//
// This file implements the 'raising' part of the LevelChange API. This is
// useful because, in general, it makes the LLVM code terser and easier to
-// analyze. Note that it is good to run DCE after doing this transformation.
-//
-// Eliminate silly things in the source that do not effect the level, but do
-// clean up the code:
-// * Casts of casts
-// - getelementptr/load & getelementptr/store are folded into a direct
-// load or store
-// - Convert this code (for both alloca and malloc):
-// %reg110 = shl uint %n, ubyte 2 ;;<uint>
-// %reg108 = alloca ubyte, uint %reg110 ;;<ubyte*>
-// %cast76 = cast ubyte* %reg108 to uint* ;;<uint*>
-// To: %cast76 = alloca uint, uint %n
-// Convert explicit addressing to use getelementptr instruction where possible
-// - ...
-//
-// Convert explicit addressing on pointers to use getelementptr instruction.
-// - If a pointer is used by arithmetic operation, insert an array casted
-// version into the source program, only for the following pointer types:
-// * Method argument pointers
-// - Pointers returned by alloca or malloc
-// - Pointers returned by function calls
-// - If a pointer is indexed with a value scaled by a constant size equal
-// to the element size of the array, the expression is replaced with a
-// getelementptr instruction.
+// analyze.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/LevelChange.h"
-#include "llvm/Method.h"
-#include "llvm/Support/STLExtras.h"
+#include "TransformInternals.h"
+#include "llvm/Function.h"
#include "llvm/iOther.h"
#include "llvm/iMemory.h"
-#include "llvm/ConstPoolVals.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Optimizations/ConstantHandling.h"
-#include "llvm/Optimizations/DCE.h"
-#include <map>
+#include "llvm/Constants.h"
+#include "llvm/Pass.h"
+#include "llvm/ConstantHandling.h"
+#include "llvm/Transforms/Scalar/DCE.h"
+#include "llvm/Transforms/Scalar/ConstantProp.h"
+#include "llvm/Analysis/Expressions.h"
+#include "Support/STLExtras.h"
#include <algorithm>
-#include "llvm/Assembly/Writer.h"
-
//#define DEBUG_PEEPHOLE_INSTS 1
#ifdef DEBUG_PEEPHOLE_INSTS
#define PRINT_PEEPHOLE(ID, NUM, I) \
- cerr << "Inst P/H " << ID << "[" << NUM << "] " << I;
+ std::cerr << "Inst P/H " << ID << "[" << NUM << "] " << I;
#else
#define PRINT_PEEPHOLE(ID, NUM, I)
#endif
#define PRINT_PEEPHOLE3(ID, I1, I2, I3) \
do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); \
PRINT_PEEPHOLE(ID, 2, I3); } while (0)
-
-
-// TargetData Hack: Eventually we will have annotations given to us by the
-// backend so that we know stuff about type size and alignments. For now
-// though, just use this, because it happens to match the model that GCC uses.
-//
-const TargetData TD("LevelRaise: Should be GCC though!");
-
-
-// losslessCastableTypes - Return true if the types are bitwise equivalent.
-// This predicate returns true if it is possible to cast from one type to
-// another without gaining or losing precision, or altering the bits in any way.
-//
-static bool losslessCastableTypes(const Type *T1, const Type *T2) {
- if (!T1->isPrimitiveType() && !isa<PointerType>(T1)) return false;
- if (!T2->isPrimitiveType() && !isa<PointerType>(T2)) return false;
-
- if (T1->getPrimitiveID() == T2->getPrimitiveID())
- return true; // Handles identity cast, and cast of differing pointer types
-
- // Now we know that they are two differing primitive or pointer types
- switch (T1->getPrimitiveID()) {
- case Type::UByteTyID: return T2 == Type::SByteTy;
- case Type::SByteTyID: return T2 == Type::UByteTy;
- case Type::UShortTyID: return T2 == Type::ShortTy;
- case Type::ShortTyID: return T2 == Type::UShortTy;
- case Type::UIntTyID: return T2 == Type::IntTy;
- case Type::IntTyID: return T2 == Type::UIntTy;
- case Type::ULongTyID:
- case Type::LongTyID:
- case Type::PointerTyID:
- return T2 == Type::ULongTy || T2 == Type::LongTy ||
- T2->getPrimitiveID() == Type::PointerTyID;
- default:
- return false; // Other types have no identity values
- }
-}
+#define PRINT_PEEPHOLE4(ID, I1, I2, I3, I4) \
+ do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); \
+ PRINT_PEEPHOLE(ID, 2, I3); PRINT_PEEPHOLE(ID, 3, I4); } while (0)
// isReinterpretingCast - Return true if the cast instruction specified will
// cast instruction would cause the underlying bits to change.
