerType *PTy = cast<PointerType>(GEP.getOperand(0)->getType());
366 const Type *CurTy = PTy->getElementType();
368 if (Value.getNode()->mergeTypeInfo(CurTy, Value.getOffset())) {
369 // If the node had to be folded... exit quickly
370 setDestTo(GEP, Value); // GEP result points to folded node
374 const TargetData &TD = Value.getNode()->getTargetData();
377 // Handle the pointer index specially...
378 if (GEP.getNumOperands() > 1 &&
379 (!isa<Constant>(GEP.getOperand(1)) ||
380 !cast<Constant>(GEP.getOperand(1))->isNullValue())) {
382 // If we already know this is an array being accessed, don't do anything...
383 if (!TopTypeRec.isArray) {
384 TopTypeRec.isArray = true;
386 // If we are treating some inner field pointer as an array, fold the node
387 // up because we cannot handle it right. This can come because of
388 // something like this: &((&Pt->X)[1]) == &Pt->Y
390 if (Value.getOffset()) {
391 // Value is now the pointer we want to GEP to be...
392 Value.getNode()->foldNodeCompletely();
393 setDestTo(GEP, Value); // GEP result points to folded node
396 // This is a pointer to the first byte of the node. Make sure that we
397 // are pointing to the outter most type in the node.
398 // FIXME: We need to check one more case here...
404 // All of these subscripts are indexing INTO the elements we have...
406 for (gep_type_iterator I = gep_type_begin(GEP), E = gep_type_end(GEP);
408 if (const StructType *STy = dyn_cast<StructType>(*I)) {
410 (unsigned)cast<ConstantUInt>(I.getOperand())->getValue();
411 Offset += (unsigned)TD.getStructLayout(STy)->MemberOffsets[FieldNo];
412 } else if (const PointerType *PTy = dyn_cast<PointerType>(*I)) {
413 if (!isa<Constant>(I.getOperand()) ||
414 !cast<Constant>(I.getOperand())->isNullValue())
415 Value.getNode()->setArrayMarker();
420 if (const SequentialType *STy = cast<SequentialType>(*I)) {
421 CurTy = STy->getElementType();
422 if (ConstantSInt *CS = dyn_cast<ConstantSInt>(GEP.getOperand(i))) {
423 Offset += CS->getValue()*TD.getTypeSize(CurTy);
425 // Variable index into a node. We must merge all of the elements of the
426 // sequential type here.
427 if (isa<PointerType>(STy))
428 std::cerr << "Pointer indexing not handled yet!\n";
430 const ArrayType *ATy = cast<ArrayType>(STy);
431 unsigned ElSize = TD.getTypeSize(CurTy);
432 DSNode *N = Value.getNode();
433 assert(N && "Value must have a node!");
434 unsigned RawOffset = Offset+Value.getOffset();
436 // Loop over all of the elements of the array, merging them into the
438 for (unsigned i = 1, e = ATy->getNumElements(); i != e; ++i)
439 // Merge all of the byte components of this array element
440 for (unsigned j = 0; j != ElSize; ++j)
441 N->mergeIndexes(RawOffset+j, RawOffset+i*ElSize+j);
447 // Add in the offset calculated...
448 Value.setOffset(Value.getOffset()+Offset);
451 DSNode *N = Value.getNode();
453 !N->isNodeCompletelyFolded() &&
454 (N->getSize() != 0 || Offset != 0) &&
455 !N->isForwarding()) {
456 if ((Offset >= N->getSize()) || int(Offset) < 0) {
457 // Accessing offsets out of node size range
458 // This is seen in the "magic" struct in named (from bind), where the
459 // fourth field is an array of length 0, presumably used to create struct
460 // instances of different sizes
462 // Collapse the node since its size is now variable
463 N->foldNodeCompletely();
467 // Value is now the pointer we want to GEP to be...
468 setDestTo(GEP, Value);
471 void GraphBuilder::visitLoadInst(LoadInst &LI) {
472 DSNodeHandle Ptr = getValueDest(*LI.getOperand(0));
476 // Make that the node is read from...
477 Ptr.getNode()->setReadMarker();
479 // Ensure a typerecord exists...
480 Ptr.getNode()->mergeTypeInfo(LI.getType(), Ptr.getOffset(), false);
482 if (isPointerType(LI.getType()))
483 setDestTo(LI, getLink(Ptr));
486 void GraphBuilder::visitStoreInst(StoreInst &SI) {
487 const Type *StoredTy = SI.getOperand(0)->getType();
488 DSNodeHandle Dest = getValueDest(*SI.getOperand(1));
489 if (Dest.isNull()) return;
491 // Mark that the node is written to...
