1 //===- LevelRaise.cpp - Code to change LLVM to higher level -----------------=//
3 // This file implements the 'raising' part of the LevelChange API. This is
4 // useful because, in general, it makes the LLVM code terser and easier to
5 // analyze. Note that it is good to run DCE after doing this transformation.
7 // Eliminate silly things in the source that do not effect the level, but do
10 // - getelementptr/load & getelementptr/store are folded into a direct
12 // - Convert this code (for both alloca and malloc):
13 // %reg110 = shl uint %n, ubyte 2 ;;<uint>
14 // %reg108 = alloca ubyte, uint %reg110 ;;<ubyte*>
15 // %cast76 = cast ubyte* %reg108 to uint* ;;<uint*>
16 // To: %cast76 = alloca uint, uint %n
17 // Convert explicit addressing to use getelementptr instruction where possible
20 // Convert explicit addressing on pointers to use getelementptr instruction.
21 // - If a pointer is used by arithmetic operation, insert an array casted
22 // version into the source program, only for the following pointer types:
23 // * Method argument pointers
24 // - Pointers returned by alloca or malloc
25 // - Pointers returned by function calls
26 // - If a pointer is indexed with a value scaled by a constant size equal
27 // to the element size of the array, the expression is replaced with a
28 // getelementptr instruction.
30 //===----------------------------------------------------------------------===//
32 #include "llvm/Transforms/LevelChange.h"
33 #include "llvm/Method.h"
34 #include "llvm/Support/STLExtras.h"
35 #include "llvm/iOther.h"
36 #include "llvm/iMemory.h"
37 #include "llvm/ConstPoolVals.h"
38 #include "llvm/Target/TargetData.h"
39 #include "llvm/Optimizations/ConstantHandling.h"
43 #include "llvm/Assembly/Writer.h"
45 //#define DEBUG_PEEPHOLE_INSTS 1
47 #ifdef DEBUG_PEEPHOLE_INSTS
48 #define PRINT_PEEPHOLE(ID, NUM, I) \
49 cerr << "Inst P/H " << ID << "[" << NUM << "] " << I;
51 #define PRINT_PEEPHOLE(ID, NUM, I)
54 #define PRINT_PEEPHOLE1(ID, I1) do { PRINT_PEEPHOLE(ID, 0, I1); } while (0)
55 #define PRINT_PEEPHOLE2(ID, I1, I2) \
56 do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); } while (0)
57 #define PRINT_PEEPHOLE3(ID, I1, I2, I3) \
58 do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); \
59 PRINT_PEEPHOLE(ID, 2, I3); } while (0)
62 // TargetData Hack: Eventually we will have annotations given to us by the
63 // backend so that we know stuff about type size and alignments. For now
64 // though, just use this, because it happens to match the model that GCC uses.
66 const TargetData TD("LevelRaise: Should be GCC though!");
69 // losslessCastableTypes - Return true if the types are bitwise equivalent.
70 // This predicate returns true if it is possible to cast from one type to
71 // another without gaining or losing precision, or altering the bits in any way.
73 static bool losslessCastableTypes(const Type *T1, const Type *T2) {
74 if (!T1->isPrimitiveType() && !isa<PointerType>(T1)) return false;
75 if (!T2->isPrimitiveType() && !isa<PointerType>(T2)) return false;
77 if (T1->getPrimitiveID() == T2->getPrimitiveID())
78 return true; // Handles identity cast, and cast of differing pointer types
80 // Now we know that they are two differing primitive or pointer types
81 switch (T1->getPrimitiveID()) {
82 case Type::UByteTyID: return T2 == Type::SByteTy;
83 case Type::SByteTyID: return T2 == Type::UByteTy;
84 case Type::UShortTyID: return T2 == Type::ShortTy;
85 case Type::ShortTyID: return T2 == Type::UShortTy;
86 case Type::UIntTyID: return T2 == Type::IntTy;
87 case Type::IntTyID: return T2 == Type::UIntTy;
90 case Type::PointerTyID:
91 return T2 == Type::ULongTy || T2 == Type::LongTy ||
92 T2->getPrimitiveID() == Type::PointerTyID;
94 return false; // Other types have no identity values
99 // isReinterpretingCast - Return true if the cast instruction specified will
100 // cause the operand to be "reinterpreted". A value is reinterpreted if the
101 // cast instruction would cause the underlying bits to change.