//
static inline bool isReinterpretingCast(const CastInst *CI) {
- return !losslessCastableTypes(CI->getOperand(0)->getType(), CI->getType());
-}
-
-
-// getPointedToStruct - If the argument is a pointer type, and the pointed to
-// value is a struct type, return the struct type, else return null.
-//
-static const StructType *getPointedToStruct(const Type *Ty) {
- const PointerType *PT = dyn_cast<PointerType>(Ty);
- return PT ? dyn_cast<StructType>(PT->getValueType()) : 0;
-}
-
-
-// getStructOffsetType - Return a vector of offsets that are to be used to index
-// into the specified struct type to get as close as possible to index as we
-// can. Note that it is possible that we cannot get exactly to Offset, in which
-// case we update offset to be the offset we actually obtained. The resultant
-// leaf type is returned.
-//
-static const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
- vector<ConstPoolVal*> &Offsets) {
- if (!isa<StructType>(Ty)) {
- Offset = 0; // Return the offset that we were able to acheive
- return Ty; // Return the leaf type
- }
-
- assert(Offset < TD.getTypeSize(Ty) && "Offset not in struct!");
- const StructType *STy = cast<StructType>(Ty);
- const StructLayout *SL = TD.getStructLayout(STy);
-
- // This loop terminates always on a 0 <= i < MemberOffsets.size()
- unsigned i;
- for (i = 0; i < SL->MemberOffsets.size()-1; ++i)
- if (Offset >= SL->MemberOffsets[i] && Offset < SL->MemberOffsets[i+1])
- break;
-
- assert(Offset >= SL->MemberOffsets[i] &&
- (i == SL->MemberOffsets.size()-1 || Offset < SL->MemberOffsets[i+1]));
-
- // Make sure to save the current index...
- Offsets.push_back(ConstPoolUInt::get(Type::UByteTy, i));
-
- unsigned SubOffs = Offset - SL->MemberOffsets[i];
- const Type *LeafTy = getStructOffsetType(STy->getElementTypes()[i], SubOffs,
- Offsets);
- Offset = SL->MemberOffsets[i] + SubOffs;
- return LeafTy;
+ return!CI->getOperand(0)->getType()->isLosslesslyConvertableTo(CI->getType());
}
-// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
-// with a value, then remove and delete the original instruction.
+// Peephole optimize the following instructions:
+// %t1 = cast ? to x *
+// %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand
//
-static void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
- BasicBlock::iterator &BI, Value *V) {
- Instruction *I = *BI;
- // Replaces all of the uses of the instruction with uses of the value
- I->replaceAllUsesWith(V);
-
- // Remove the unneccesary instruction now...
- BIL.remove(BI);
-
- // Make sure to propogate a name if there is one already...
- if (I->hasName() && !V->hasName())
- V->setName(I->getName(), BIL.getParent()->getSymbolTable());
-
- // Remove the dead instruction now...
- delete I;
-}
-
-
-// ReplaceInstWithInst - Replace the instruction specified by BI with the
-// instruction specified by I. The original instruction is deleted and BI is
-// updated to point to the new instruction.
+// Into: %t3 = getelementptr {<...>} * %SP, <element indices>
+// %t2 = cast <eltype> * %t3 to {<...>}*
//
-static void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
- BasicBlock::iterator &BI, Instruction *I) {
- assert(I->getParent() == 0 &&
- "ReplaceInstWithInst: Instruction already inserted into basic block!");
-
- // Insert the new instruction into the basic block...
- BI = BIL.insert(BI, I)+1;
-
- // Replace all uses of the old instruction, and delete it.
- ReplaceInstWithValue(BIL, BI, I);
-
- // Reexamine the instruction just inserted next time around the cleanup pass
- // loop.