492 Dest.getNode()->setModifiedMarker();
494 // Ensure a type-record exists...
495 Dest.getNode()->mergeTypeInfo(StoredTy, Dest.getOffset());
497 // Avoid adding edges from null, or processing non-"pointer" stores
498 if (isPointerType(StoredTy))
499 Dest.addEdgeTo(getValueDest(*SI.getOperand(0)));
502 void GraphBuilder::visitReturnInst(ReturnInst &RI) {
503 if (RI.getNumOperands() && isPointerType(RI.getOperand(0)->getType()))
504 RetNode->mergeWith(getValueDest(*RI.getOperand(0)));
507 void GraphBuilder::visitVAArgInst(VAArgInst &I) {
508 //FIXME: also updates the argument
509 DSNodeHandle Ptr = getValueDest(*I.getOperand(0));
510 if (Ptr.isNull()) return;
512 // Make that the node is read from.
513 Ptr.getNode()->setReadMarker();
515 // Ensure a type record exists.
516 DSNode *PtrN = Ptr.getNode();
517 PtrN->mergeTypeInfo(I.getType(), Ptr.getOffset(), false);
519 if (isPointerType(I.getType()))
520 setDestTo(I, getLink(Ptr));
524 void GraphBuilder::visitCallInst(CallInst &CI) {
528 void GraphBuilder::visitInvokeInst(InvokeInst &II) {
532 void GraphBuilder::visitCallSite(CallSite CS) {
533 Value *Callee = CS.getCalledValue();
535 // Special case handling of certain libc allocation functions here.
536 if (Function *F = dyn_cast<Function>(Callee))
538 switch (F->getIntrinsicID()) {
539 case Intrinsic::vastart:
540 getValueDest(*CS.getInstruction()).getNode()->setAllocaNodeMarker();
542 case Intrinsic::vacopy:
543 getValueDest(*CS.getInstruction()).
544 mergeWith(getValueDest(**(CS.arg_begin())));
546 case Intrinsic::vaend:
547 case Intrinsic::dbg_func_start:
548 case Intrinsic::dbg_region_end:
549 case Intrinsic::dbg_stoppoint:
551 case Intrinsic::memcpy_i32:
552 case Intrinsic::memcpy_i64:
553 case Intrinsic::memmove_i32:
554 case Intrinsic::memmove_i64: {
555 // Merge the first & second arguments, and mark the memory read and
557 DSNodeHandle RetNH = getValueDest(**CS.arg_begin());
558 RetNH.mergeWith(getValueDest(**(CS.arg_begin()+1)));
559 if (DSNode *N = RetNH.getNode())
560 N->setModifiedMarker()->setReadMarker();
563 case Intrinsic::memset_i32:
564 case Intrinsic::memset_i64:
565 // Mark the memory modified.
566 if (DSNode *N = getValueDest(**CS.arg_begin()).getNode())
567 N->setModifiedMarker();
570 // Determine if the called function is one of the specified heap
571 // allocation functions
572 for (cl::list<std::string>::iterator AllocFunc = AllocList.begin(),
573 LastAllocFunc = AllocList.end();
574 AllocFunc != LastAllocFunc;
576 if (F->getName() == *(AllocFunc)) {
577 setDestTo(*CS.getInstruction(),
578 createNode()->setHeapNodeMarker()->setModifiedMarker());
583 // Determine if the called function is one of the specified heap
585 for (cl::list<std::string>::iterator FreeFunc = FreeList.begin(),
586 LastFreeFunc = FreeList.end();
587 FreeFunc != LastFreeFunc;
589 if (F->getName() == *(FreeFunc)) {
590 // Mark that the node is written to...
591 if (DSNode *N = getValueDest(*(CS.getArgument(0))).getNode())
592 N->setModifiedMarker()->setHeapNodeMarker();
597 //gets select localtime ioctl
599 if ((F->isExternal() && F->getName() == "calloc")
600 || F->getName() == "posix_memalign"
601 || F->getName() == "memalign" || F->getName() == "valloc") {
602 setDestTo(*CS.getInstruction(),
603 createNode()->setHeapNodeMarker()->setModifiedMarker());
605 } else if (F->getName() == "realloc") {
606 DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
607 if (CS.arg_begin() != CS.arg_end())
608 RetNH.mergeWith(getValueDest(**CS.arg_begin()));
609 if (DSNode *N = RetNH.getNode())
610 N->setHeapNodeMarker()->setModifiedMarker()->setReadMarker();
612 } else if (F->getName() == "memmove") {
613 // Merge the first & second arguments, and mark the memory read and
615 DSNodeHandle RetNH = getValueDest(**CS.arg_begin());
616 RetNH.mergeWith(getValueDest(**(CS.arg_begin()+1)));
617 if (DSNode *N = RetNH.getNode())
618 N->setModifiedMarker()->setReadMarker();
620 } else if (F->getName() == "free") {
621 // Mark that the node is written to...