103 static inline bool isReinterpretingCast(const CastInst *CI) {
104 return !losslessCastableTypes(CI->getOperand(0)->getType(), CI->getType());
108 // getPointedToStruct - If the argument is a pointer type, and the pointed to
109 // value is a struct type, return the struct type, else return null.
111 static const StructType *getPointedToStruct(const Type *Ty) {
112 const PointerType *PT = dyn_cast<PointerType>(Ty);
113 return PT ? dyn_cast<StructType>(PT->getValueType()) : 0;
117 // getStructOffsetType - Return a vector of offsets that are to be used to index
118 // into the specified struct type to get as close as possible to index as we
119 // can. Note that it is possible that we cannot get exactly to Offset, in which
120 // case we update offset to be the offset we actually obtained. The resultant
121 // leaf type is returned.
123 static const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
124 vector<ConstPoolVal*> &Offsets) {
125 if (!isa<StructType>(Ty)) {
126 Offset = 0; // Return the offset that we were able to acheive
127 return Ty; // Return the leaf type
130 assert(Offset < TD.getTypeSize(Ty) && "Offset not in struct!");
131 const StructType *STy = cast<StructType>(Ty);
132 const StructLayout *SL = TD.getStructLayout(STy);
134 // This loop terminates always on a 0 <= i < MemberOffsets.size()
136 for (i = 0; i < SL->MemberOffsets.size()-1; ++i)
137 if (Offset >= SL->MemberOffsets[i] && Offset < SL->MemberOffsets[i+1])
140 assert(Offset >= SL->MemberOffsets[i] && Offset < SL->MemberOffsets[i+1]);
142 // Make sure to save the current index...
143 Offsets.push_back(ConstPoolUInt::get(Type::UByteTy, i));
145 unsigned SubOffs = Offset - SL->MemberOffsets[i];
146 const Type *LeafTy = getStructOffsetType(STy->getElementTypes()[i], SubOffs,
148 Offset = SL->MemberOffsets[i] + SubOffs;
154 // ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
155 // with a value, then remove and delete the original instruction.
157 static void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
158 BasicBlock::iterator &BI, Value *V) {
159 Instruction *I = *BI;
160 // Replaces all of the uses of the instruction with uses of the value
161 I->replaceAllUsesWith(V);
163 // Remove the unneccesary instruction now...
166 // Make sure to propogate a name if there is one already...
167 if (I->hasName() && !V->hasName())
168 V->setName(I->getName(), BIL.getParent()->getSymbolTable());
170 // Remove the dead instruction now...
175 // ReplaceInstWithInst - Replace the instruction specified by BI with the
176 // instruction specified by I. The original instruction is deleted and BI is
177 // updated to point to the new instruction.
179 static void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
180 BasicBlock::iterator &BI, Instruction *I) {
181 assert(I->getParent() == 0 &&
182 "ReplaceInstWithInst: Instruction already inserted into basic block!");
184 // Insert the new instruction into the basic block...
185 BI = BIL.insert(BI, I)+1;
187 // Replace all uses of the old instruction, and delete it.
188 ReplaceInstWithValue(BIL, BI, I);
190 // Reexamine the instruction just inserted next time around the cleanup pass
196 // ExpressionConvertableToType - Return true if it is possible
197 static bool ExpressionConvertableToType(Value *V, const Type *Ty) {
198 Instruction *I = dyn_cast<Instruction>(V);
200 // It's not an instruction, check to see if it's a constant... all constants
201 // can be converted to an equivalent value (except pointers, they can't be
202 // const prop'd in general).
204 if (isa<ConstPoolVal>(V) &&
205 !isa<PointerType>(V->getType()) && !isa<PointerType>(Ty)) return true;
207 return false; // Otherwise, we can't convert!
209 if (I->getType() == Ty) return false; // Expression already correct type!
211 switch (I->getOpcode()) {
212 case Instruction::Cast:
213 // We can convert the expr if the cast destination type is losslessly
214 // convertable to the requested type.