- --BI;
-}
+static bool HandleCastToPointer(BasicBlock::iterator BI,
+ const PointerType *DestPTy) {
+ CastInst *CI = cast<CastInst>(*BI);
+ if (CI->use_empty()) return false;
-
-// ExpressionConvertableToType - Return true if it is possible
-static bool ExpressionConvertableToType(Value *V, const Type *Ty) {
- Instruction *I = dyn_cast<Instruction>(V);
- if (I == 0) {
- // It's not an instruction, check to see if it's a constant... all constants
- // can be converted to an equivalent value (except pointers, they can't be
- // const prop'd in general).
- //
- if (isa<ConstPoolVal>(V) &&
- !isa<PointerType>(V->getType()) && !isa<PointerType>(Ty)) return true;
-
- return false; // Otherwise, we can't convert!
- }
- if (I->getType() == Ty) return false; // Expression already correct type!
-
- switch (I->getOpcode()) {
- case Instruction::Cast:
- // We can convert the expr if the cast destination type is losslessly
- // convertable to the requested type.
- return losslessCastableTypes(Ty, I->getType());
-
- case Instruction::Add:
- case Instruction::Sub:
- return ExpressionConvertableToType(I->getOperand(0), Ty) &&
- ExpressionConvertableToType(I->getOperand(1), Ty);
- case Instruction::Shl:
- return ExpressionConvertableToType(I->getOperand(0), Ty);
- case Instruction::Shr:
- if (Ty->isSigned() != V->getType()->isSigned()) return false;
- return ExpressionConvertableToType(I->getOperand(0), Ty);
-
- case Instruction::Load: {
- LoadInst *LI = cast<LoadInst>(I);
- if (LI->hasIndices()) return false;
- return ExpressionConvertableToType(LI->getPtrOperand(),
- PointerType::get(Ty));
- }
- case Instruction::GetElementPtr: {
- // GetElementPtr's are directly convertable to a pointer type if they have
- // a number of zeros at the end. Because removing these values does not
- // change the logical offset of the GEP, it is okay and fair to remove them.
- // This can change this:
- // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
- // %t2 = cast %List * * %t1 to %List *
- // into
- // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
- //
- GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
- const PointerType *PTy = dyn_cast<PointerType>(Ty);
- if (!PTy) return false;
-
- // Check to see if there are zero elements that we can remove from the
- // index array. If there are, check to see if removing them causes us to
- // get to the right type...
- //
- vector<ConstPoolVal*> Indices = GEP->getIndexVec();
- const Type *BaseType = GEP->getPtrOperand()->getType();
-
- while (Indices.size() &&
- cast<ConstPoolUInt>(Indices.back())->getValue() == 0) {
- Indices.pop_back();
- const Type *ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices,
- true);
- if (ElTy == PTy->getValueType())
- return true; // Found a match!!
+ // Scan all of the uses, looking for any uses that are not add
+ // instructions. If we have non-adds, do not make this transformation.
+ //
+ for (Value::use_iterator I = CI->use_begin(), E = CI->use_end();
+ I != E; ++I) {
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(*I)) {
+ if (BO->getOpcode() != Instruction::Add)
+ return false;
+ } else {
+ return false;
}
- break; // No match, maybe next time.
- }
}
- return false;
-}
-
-
-static Value *ConvertExpressionToType(Value *V, const Type *Ty) {
- assert(ExpressionConvertableToType(V, Ty) && "Value is not convertable!");
- Instruction *I = dyn_cast<Instruction>(V);
- if (I == 0)
- if (ConstPoolVal *CPV = cast<ConstPoolVal>(V)) {
- // Constants are converted by constant folding the cast that is required.
- // We assume here that all casts are implemented for constant prop.
- Value *Result = opt::ConstantFoldCastInstruction(CPV, Ty);
- if (!Result) cerr << "Couldn't fold " << CPV << " to " << Ty << endl;
- assert(Result && "ConstantFoldCastInstruction Failed!!!");
- return Result;
- }
+ std::vector<Value*> Indices;
+ Value *Src = CI->getOperand(0);
+ const Type *Result = ConvertableToGEP(DestPTy, Src, Indices, &BI);
+ if (Result == 0) return false; // Not convertable...
- BasicBlock *BB = I->getParent();
- BasicBlock::InstListType &BIL = BB->getInstList();
- string Name = I->getName(); if (!Name.empty()) I->setName("");
- Instruction *Res; // Result of conversion
+ PRINT_PEEPHOLE2("cast-add-to-gep:in", Src, CI);
- //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
-
- switch (I->getOpcode()) {
- case Instruction::Cast:
- Res = new CastInst(I->getOperand(0), Ty, Name);
- break;
+ // If we have a getelementptr capability... transform all of the
+ // add instruction uses into getelementptr's.