622 if (DSNode *N = getValueDest(**CS.arg_begin()).getNode())
623 N->setModifiedMarker()->setHeapNodeMarker();
624 } else if (F->getName() == "atoi" || F->getName() == "atof" ||
625 F->getName() == "atol" || F->getName() == "atoll" ||
626 F->getName() == "remove" || F->getName() == "unlink" ||
627 F->getName() == "rename" || F->getName() == "memcmp" ||
628 F->getName() == "strcmp" || F->getName() == "strncmp" ||
629 F->getName() == "execl" || F->getName() == "execlp" ||
630 F->getName() == "execle" || F->getName() == "execv" ||
631 F->getName() == "execvp" || F->getName() == "chmod" ||
632 F->getName() == "puts" || F->getName() == "write" ||
633 F->getName() == "open" || F->getName() == "create" ||
634 F->getName() == "truncate" || F->getName() == "chdir" ||
635 F->getName() == "mkdir" || F->getName() == "rmdir" ||
636 F->getName() == "strlen") {
637 // These functions read all of their pointer operands.
638 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
640 if (isPointerType((*AI)->getType()))
641 if (DSNode *N = getValueDest(**AI).getNode())
645 } else if (F->getName() == "memchr") {
646 DSNodeHandle RetNH = getValueDest(**CS.arg_begin());
647 DSNodeHandle Result = getValueDest(*CS.getInstruction());
648 RetNH.mergeWith(Result);
649 if (DSNode *N = RetNH.getNode())
652 } else if (F->getName() == "read" || F->getName() == "pipe" ||
653 F->getName() == "wait" || F->getName() == "time" ||
654 F->getName() == "getrusage") {
655 // These functions write all of their pointer operands.
656 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
658 if (isPointerType((*AI)->getType()))
659 if (DSNode *N = getValueDest(**AI).getNode())
660 N->setModifiedMarker();
663 } else if (F->getName() == "stat" || F->getName() == "fstat" ||
664 F->getName() == "lstat") {
665 // These functions read their first operand if its a pointer.
666 CallSite::arg_iterator AI = CS.arg_begin();
667 if (isPointerType((*AI)->getType())) {
668 DSNodeHandle Path = getValueDest(**AI);
669 if (DSNode *N = Path.getNode()) N->setReadMarker();
672 // Then they write into the stat buffer.
673 DSNodeHandle StatBuf = getValueDest(**++AI);
674 if (DSNode *N = StatBuf.getNode()) {
675 N->setModifiedMarker();
676 const Type *StatTy = F->getFunctionType()->getParamType(1);
677 if (const PointerType *PTy = dyn_cast<PointerType>(StatTy))
678 N->mergeTypeInfo(PTy->getElementType(), StatBuf.getOffset());
681 } else if (F->getName() == "strtod" || F->getName() == "strtof" ||
682 F->getName() == "strtold") {
683 // These functions read the first pointer
684 if (DSNode *Str = getValueDest(**CS.arg_begin()).getNode()) {
685 Str->setReadMarker();
686 // If the second parameter is passed, it will point to the first
688 const DSNodeHandle &EndPtrNH = getValueDest(**(CS.arg_begin()+1));
689 if (DSNode *End = EndPtrNH.getNode()) {
690 End->mergeTypeInfo(PointerType::get(Type::SByteTy),
691 EndPtrNH.getOffset(), false);
692 End->setModifiedMarker();
693 DSNodeHandle &Link = getLink(EndPtrNH);
694 Link.mergeWith(getValueDest(**CS.arg_begin()));
698 } else if (F->getName() == "fopen" || F->getName() == "fdopen" ||
699 F->getName() == "freopen") {
700 // These functions read all of their pointer operands.
701 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
703 if (isPointerType((*AI)->getType()))
704 if (DSNode *N = getValueDest(**AI).getNode())
707 // fopen allocates in an unknown way and writes to the file
708 // descriptor. Also, merge the allocated type into the node.