215 return losslessCastableTypes(Ty, I->getType());
217 case Instruction::Add:
218 case Instruction::Sub:
219 return ExpressionConvertableToType(I->getOperand(0), Ty) &&
220 ExpressionConvertableToType(I->getOperand(1), Ty);
221 case Instruction::Shl:
222 case Instruction::Shr:
223 return ExpressionConvertableToType(I->getOperand(0), Ty);
229 static Value *ConvertExpressionToType(Value *V, const Type *Ty) {
230 assert(ExpressionConvertableToType(V, Ty) && "Value is not convertable!");
231 Instruction *I = dyn_cast<Instruction>(V);
233 if (ConstPoolVal *CPV = cast<ConstPoolVal>(V)) {
234 // Constants are converted by constant folding the cast that is required.
235 // We assume here that all casts are implemented for constant prop.
236 Value *Result = opt::ConstantFoldCastInstruction(CPV, Ty);
237 if (!Result) cerr << "Couldn't fold " << CPV << " to " << Ty << endl;
238 assert(Result && "ConstantFoldCastInstruction Failed!!!");
243 BasicBlock *BB = I->getParent();
244 BasicBlock::InstListType &BIL = BB->getInstList();
245 string Name = I->getName(); if (!Name.empty()) I->setName("");
246 Instruction *Res; // Result of conversion
248 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
250 switch (I->getOpcode()) {
251 case Instruction::Cast:
252 Res = new CastInst(I->getOperand(0), Ty, Name);
255 case Instruction::Add:
256 case Instruction::Sub:
257 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
258 ConvertExpressionToType(I->getOperand(0), Ty),
259 ConvertExpressionToType(I->getOperand(1), Ty),
263 case Instruction::Shl:
264 case Instruction::Shr:
265 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(),
266 ConvertExpressionToType(I->getOperand(0), Ty),
267 I->getOperand(1), Name);
271 assert(0 && "Expression convertable, but don't know how to convert?");
275 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
276 assert(It != BIL.end() && "Instruction not in own basic block??");
279 //cerr << "RInst: " << Res << "BB After: " << BB << endl << endl;
286 // DoInsertArrayCast - If the argument value has a pointer type, and if the
287 // argument value is used as an array, insert a cast before the specified
288 // basic block iterator that casts the value to an array pointer. Return the
289 // new cast instruction (in the CastResult var), or null if no cast is inserted.
291 static bool DoInsertArrayCast(Method *CurMeth, Value *V, BasicBlock *BB,
292 BasicBlock::iterator &InsertBefore,
293 CastInst *&CastResult) {
294 const PointerType *ThePtrType = dyn_cast<PointerType>(V->getType());
295 if (!ThePtrType) return false;
296 bool InsertCast = false;
298 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
299 Instruction *Inst = cast<Instruction>(*I);
300 switch (Inst->getOpcode()) {
301 default: break; // Not an interesting use...
302 case Instruction::Add: // It's being used as an array index!
303 //case Instruction::Sub:
306 case Instruction::Cast: // There is already a cast instruction!
307 if (const PointerType *PT = dyn_cast<const PointerType>(Inst->getType()))
308 if (const ArrayType *AT = dyn_cast<const ArrayType>(PT->getValueType()))
309 if (AT->getElementType() == ThePtrType->getValueType()) {
310 // Cast already exists! Return the existing one!
311 CastResult = cast<CastInst>(Inst);
312 return false; // No changes made to program though...
318 if (!InsertCast) return false; // There is no reason to insert a cast!
321 const Type *ElTy = ThePtrType->getValueType();
322 const PointerType *DestTy = PointerType::get(ArrayType::get(ElTy));
324 CastResult = new CastInst(V, DestTy);
325 BB->getInstList().insert(InsertBefore, CastResult);
326 //cerr << "Inserted cast: " << CastResult;
327 return true; // Made a change!
331 // DoInsertArrayCasts - Loop over all "incoming" values in the specified method,
332 // inserting a cast for pointer values that are used as arrays. For our
333 // purposes, an incoming value is considered to be either a value that is
334 // either a method parameter, a value created by alloca or malloc, or a value
335 // returned from a function call. All casts are kept attached to their original
336 // values through the PtrCasts map.