+ while (!CI->use_empty()) {
+ BinaryOperator *I = cast<BinaryOperator>(*CI->use_begin());
+ assert(I->getOpcode() == Instruction::Add && I->getNumOperands() == 2 &&
+ "Use is not a valid add instruction!");
- case Instruction::Add:
- case Instruction::Sub:
- Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
- ConvertExpressionToType(I->getOperand(0), Ty),
- ConvertExpressionToType(I->getOperand(1), Ty),
- Name);
- break;
-
- case Instruction::Shl:
- case Instruction::Shr:
- Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(),
- ConvertExpressionToType(I->getOperand(0), Ty),
- I->getOperand(1), Name);
- break;
-
- case Instruction::Load: {
- LoadInst *LI = cast<LoadInst>(I);
- assert(!LI->hasIndices());
- Res = new LoadInst(ConvertExpressionToType(LI->getPtrOperand(),
- PointerType::get(Ty)), Name);
- break;
- }
-
- case Instruction::GetElementPtr: {
- // GetElementPtr's are directly convertable to a pointer type if they have
- // a number of zeros at the end. Because removing these values does not
- // change the logical offset of the GEP, it is okay and fair to remove them.
- // This can change this:
- // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
- // %t2 = cast %List * * %t1 to %List *
- // into
- // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
- //
- GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
-
- // Check to see if there are zero elements that we can remove from the
- // index array. If there are, check to see if removing them causes us to
- // get to the right type...
- //
- vector<ConstPoolVal*> Indices = GEP->getIndexVec();
- const Type *BaseType = GEP->getPtrOperand()->getType();
- const Type *PVTy = cast<PointerType>(Ty)->getValueType();
- Res = 0;
- while (Indices.size() &&
- cast<ConstPoolUInt>(Indices.back())->getValue() == 0) {
- Indices.pop_back();
- if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
- if (Indices.size() == 0) {
- Res = new CastInst(GEP->getPtrOperand(), BaseType); // NOOP
- } else {
- Res = new GetElementPtrInst(GEP->getPtrOperand(), Indices, Name);
- }
- break;
- }
- }
- assert(Res && "Didn't find match!");
- break; // No match, maybe next time.
- }
-
- default:
- assert(0 && "Expression convertable, but don't know how to convert?");
- return 0;
- }
-
- BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
- assert(It != BIL.end() && "Instruction not in own basic block??");
- BIL.insert(It, Res);
-
- //cerr << "RInst: " << Res << "BB After: " << BB << endl << endl;
-
- return Res;
-}
-
-
-
-// DoInsertArrayCast - If the argument value has a pointer type, and if the
-// argument value is used as an array, insert a cast before the specified
-// basic block iterator that casts the value to an array pointer. Return the
-// new cast instruction (in the CastResult var), or null if no cast is inserted.
-//
-static bool DoInsertArrayCast(Method *CurMeth, Value *V, BasicBlock *BB,
- BasicBlock::iterator &InsertBefore,
- CastInst *&CastResult) {
- const PointerType *ThePtrType = dyn_cast<PointerType>(V->getType());
- if (!ThePtrType) return false;
- bool InsertCast = false;
-
- for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
- Instruction *Inst = cast<Instruction>(*I);
- switch (Inst->getOpcode()) {
- default: break; // Not an interesting use...
- case Instruction::Add: // It's being used as an array index!
- //case Instruction::Sub:
- InsertCast = true;
- break;
- case Instruction::Cast: // There is already a cast instruction!
- if (const PointerType *PT = dyn_cast<const PointerType>(Inst->getType()))
- if (const ArrayType *AT = dyn_cast<const ArrayType>(PT->getValueType()))
- if (AT->getElementType() == ThePtrType->getValueType()) {
- // Cast already exists! Return the existing one!
- CastResult = cast<CastInst>(Inst);
- return false; // No changes made to program though...
- }
- break;
- }
- }
-
- if (!InsertCast) return false; // There is no reason to insert a cast!
-
- // Insert a cast!