709 DSNodeHandle Result = getValueDest(*CS.getInstruction());
710 if (DSNode *N = Result.getNode()) {
711 N->setModifiedMarker()->setUnknownNodeMarker();
712 const Type *RetTy = F->getFunctionType()->getReturnType();
713 if (const PointerType *PTy = dyn_cast<PointerType>(RetTy))
714 N->mergeTypeInfo(PTy->getElementType(), Result.getOffset());
717 // If this is freopen, merge the file descriptor passed in with the
719 if (F->getName() == "freopen") {
720 // ICC doesn't handle getting the iterator, decrementing and
721 // dereferencing it in one operation without error. Do it in 2 steps
722 CallSite::arg_iterator compit = CS.arg_end();
723 Result.mergeWith(getValueDest(**--compit));
726 } else if (F->getName() == "fclose" && CS.arg_end()-CS.arg_begin() ==1){
727 // fclose reads and deallocates the memory in an unknown way for the
728 // file descriptor. It merges the FILE type into the descriptor.
729 DSNodeHandle H = getValueDest(**CS.arg_begin());
730 if (DSNode *N = H.getNode()) {
731 N->setReadMarker()->setUnknownNodeMarker();
732 const Type *ArgTy = F->getFunctionType()->getParamType(0);
733 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
734 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
737 } else if (CS.arg_end()-CS.arg_begin() == 1 &&
738 (F->getName() == "fflush" || F->getName() == "feof" ||
739 F->getName() == "fileno" || F->getName() == "clearerr" ||
740 F->getName() == "rewind" || F->getName() == "ftell" ||
741 F->getName() == "ferror" || F->getName() == "fgetc" ||
742 F->getName() == "fgetc" || F->getName() == "_IO_getc")) {
743 // fflush reads and writes the memory for the file descriptor. It
744 // merges the FILE type into the descriptor.
745 DSNodeHandle H = getValueDest(**CS.arg_begin());
746 if (DSNode *N = H.getNode()) {
747 N->setReadMarker()->setModifiedMarker();
749 const Type *ArgTy = F->getFunctionType()->getParamType(0);
750 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
751 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
754 } else if (CS.arg_end()-CS.arg_begin() == 4 &&
755 (F->getName() == "fwrite" || F->getName() == "fread")) {
756 // fread writes the first operand, fwrite reads it. They both
757 // read/write the FILE descriptor, and merges the FILE type.
758 CallSite::arg_iterator compit = CS.arg_end();
759 DSNodeHandle H = getValueDest(**--compit);
760 if (DSNode *N = H.getNode()) {
761 N->setReadMarker()->setModifiedMarker();
762 const Type *ArgTy = F->getFunctionType()->getParamType(3);
763 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
764 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
767 H = getValueDest(**CS.arg_begin());
768 if (DSNode *N = H.getNode())
769 if (F->getName() == "fwrite")
772 N->setModifiedMarker();
774 } else if (F->getName() == "fgets" && CS.arg_end()-CS.arg_begin() == 3){
775 // fgets reads and writes the memory for the file descriptor. It
776 // merges the FILE type into the descriptor, and writes to the
777 // argument. It returns the argument as well.
778 CallSite::arg_iterator AI = CS.arg_begin();
779 DSNodeHandle H = getValueDest(**AI);
780 if (DSNode *N = H.getNode())
781 N->setModifiedMarker(); // Writes buffer
782 H.mergeWith(getValueDest(*CS.getInstruction())); // Returns buffer
785 // Reads and writes file descriptor, merge in FILE type.
786 H = getValueDest(**AI);
787 if (DSNode *N = H.getNode()) {
788 N->setReadMarker()->setModifiedMarker();
789 const Type *ArgTy = F->getFunctionType()->getParamType(2);
790 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
791 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
794 } else if (F->getName() == "ungetc" || F->getName() == "fputc" ||
795 F->getName() == "fputs" || F->getName() == "putc" ||
796 F->getName() == "ftell" || F->getName() == "rewind" ||
797 F->getName() == "_IO_putc") {
798 // These functions read and write the memory for the file descriptor,
799 // which is passes as the last argument.
800 CallSite::arg_iterator compit = CS.arg_end();
801 DSNodeHandle H = getValueDest(**--compit);
802 if (DSNode *N = H.getNode()) {
803 N->setReadMarker()->setModifiedMarker();
804 FunctionType::param_iterator compit2 = F->getFunctionType()->param_end();
805 const Type *ArgTy = *--compit2;
806 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
807 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
810 // Any pointer arguments are read.
811 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
813 if (isPointerType((*AI)->getType()))
814 if (DSNode *N = getValueDest(**AI).getNode())
817 } else if (F->getName() == "fseek" || F->getName() == "fgetpos" ||
818 F->getName() == "fsetpos") {
819 // These functions read and write the memory for the file descriptor,
820 // and read/write all other arguments.