338 static bool DoInsertArrayCasts(Method *M, map<Value*, CastInst*> &PtrCasts) {
339 assert(!M->isExternal() && "Can't handle external methods!");
341 // Insert casts for all arguments to the function...
342 bool Changed = false;
343 BasicBlock *CurBB = M->front();
344 BasicBlock::iterator It = CurBB->begin();
345 for (Method::ArgumentListType::iterator AI = M->getArgumentList().begin(),
346 AE = M->getArgumentList().end(); AI != AE; ++AI) {
347 CastInst *TheCast = 0;
348 if (DoInsertArrayCast(M, *AI, CurBB, It, TheCast)) {
349 It = CurBB->begin(); // We might have just invalidated the iterator!
350 Changed = true; // Yes we made a change
351 ++It; // Insert next cast AFTER this one...
354 if (TheCast) // Is there a cast associated with this value?
355 PtrCasts[*AI] = TheCast; // Yes, add it to the map...
358 // TODO: insert casts for alloca, malloc, and function call results. Also,
359 // look for pointers that already have casts, to add to the map.
367 // DoElminatePointerArithmetic - Loop over each incoming pointer variable,
368 // replacing indexing arithmetic with getelementptr calls.
370 static bool DoEliminatePointerArithmetic(const pair<Value*, CastInst*> &Val) {
371 Value *V = Val.first; // The original pointer
372 CastInst *CV = Val.second; // The array casted version of the pointer...
374 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
375 Instruction *Inst = cast<Instruction>(*I);
376 if (Inst->getOpcode() != Instruction::Add)
377 continue; // We only care about add instructions
379 BinaryOperator *Add = cast<BinaryOperator>(Inst);
381 // Make sure the array is the first operand of the add expression...
382 if (Add->getOperand(0) != V)
385 // Get the amount added to the pointer value...
386 Value *AddAmount = Add->getOperand(1);
394 // Peephole Malloc instructions: we take a look at the use chain of the
395 // malloc instruction, and try to find out if the following conditions hold:
396 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
397 // 2. The only users of the malloc are cast instructions
398 // 3. Of the cast instructions, there is only one destination pointer type
399 // [RTy] where the size of the pointed to object is equal to the number
400 // of bytes allocated.
402 // If these conditions hold, we convert the malloc to allocate an [RTy]
403 // element. This should be extended in the future to handle arrays. TODO
405 static bool PeepholeMallocInst(BasicBlock *BB, BasicBlock::iterator &BI) {
406 MallocInst *MI = cast<MallocInst>(*BI);
407 if (!MI->isArrayAllocation()) return false; // No array allocation?
409 ConstPoolUInt *Amt = dyn_cast<ConstPoolUInt>(MI->getArraySize());
410 if (Amt == 0 || MI->getAllocatedType() != ArrayType::get(Type::SByteTy))
413 // Get the number of bytes allocated...
414 unsigned Size = Amt->getValue();
415 const Type *ResultTy = 0;
417 // Loop over all of the uses of the malloc instruction, inspecting casts.
418 for (Value::use_iterator I = MI->use_begin(), E = MI->use_end();
420 if (!isa<CastInst>(*I)) {
421 //cerr << "\tnon" << *I;
422 return false; // A non cast user?
424 CastInst *CI = cast<CastInst>(*I);
425 //cerr << "\t" << CI;
427 // We only work on casts to pointer types for sure, be conservative
428 if (!isa<PointerType>(CI->getType())) {
429 cerr << "Found cast of malloc value to non pointer type:\n" << CI;
433 const Type *DestTy = cast<PointerType>(CI->getType())->getValueType();
434 if (TD.getTypeSize(DestTy) == Size && DestTy != ResultTy) {
435 // Does the size of the allocated type match the number of bytes
439 ResultTy = DestTy; // Keep note of this for future uses...
441 // It's overdefined! We don't know which type to convert to!
447 // If we get this far, we have either found, or not, a type that is cast to
448 // that is of the same size as the malloc instruction.