- const Type *ElTy = ThePtrType->getValueType();
- const PointerType *DestTy = PointerType::get(ArrayType::get(ElTy));
-
- CastResult = new CastInst(V, DestTy);
- BB->getInstList().insert(InsertBefore, CastResult);
- //cerr << "Inserted cast: " << CastResult;
- return true; // Made a change!
-}
+ // Get the value added to the cast result pointer...
+ Value *OtherPtr = I->getOperand((I->getOperand(0) == CI) ? 1 : 0);
+
+ Instruction *GEP = new GetElementPtrInst(OtherPtr, Indices, I->getName());
+ PRINT_PEEPHOLE1("cast-add-to-gep:i", I);
+
+ if (GEP->getType() == I->getType()) {
+ // Replace the old add instruction with the shiny new GEP inst
+ ReplaceInstWithInst(I, GEP);
+ } else {
+ // If the type produced by the gep instruction differs from the original
+ // add instruction type, insert a cast now.
+ //
+ // Insert the GEP instruction before the old add instruction... and get an
+ // iterator to point at the add instruction...
+ BasicBlock::iterator GEPI = InsertInstBeforeInst(GEP, I)+1;
-// DoInsertArrayCasts - Loop over all "incoming" values in the specified method,
-// inserting a cast for pointer values that are used as arrays. For our
-// purposes, an incoming value is considered to be either a value that is
-// either a method parameter, a value created by alloca or malloc, or a value
-// returned from a function call. All casts are kept attached to their original
-// values through the PtrCasts map.
-//
-static bool DoInsertArrayCasts(Method *M, map<Value*, CastInst*> &PtrCasts) {
- assert(!M->isExternal() && "Can't handle external methods!");
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP);
+ CastInst *CI = new CastInst(GEP, I->getType());
+ GEP = CI;
- // Insert casts for all arguments to the function...
- bool Changed = false;
- BasicBlock *CurBB = M->front();
- BasicBlock::iterator It = CurBB->begin();
- for (Method::ArgumentListType::iterator AI = M->getArgumentList().begin(),
- AE = M->getArgumentList().end(); AI != AE; ++AI) {
- CastInst *TheCast = 0;
- if (DoInsertArrayCast(M, *AI, CurBB, It, TheCast)) {
- It = CurBB->begin(); // We might have just invalidated the iterator!
- Changed = true; // Yes we made a change
- ++It; // Insert next cast AFTER this one...
+ // Replace the old add instruction with the shiny new GEP inst
+ ReplaceInstWithInst(I->getParent()->getInstList(), GEPI, GEP);
}
- if (TheCast) // Is there a cast associated with this value?
- PtrCasts[*AI] = TheCast; // Yes, add it to the map...
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP);
}
-
- // TODO: insert casts for alloca, malloc, and function call results. Also,
- // look for pointers that already have casts, to add to the map.
-
- return Changed;
+ return true;
}
-
-
-
-// DoElminatePointerArithmetic - Loop over each incoming pointer variable,
-// replacing indexing arithmetic with getelementptr calls.
+// Peephole optimize the following instructions:
+// %t1 = cast ulong <const int> to {<...>} *
+// %t2 = add {<...>} * %SP, %t1 ;; Constant must be 2nd operand
//
-static bool DoEliminatePointerArithmetic(const pair<Value*, CastInst*> &Val) {
- Value *V = Val.first; // The original pointer
- CastInst *CV = Val.second; // The array casted version of the pointer...
-
- for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
- Instruction *Inst = cast<Instruction>(*I);
- if (Inst->getOpcode() != Instruction::Add)
- continue; // We only care about add instructions
-
- BinaryOperator *Add = cast<BinaryOperator>(Inst);
-
- // Make sure the array is the first operand of the add expression...
- if (Add->getOperand(0) != V)
- Add->swapOperands();
-
- // Get the amount added to the pointer value...
- Value *AddAmount = Add->getOperand(1);
-
-
- }
- return false;
-}
-
-
-// Peephole Malloc instructions: we take a look at the use chain of the
-// malloc instruction, and try to find out if the following conditions hold:
-// 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
-// 2. The only users of the malloc are cast instructions
-// 3. Of the cast instructions, there is only one destination pointer type
-// [RTy] where the size of the pointed to object is equal to the number
-// of bytes allocated.