821 DSNodeHandle H = getValueDest(**CS.arg_begin());
822 if (DSNode *N = H.getNode()) {
823 FunctionType::param_iterator compit2 = F->getFunctionType()->param_end();
824 const Type *ArgTy = *--compit2;
825 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
826 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
829 // Any pointer arguments are read.
830 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
832 if (isPointerType((*AI)->getType()))
833 if (DSNode *N = getValueDest(**AI).getNode())
834 N->setReadMarker()->setModifiedMarker();
836 } else if (F->getName() == "printf" || F->getName() == "fprintf" ||
837 F->getName() == "sprintf") {
838 CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
840 if (F->getName() == "fprintf") {
841 // fprintf reads and writes the FILE argument, and applies the type
843 DSNodeHandle H = getValueDest(**AI);
844 if (DSNode *N = H.getNode()) {
845 N->setModifiedMarker();
846 const Type *ArgTy = (*AI)->getType();
847 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
848 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
850 } else if (F->getName() == "sprintf") {
851 // sprintf writes the first string argument.
852 DSNodeHandle H = getValueDest(**AI++);
853 if (DSNode *N = H.getNode()) {
854 N->setModifiedMarker();
855 const Type *ArgTy = (*AI)->getType();
856 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
857 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
861 for (; AI != E; ++AI) {
862 // printf reads all pointer arguments.
863 if (isPointerType((*AI)->getType()))
864 if (DSNode *N = getValueDest(**AI).getNode())
868 } else if (F->getName() == "vprintf" || F->getName() == "vfprintf" ||
869 F->getName() == "vsprintf") {
870 CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
872 if (F->getName() == "vfprintf") {
873 // ffprintf reads and writes the FILE argument, and applies the type
875 DSNodeHandle H = getValueDest(**AI);
876 if (DSNode *N = H.getNode()) {
877 N->setModifiedMarker()->setReadMarker();
878 const Type *ArgTy = (*AI)->getType();
879 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
880 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
883 } else if (F->getName() == "vsprintf") {
884 // vsprintf writes the first string argument.
885 DSNodeHandle H = getValueDest(**AI++);
886 if (DSNode *N = H.getNode()) {
887 N->setModifiedMarker();
888 const Type *ArgTy = (*AI)->getType();
889 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
890 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
896 if (isPointerType((*AI)->getType()))
897 if (DSNode *N = getValueDest(**AI).getNode())
902 // Read the valist, and the pointed-to objects.
903 if (AI != E && isPointerType((*AI)->getType())) {
904 const DSNodeHandle &VAList = getValueDest(**AI);
905 if (DSNode *N = VAList.getNode()) {
907 N->mergeTypeInfo(PointerType::get(Type::SByteTy),
908 VAList.getOffset(), false);
910 DSNodeHandle &VAListObjs = getLink(VAList);
911 VAListObjs.getNode()->setReadMarker();
916 } else if (F->getName() == "scanf" || F->getName() == "fscanf" ||
917 F->getName() == "sscanf") {
918 CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
920 if (F->getName() == "fscanf") {
921 // fscanf reads and writes the FILE argument, and applies the type
923 DSNodeHandle H = getValueDest(**AI);
924 if (DSNode *N = H.getNode()) {
926 const Type *ArgTy = (*AI)->getType();
927 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
928 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
930 } else if (F->getName() == "sscanf") {
931 // sscanf reads the first string argument.
932 DSNodeHandle H = getValueDest(**AI++);
933 if (DSNode *N = H.getNode()) {
935 const Type *ArgTy = (*AI)->getType();
936 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
937 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
941 for (; AI != E; ++AI) {
942 // scanf writes all pointer arguments.
943 if (isPointerType((*AI)->getType()))
944 if (DSNode *N = getValueDest(**AI).getNode())
945 N->setModifiedMarker();
948 } else if (F->getName() == "strtok") {
949 // strtok reads and writes the first argument, returning it. It reads
950 // its second arg. FIXME: strtok also modifies some hidden static
951 // data. Someday this might matter.