449 if (!ResultTy) return false;
451 PRINT_PEEPHOLE1("mall-refine:in ", MI);
452 ReplaceInstWithInst(BB->getInstList(), BI,
453 MI = new MallocInst(PointerType::get(ResultTy)));
454 PRINT_PEEPHOLE1("mall-refine:out", MI);
460 static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
461 Instruction *I = *BI;
462 // TODO: replace this with a DCE call
463 if (I->use_size() == 0 && I->getType() != Type::VoidTy) return false;
465 if (CastInst *CI = dyn_cast<CastInst>(I)) {
466 Value *Src = CI->getOperand(0);
467 Instruction *SrcI = dyn_cast<Instruction>(Src); // Nonnull if instr source
468 const Type *DestTy = CI->getType();
470 // Check for a cast of the same type as the destination!
471 if (DestTy == Src->getType()) {
472 PRINT_PEEPHOLE1("cast-of-self-ty", CI);
473 CI->replaceAllUsesWith(Src);
474 if (!Src->hasName() && CI->hasName()) {
475 string Name = CI->getName();
476 CI->setName(""); Src->setName(Name,
477 BB->getParent()->getSymbolTable());
482 // Check for a cast of cast, where no size information is lost...
484 if (CastInst *CSrc = dyn_cast<CastInst>(SrcI))
485 if (isReinterpretingCast(CI) + isReinterpretingCast(CSrc) < 2) {
486 // We can only do c-c elimination if, at most, one cast does a
487 // reinterpretation of the input data.
489 // If legal, make this cast refer the the original casts argument!
491 PRINT_PEEPHOLE2("cast-cast:in ", CI, CSrc);
492 CI->setOperand(0, CSrc->getOperand(0));
493 PRINT_PEEPHOLE1("cast-cast:out", CI);
497 // Check to see if it's a cast of an instruction that does not depend on the
498 // specific type of the operands to do it's job.
499 if (!isReinterpretingCast(CI) &&
500 ExpressionConvertableToType(Src, DestTy)) {
501 PRINT_PEEPHOLE2("EXPR-CONV:in ", CI, Src);
502 CI->setOperand(0, ConvertExpressionToType(Src, DestTy));
503 BI = BB->begin(); // Rescan basic block. BI might be invalidated.
504 PRINT_PEEPHOLE2("EXPR-CONV:out", CI, CI->getOperand(0));
508 } else if (MallocInst *MI = dyn_cast<MallocInst>(I)) {
509 if (PeepholeMallocInst(BB, BI)) return true;
511 } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
512 Value *Val = SI->getOperand(0);
513 Value *Pointer = SI->getPtrOperand();
515 // Peephole optimize the following instructions:
516 // %t1 = getelementptr {<...>} * %StructPtr, <element indices>
517 // store <elementty> %v, <elementty> * %t1
519 // Into: store <elementty> %v, {<...>} * %StructPtr, <element indices>
521 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Pointer)) {
522 PRINT_PEEPHOLE2("gep-store:in", GEP, SI);
523 ReplaceInstWithInst(BB->getInstList(), BI,
524 SI = new StoreInst(Val, GEP->getPtrOperand(),
525 GEP->getIndexVec()));
526 PRINT_PEEPHOLE1("gep-store:out", SI);
530 // Peephole optimize the following instructions:
531 // %t = cast <T1>* %P to <T2> * ;; If T1 is losslessly convertable to T2
532 // store <T2> %V, <T2>* %t
535 // %t = cast <T2> %V to <T1>
536 // store <T1> %t2, <T1>* %P
538 if (CastInst *CI = dyn_cast<CastInst>(Pointer))
539 if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType
540 if (PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
541 if (losslessCastableTypes(Val->getType(), // convertable types!
542 CSPT->getValueType()) &&
543 !SI->hasIndices()) { // No subscripts yet!
544 PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI);
546 // Insert the new T cast instruction... stealing old T's name
547 CastInst *NCI = new CastInst(Val, CSPT->getValueType(),
550 BI = BB->getInstList().insert(BI, NCI)+1;
552 // Replace the old store with a new one!