+// or
+// %t1 = cast {<...>}* %SP to int*
+// %t5 = cast ulong <const int> to int*
+// %t2 = add int* %t1, %t5 ;; int is same size as field
//
-// If these conditions hold, we convert the malloc to allocate an [RTy]
-// element. This should be extended in the future to handle arrays. TODO
+// Into: %t3 = getelementptr {<...>} * %SP, <element indices>
+// %t2 = cast <eltype> * %t3 to {<...>}*
//
-static bool PeepholeMallocInst(BasicBlock *BB, BasicBlock::iterator &BI) {
- MallocInst *MI = cast<MallocInst>(*BI);
- if (!MI->isArrayAllocation()) return false; // No array allocation?
+static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI,
+ Value *AddOp1, CastInst *AddOp2) {
+ const CompositeType *CompTy;
+ Value *OffsetVal = AddOp2->getOperand(0);
+ Value *SrcPtr; // Of type pointer to struct...
+
+ if ((CompTy = getPointedToComposite(AddOp1->getType()))) {
+ SrcPtr = AddOp1; // Handle the first case...
+ } else if (CastInst *AddOp1c = dyn_cast<CastInst>(AddOp1)) {
+ SrcPtr = AddOp1c->getOperand(0); // Handle the second case...
+ CompTy = getPointedToComposite(SrcPtr->getType());
+ }
- ConstPoolUInt *Amt = dyn_cast<ConstPoolUInt>(MI->getArraySize());
- if (Amt == 0 || MI->getAllocatedType() != ArrayType::get(Type::SByteTy))
+ // Only proceed if we have detected all of our conditions successfully...
+ if (!CompTy || !SrcPtr || !OffsetVal->getType()->isIntegral())
return false;
- // Get the number of bytes allocated...
- unsigned Size = Amt->getValue();
- const Type *ResultTy = 0;
+ std::vector<Value*> Indices;
+ if (!ConvertableToGEP(SrcPtr->getType(), OffsetVal, Indices, &BI))
+ return false; // Not convertable... perhaps next time
- // Loop over all of the uses of the malloc instruction, inspecting casts.
- for (Value::use_iterator I = MI->use_begin(), E = MI->use_end();
- I != E; ++I) {
- if (!isa<CastInst>(*I)) {
- //cerr << "\tnon" << *I;
- return false; // A non cast user?
- }
- CastInst *CI = cast<CastInst>(*I);
- //cerr << "\t" << CI;
-
- // We only work on casts to pointer types for sure, be conservative
- if (!isa<PointerType>(CI->getType())) {
- cerr << "Found cast of malloc value to non pointer type:\n" << CI;
- return false;
- }
-
- const Type *DestTy = cast<PointerType>(CI->getType())->getValueType();
- if (TD.getTypeSize(DestTy) == Size && DestTy != ResultTy) {
- // Does the size of the allocated type match the number of bytes
- // allocated?
- //
- if (ResultTy == 0) {
- ResultTy = DestTy; // Keep note of this for future uses...
- } else {
- // It's overdefined! We don't know which type to convert to!
- return false;
- }
- }
+ if (getPointedToComposite(AddOp1->getType())) { // case 1
+ PRINT_PEEPHOLE2("add-to-gep1:in", AddOp2, *BI);
+ } else {
+ PRINT_PEEPHOLE3("add-to-gep2:in", AddOp1, AddOp2, *BI);
}
- // If we get this far, we have either found, or not, a type that is cast to
- // that is of the same size as the malloc instruction.