952 CallSite::arg_iterator AI = CS.arg_begin();
953 DSNodeHandle H = getValueDest(**AI++);
954 if (DSNode *N = H.getNode()) {
955 N->setReadMarker()->setModifiedMarker(); // Reads/Writes buffer
956 const Type *ArgTy = F->getFunctionType()->getParamType(0);
957 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
958 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
960 H.mergeWith(getValueDest(*CS.getInstruction())); // Returns buffer
962 H = getValueDest(**AI); // Reads delimiter
963 if (DSNode *N = H.getNode()) {
965 const Type *ArgTy = F->getFunctionType()->getParamType(1);
966 if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
967 N->mergeTypeInfo(PTy->getElementType(), H.getOffset());
970 } else if (F->getName() == "strchr" || F->getName() == "strrchr" ||
971 F->getName() == "strstr") {
972 // These read their arguments, and return the first one
973 DSNodeHandle H = getValueDest(**CS.arg_begin());
974 H.mergeWith(getValueDest(*CS.getInstruction())); // Returns buffer
976 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
978 if (isPointerType((*AI)->getType()))
979 if (DSNode *N = getValueDest(**AI).getNode())
982 if (DSNode *N = H.getNode())
985 } else if (F->getName() == "__assert_fail") {
986 for (CallSite::arg_iterator AI = CS.arg_begin(), E = CS.arg_end();
988 if (isPointerType((*AI)->getType()))
989 if (DSNode *N = getValueDest(**AI).getNode())
992 } else if (F->getName() == "modf" && CS.arg_end()-CS.arg_begin() == 2) {
993 // This writes its second argument, and forces it to double.
994 CallSite::arg_iterator compit = CS.arg_end();
995 DSNodeHandle H = getValueDest(**--compit);
996 if (DSNode *N = H.getNode()) {
997 N->setModifiedMarker();
998 N->mergeTypeInfo(Type::DoubleTy, H.getOffset());
1001 } else if (F->getName() == "strcat" || F->getName() == "strncat") {
1002 //This might be making unsafe assumptions about usage
1003 //Merge return and first arg
1004 DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
1005 RetNH.mergeWith(getValueDest(**CS.arg_begin()));
1006 if (DSNode *N = RetNH.getNode())
1007 N->setHeapNodeMarker()->setModifiedMarker()->setReadMarker();
1008 //and read second pointer
1009 if (DSNode *N = getValueDest(**(CS.arg_begin() + 1)).getNode())
1012 } else if (F->getName() == "strcpy" || F->getName() == "strncpy") {
1013 //This might be making unsafe assumptions about usage
1014 //Merge return and first arg
1015 DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
1016 RetNH.mergeWith(getValueDest(**CS.arg_begin()));
1017 if (DSNode *N = RetNH.getNode())
1018 N->setHeapNodeMarker()->setModifiedMarker();
1019 //and read second pointer
1020 if (DSNode *N = getValueDest(**(CS.arg_begin() + 1)).getNode())
1024 // Unknown function, warn if it returns a pointer type or takes a
1025 // pointer argument.
1026 bool Warn = isPointerType(CS.getInstruction()->getType());
1028 for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
1030 if (isPointerType((*I)->getType())) {
1035 DEBUG(std::cerr << "WARNING: Call to unknown external function '"
1036 << F->getName() << "' will cause pessimistic results!\n");
1042 // Set up the return value...
1043 DSNodeHandle RetVal;
1044 Instruction *I = CS.getInstruction();
1045 if (isPointerType(I->getType()))
1046 RetVal = getValueDest(*I);
1048 DSNode *CalleeNode = 0;
1049 if (DisableDirectCallOpt || !isa<Function>(Callee)) {
1050 CalleeNode = getValueDest(*Callee).getNode();
1051 if (CalleeNode == 0) {
1052 std::cerr << "WARNING: Program is calling through a null pointer?\n"<< *I;
1053 return; // Calling a null pointer?
1057 std::vector<DSNodeHandle> Args;
1058 Args.reserve(CS.arg_end()-CS.arg_begin());
1060 // Calculate the arguments vector...
1061 for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
1062 if (isPointerType((*I)->getType()))
1063 Args.push_back(getValueDest(**I));
1065 // Add a new function call entry...
1067 FunctionCalls->push_back(DSCallSite(CS, RetVal, CalleeNode, Args));
1069 FunctionCalls->push_back(DSCallSite(CS, RetVal, cast<Function>(Callee),
1073 void GraphBuilder::visitFreeInst(FreeInst &FI) {
1074 // Mark that the node is written to...
1075 if (DSNode *N = getValueDest(*FI.getOperand(0)).getNode())
1076 N->setModifiedMarker()->setHeapNodeMarker();
1080 void GraphBuilder::visitCastInst(CastInst &CI) {
1081 if (isPointerType(CI.getType()))
1082 if (isPointerType(CI.getOperand(0)->getType())) {
1083 DSNodeHandle Ptr = getValueDest(*CI.getOperand(0));
1084 if (Ptr.getNode() == 0) return;
1086 // Cast one pointer to the other, just act like a copy instruction
1089 // Cast something (floating point, small integer) to a pointer. We need
1090 // to track the fact that the node points to SOMETHING, just something we
1091 // don't know about. Make an "Unknown" node.