553 ReplaceInstWithInst(BB->getInstList(), BI,
554 SI = new StoreInst(NCI, CastSrc));
555 PRINT_PEEPHOLE3("st-src-cast:out", NCI, CastSrc, SI);
560 } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
561 Value *Pointer = LI->getPtrOperand();
563 // Peephole optimize the following instructions:
564 // %t1 = getelementptr {<...>} * %StructPtr, <element indices>
565 // %V = load <elementty> * %t1
567 // Into: load {<...>} * %StructPtr, <element indices>
569 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Pointer)) {
570 PRINT_PEEPHOLE2("gep-load:in", GEP, LI);
571 ReplaceInstWithInst(BB->getInstList(), BI,
572 LI = new LoadInst(GEP->getPtrOperand(),
573 GEP->getIndexVec()));
574 PRINT_PEEPHOLE1("gep-load:out", LI);
577 } else if (I->getOpcode() == Instruction::Add &&
578 isa<CastInst>(I->getOperand(1))) {
580 // Peephole optimize the following instructions:
581 // %t1 = cast ulong <const int> to {<...>} *
582 // %t2 = add {<...>} * %SP, %t1 ;; Constant must be 2nd operand
585 // %t1 = cast {<...>}* %SP to int*
586 // %t5 = cast ulong <const int> to int*
587 // %t2 = add int* %t1, %t5 ;; int is same size as field
589 // Into: %t3 = getelementptr {<...>} * %SP, <element indices>
590 // %t2 = cast <eltype> * %t3 to {<...>}*
592 Value *AddOp1 = I->getOperand(0);
593 CastInst *AddOp2 = cast<CastInst>(I->getOperand(1));
594 ConstPoolUInt *OffsetV = dyn_cast<ConstPoolUInt>(AddOp2->getOperand(0));
595 unsigned Offset = OffsetV ? OffsetV->getValue() : 0;
596 Value *SrcPtr; // Of type pointer to struct...
597 const StructType *StructTy;
599 if ((StructTy = getPointedToStruct(AddOp1->getType()))) {
600 SrcPtr = AddOp1; // Handle the first case...
601 } else if (CastInst *AddOp1c = dyn_cast<CastInst>(AddOp1)) {
602 SrcPtr = AddOp1c->getOperand(0); // Handle the second case...
603 StructTy = getPointedToStruct(SrcPtr->getType());
606 // Only proceed if we have detected all of our conditions successfully...
607 if (Offset && StructTy && SrcPtr && Offset < TD.getTypeSize(StructTy)) {
608 const StructLayout *SL = TD.getStructLayout(StructTy);
609 vector<ConstPoolVal*> Offsets;
610 unsigned ActualOffset = Offset;
611 const Type *ElTy = getStructOffsetType(StructTy, ActualOffset, Offsets);
613 if (getPointedToStruct(AddOp1->getType())) { // case 1
614 PRINT_PEEPHOLE2("add-to-gep1:in", AddOp2, I);
616 PRINT_PEEPHOLE3("add-to-gep2:in", AddOp1, AddOp2, I);
619 GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Offsets);
620 BI = BB->getInstList().insert(BI, GEP)+1;
622 assert(Offset-ActualOffset == 0 &&
623 "GEP to middle of element not implemented yet!");
625 ReplaceInstWithInst(BB->getInstList(), BI,
626 I = new CastInst(GEP, I->getType()));
627 PRINT_PEEPHOLE2("add-to-gep:out", GEP, I);
638 static bool DoRaisePass(Method *M) {
639 bool Changed = false;
640 for (Method::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI) {
641 BasicBlock *BB = *MI;
642 BasicBlock::InstListType &BIL = BB->getInstList();
644 for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) {
645 if (PeepholeOptimize(BB, BI))
655 // RaisePointerReferences::doit - Raise a method representation to a higher
658 bool RaisePointerReferences::doit(Method *M) {
659 if (M->isExternal()) return false;
660 bool Changed = false;
662 while (DoRaisePass(M)) Changed = true;
664 // PtrCasts - Keep a mapping between the pointer values (the key of the
665 // map), and the cast to array pointer (the value) in this map. This is
666 // used when converting pointer math into array addressing.
668 map<Value*, CastInst*> PtrCasts;
670 // Insert casts for all incoming pointer values. Keep track of those casts
671 // and the identified incoming values in the PtrCasts map.
673 Changed |= DoInsertArrayCasts(M, PtrCasts);
675 // Loop over each incoming pointer variable, replacing indexing arithmetic
676 // with getelementptr calls.
678 Changed |= reduce_apply_bool(PtrCasts.begin(), PtrCasts.end(),
679 ptr_fun(DoEliminatePointerArithmetic));