- if (!ResultTy) return false;
+ GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Indices,
+ AddOp2->getName());
+ BI = BB->getInstList().insert(BI, GEP)+1;
- PRINT_PEEPHOLE1("mall-refine:in ", MI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- MI = new MallocInst(PointerType::get(ResultTy)));
- PRINT_PEEPHOLE1("mall-refine:out", MI);
+ Instruction *NCI = new CastInst(GEP, AddOp1->getType());
+ ReplaceInstWithInst(BB->getInstList(), BI, NCI);
+ PRINT_PEEPHOLE2("add-to-gep:out", GEP, NCI);
return true;
}
-
-// Peephole optimize the following instructions:
-// %t1 = cast int (uint) * %reg111 to uint (...) *
-// %t2 = call uint (...) * %cast111( uint %key )
-//
-// Into: %t3 = call int (uint) * %reg111( uint %key )
-// %t2 = cast int %t3 to uint
-//
-static bool PeepholeCallInst(BasicBlock *BB, BasicBlock::iterator &BI) {
- CallInst *CI = cast<CallInst>(*BI);
- return false;
-}
-
-
static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
Instruction *I = *BI;
PRINT_PEEPHOLE1("cast-of-self-ty", CI);
CI->replaceAllUsesWith(Src);
if (!Src->hasName() && CI->hasName()) {
- string Name = CI->getName();
- CI->setName(""); Src->setName(Name,
- BB->getParent()->getSymbolTable());
+ std::string Name = CI->getName();
+ CI->setName("");
+ Src->setName(Name, BB->getParent()->getSymbolTable());
}
return true;
}
// Peephole optimize the following instructions:
// %tmp = cast <ty> %V to <ty2>
- // %V = cast <ty2> %tmp to <ty3> ; Where ty & ty2 are same size
+ // %V = cast <ty2> %tmp to <ty3> ; Where ty & ty2 are same size
//
// Into: cast <ty> %V to <ty3>
//
// Check to see if it's a cast of an instruction that does not depend on the
// specific type of the operands to do it's job.
- if (!isReinterpretingCast(CI) &&
- ExpressionConvertableToType(Src, DestTy)) {
- PRINT_PEEPHOLE2("EXPR-CONV:in ", CI, Src);
- CI->setOperand(0, ConvertExpressionToType(Src, DestTy));
- BI = BB->begin(); // Rescan basic block. BI might be invalidated.
- PRINT_PEEPHOLE2("EXPR-CONV:out", CI, CI->getOperand(0));
- return true;
+ if (!isReinterpretingCast(CI)) {
+ ValueTypeCache ConvertedTypes;
+
+ // Check to see if we can convert the users of the cast value to match the
+ // source type of the cast...
+ //
+ ConvertedTypes[CI] = CI->getType(); // Make sure the cast doesn't change
+ if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) {
+ PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", Src, CI, BB->getParent());
+
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "\nCONVERTING SRC EXPR TYPE:\n";
+#endif
+ ValueMapCache ValueMap;
+ Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
+ if (Constant *CPV = dyn_cast<Constant>(E))
+ CI->replaceAllUsesWith(CPV);
+
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "DONE CONVERTING SRC EXPR TYPE: \n" << BB->getParent();
+#endif
+ return true;
+ }
+
+ // Check to see if we can convert the source of the cast to match the
+ // destination type of the cast...
+ //
+ ConvertedTypes.clear();
+ if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) {
+ PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", Src, CI, BB->getParent());
+
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "\nCONVERTING EXPR TYPE:\n";
+#endif
+ ValueMapCache ValueMap;
+ ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI!
+
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src);
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "DONE CONVERTING EXPR TYPE: \n\n" << BB->getParent();
+#endif
+ return true;
+ }
+ }
+
+ // Otherwise find out it this cast is a cast to a pointer type, which is
+ // then added to some other pointer, then loaded or stored through. If
+ // so, convert the add into a getelementptr instruction...
+ //
+ if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) {
+ if (HandleCastToPointer(BI, DestPTy)) {
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ return true;
+ }
}
// Check to see if we are casting from a structure pointer to a pointer to
// Into: %t2 = getelementptr {<...>} * %StructPtr, <0, 0, 0, ...>
// %t1 = cast <eltype> * %t1 to <ty> *
//
- if (const StructType *STy = getPointedToStruct(Src->getType()))
+#if 1
+ if (const CompositeType *CTy = getPointedToComposite(Src->getType()))
if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) {
// Loop over uses of the cast, checking for add instructions. If an add
// type.
//
if (!HasAddUse) {
- const Type *DestPointedTy = DestPTy->getValueType();
+ const Type *DestPointedTy = DestPTy->getElementType();
unsigned Depth = 1;
- const StructType *CurSTy = STy;
+ const CompositeType *CurCTy = CTy;
const Type *ElTy = 0;
- while (CurSTy) {
-
- // Check for a zero element struct type... if we have one, bail.
- if (CurSTy->getElementTypes().size() == 0) break;
+
+ // Build the index vector, full of all zeros
+ std::vector<Value*> Indices;
+ Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
+ while (CurCTy && !isa<PointerType>(CurCTy)) {
+ if (const StructType *CurSTy = dyn_cast<StructType>(CurCTy)) {
+ // Check for a zero element struct type... if we have one, bail.