1093 setDestTo(CI, createNode()->setUnknownNodeMarker());
1098 // visitInstruction - For all other instruction types, if we have any arguments
1099 // that are of pointer type, make them have unknown composition bits, and merge
1100 // the nodes together.
1101 void GraphBuilder::visitInstruction(Instruction &Inst) {
1102 DSNodeHandle CurNode;
1103 if (isPointerType(Inst.getType()))
1104 CurNode = getValueDest(Inst);
1105 for (User::op_iterator I = Inst.op_begin(), E = Inst.op_end(); I != E; ++I)
1106 if (isPointerType((*I)->getType()))
1107 CurNode.mergeWith(getValueDest(**I));
1109 if (DSNode *N = CurNode.getNode())
1110 N->setUnknownNodeMarker();
1115 //===----------------------------------------------------------------------===//
1116 // LocalDataStructures Implementation
1117 //===----------------------------------------------------------------------===//
1119 // MergeConstantInitIntoNode - Merge the specified constant into the node
1120 // pointed to by NH.
1121 void GraphBuilder::MergeConstantInitIntoNode(DSNodeHandle &NH, Constant *C) {
1122 // Ensure a type-record exists...
1123 DSNode *NHN = NH.getNode();
1124 NHN->mergeTypeInfo(C->getType(), NH.getOffset());
1126 if (C->getType()->isFirstClassType()) {
1127 if (isPointerType(C->getType()))
1128 // Avoid adding edges from null, or processing non-"pointer" stores
1129 NH.addEdgeTo(getValueDest(*C));
1133 const TargetData &TD = NH.getNode()->getTargetData();
1135 if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
1136 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1137 // We don't currently do any indexing for arrays...
1138 MergeConstantInitIntoNode(NH, cast<Constant>(CA->getOperand(i)));
1139 } else if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
1140 const StructLayout *SL = TD.getStructLayout(CS->getType());
1141 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1142 DSNode *NHN = NH.getNode();
1143 //Some programmers think ending a structure with a [0 x sbyte] is cute
1144 if (SL->MemberOffsets[i] < SL->StructSize) {
1145 DSNodeHandle NewNH(NHN, NH.getOffset()+(unsigned)SL->MemberOffsets[i]);
1146 MergeConstantInitIntoNode(NewNH, cast<Constant>(CS->getOperand(i)));
1147 } else if (SL->MemberOffsets[i] == SL->StructSize) {
1148 DEBUG(std::cerr << "Zero size element at end of struct\n");
1149 NHN->foldNodeCompletely();
1151 assert(0 && "type was smaller than offsets of of struct layout indicate");
1154 } else if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) {
1157 assert(0 && "Unknown constant type!");
1161 void GraphBuilder::mergeInGlobalInitializer(GlobalVariable *GV) {
1162 assert(!GV->isExternal() && "Cannot merge in external global!");
1163 // Get a node handle to the global node and merge the initializer into it.
1164 DSNodeHandle NH = getValueDest(*GV);
1165 MergeConstantInitIntoNode(NH, GV->getInitializer());
1169 /// BuildGlobalECs - Look at all of the nodes in the globals graph. If any node
1170 /// contains multiple globals, DSA will never, ever, be able to tell the globals
1171 /// apart. Instead of maintaining this information in all of the graphs
1172 /// throughout the entire program, store only a single global (the "leader") in
1173 /// the graphs, and build equivalence classes for the rest of the globals.
1174 static void BuildGlobalECs(DSGraph &GG, std::set<GlobalValue*> &ECGlobals) {
1175 DSScalarMap &SM = GG.getScalarMap();
1176 EquivalenceClasses<GlobalValue*> &GlobalECs = SM.getGlobalECs();
1177 for (DSGraph::node_iterator I = GG.node_begin(), E = GG.node_end();
1179 if (I->getGlobalsList().size() <= 1) continue;
1181 // First, build up the equivalence set for this block of globals.
1182 const std::vector<GlobalValue*> &GVs = I->getGlobalsList();
1183 GlobalValue *First = GVs[0];
1184 for (unsigned i = 1, e = GVs.size(); i != e; ++i)
1185 GlobalECs.unionSets(First, GVs[i]);
1187 // Next, get the leader element.
1188 assert(First == GlobalECs.getLeaderValue(First) &&
1189 "First did not end up being the leader?");
1191 // Next, remove all globals from the scalar map that are not the leader.
1192 assert(GVs[0] == First && "First had to be at the front!");
1193 for (unsigned i = 1, e = GVs.size(); i != e; ++i) {
1194 ECGlobals.insert(GVs[i]);
1195 SM.erase(SM.find(GVs[i]));
1198 // Finally, change the global node to only contain the leader.
1200 I->addGlobal(First);
1203 DEBUG(GG.AssertGraphOK());
1206 /// EliminateUsesOfECGlobals - Once we have determined that some globals are in
1207 /// really just equivalent to some other globals, remove the globals from the
1208 /// specified DSGraph (if present), and merge any nodes with their leader nodes.
1209 static void EliminateUsesOfECGlobals(DSGraph &G,
1210 const std::set<GlobalValue*> &ECGlobals) {
1211 DSScalarMap &SM = G.getScalarMap();
1212 EquivalenceClasses<GlobalValue*> &GlobalECs = SM.getGlobalECs();
1214 bool MadeChange = false;
1215 for (DSScalarMap::global_iterator GI = SM.global_begin(), E = SM.global_end();
1217 GlobalValue *GV = *GI++;
1218 if (!ECGlobals.count(GV)) continue;
1220 const DSNodeHandle &GVNH = SM[GV];
1221 assert(!GVNH.isNull() && "Global has null NH!?");
1223 // Okay, this global is in some equivalence class. Start by finding the
1224 // leader of the class.
1225 GlobalValue *Leader = GlobalECs.getLeaderValue(GV);
1227 // If the leader isn't already in the graph, insert it into the node
1228 // corresponding to GV.
1229 if (!SM.global_count(Leader)) {
1230 GVNH.getNode()->addGlobal(Leader);
1233 // Otherwise, the leader is in the graph, make sure the nodes are the
1234 // merged in the specified graph.
1235 const DSNodeHandle &LNH = SM[Leader];
1236 if (LNH.getNode() != GVNH.getNode())
1237 LNH.mergeWith(GVNH);
1240 // Next step, remove the global from the DSNode.
1241 GVNH.getNode()->removeGlobal(GV);
1243 // Finally, remove the global from the ScalarMap.
1248 DEBUG(if(MadeChange) G.AssertGraphOK());
1251 bool LocalDataStructures::runOnModule(Module &M) {
1252 const TargetData &TD = getAnalysis<TargetData>();
1254 // First step, build the globals graph.
1255 GlobalsGraph = new DSGraph(GlobalECs, TD);
1257 GraphBuilder GGB(*GlobalsGraph);
1259 // Add initializers for all of the globals to the globals graph.
1260 for (Module::global_iterator I = M.global_begin(), E = M.global_end();
1262 if (!I->isExternal())
1263 GGB.mergeInGlobalInitializer(I);
1266 // Next step, iterate through the nodes in the globals graph, unioning
1267 // together the globals into equivalence classes.
1268 std::set<GlobalValue*> ECGlobals;
1269 BuildGlobalECs(*GlobalsGraph, ECGlobals);
1270 DEBUG(std::cerr << "Eliminating " << ECGlobals.size() << " EC Globals!\n");
1273 // Calculate all of the graphs...
1274 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
1275 if (!I->isExternal())
1276 DSInfo.insert(std::make_pair(I, new DSGraph(GlobalECs, TD, *I,
1279 GlobalsGraph->removeTriviallyDeadNodes();
1280 GlobalsGraph->markIncompleteNodes(DSGraph::MarkFormalArgs);
1282 // Now that we've computed all of the graphs, and merged all of the info into
1283 // the globals graph, see if we have further constrained the globals in the
1284 // program if so, update GlobalECs and remove the extraneous globals from the
1286 BuildGlobalECs(*GlobalsGraph, ECGlobals);
1287 if (!ECGlobals.empty()) {
1288 DEBUG(std::cerr << "Eliminating " << ECGlobals.size() << " EC Globals!\n");
1289 for (hash_map<Function*, DSGraph*>::iterator I = DSInfo.begin(),
1290 E = DSInfo.end(); I != E; ++I)
1291 EliminateUsesOfECGlobals(*I->second, ECGlobals);
1297 // releaseMemory - If the pass pipeline is done with this pass, we can release
1298 // our memory... here...
1300 void LocalDataStructures::releaseMemory() {
1301 for (hash_map<Function*, DSGraph*>::iterator I = DSInfo.begin(),
1302 E = DSInfo.end(); I != E; ++I) {
1303 I->second->getReturnNodes().erase(I->first);
1304 if (I->second->getReturnNodes().empty())
1308 // Empty map so next time memory is released, data structures are not
1311 delete GlobalsGraph;