+ if (CurSTy->getElementTypes().size() == 0) break;
- // Grab the first element of the struct type, which must lie at
- // offset zero in the struct.
- //
- ElTy = CurSTy->getElementTypes()[0];
+ // Grab the first element of the struct type, which must lie at
+ // offset zero in the struct.
+ //
+ ElTy = CurSTy->getElementTypes()[0];
+ } else {
+ ElTy = cast<ArrayType>(CurCTy)->getElementType();
+ }
+
+ // Insert a zero to index through this type...
+ Indices.push_back(ConstantUInt::get(CurCTy->getIndexType(), 0));
// Did we find what we're looking for?
- if (losslessCastableTypes(ElTy, DestPointedTy)) break;
+ if (ElTy->isLosslesslyConvertableTo(DestPointedTy)) break;
// Nope, go a level deeper.
++Depth;
- CurSTy = dyn_cast<StructType>(ElTy);
+ CurCTy = dyn_cast<CompositeType>(ElTy);
ElTy = 0;
}
if (ElTy) {
PRINT_PEEPHOLE1("cast-for-first:in", CI);
- // Build the index vector, full of all zeros
- vector<ConstPoolVal *> Indices(Depth,
- ConstPoolUInt::get(Type::UByteTy,0));
-
// Insert the new T cast instruction... stealing old T's name
GetElementPtrInst *GEP = new GetElementPtrInst(Src, Indices,
CI->getName());
}
}
}
+#endif
-
- } else if (MallocInst *MI = dyn_cast<MallocInst>(I)) {
- if (PeepholeMallocInst(BB, BI)) return true;
-
- } else if (CallInst *CI = dyn_cast<CallInst>(I)) {
- if (PeepholeCallInst(BB, BI)) return true;
-
+#if 1
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
Value *Val = SI->getOperand(0);
- Value *Pointer = SI->getPtrOperand();
-
- // Peephole optimize the following instructions:
- // %t1 = getelementptr {<...>} * %StructPtr, <element indices>
- // store <elementty> %v, <elementty> * %t1
- //
- // Into: store <elementty> %v, {<...>} * %StructPtr, <element indices>
- //
- if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Pointer)) {
- PRINT_PEEPHOLE2("gep-store:in", GEP, SI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- SI = new StoreInst(Val, GEP->getPtrOperand(),
- GEP->getIndexVec()));
- PRINT_PEEPHOLE1("gep-store:out", SI);
- return true;
- }
+ Value *Pointer = SI->getPointerOperand();
// Peephole optimize the following instructions:
// %t = cast <T1>* %P to <T2> * ;; If T1 is losslessly convertable to T2
// %t = cast <T2> %V to <T1>
// store <T1> %t2, <T1>* %P
//
+ // Note: This is not taken care of by expr conversion because there might
+ // not be a cast available for the store to convert the incoming value of.
+ // This code is basically here to make sure that pointers don't have casts
+ // if possible.
+ //
if (CastInst *CI = dyn_cast<CastInst>(Pointer))
if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType
if (PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
- if (losslessCastableTypes(Val->getType(), // convertable types!
- CSPT->getValueType()) &&
+ // convertable types?
+ if (Val->getType()->isLosslesslyConvertableTo(CSPT->getElementType()) &&
!SI->hasIndices()) { // No subscripts yet!
PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI);
// Insert the new T cast instruction... stealing old T's name
- CastInst *NCI = new CastInst(Val, CSPT->getValueType(),
+ CastInst *NCI = new CastInst(Val, CSPT->getElementType(),
CI->getName());
CI->setName("");
BI = BB->getInstList().insert(BI, NCI)+1;
return true;
}
-
- } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
- Value *Pointer = LI->getPtrOperand();
-
- // Peephole optimize the following instructions:
- // %t1 = getelementptr {<...>} * %StructPtr, <element indices>
- // %V = load <elementty> * %t1
- //
- // Into: load {<...>} * %StructPtr, <element indices>
- //
- if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Pointer)) {
- PRINT_PEEPHOLE2("gep-load:in", GEP, LI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- LI = new LoadInst(GEP->getPtrOperand(),
- GEP->getIndexVec()));
- PRINT_PEEPHOLE1("gep-load:out", LI);
- return true;
- }
} else if (I->getOpcode() == Instruction::Add &&
isa<CastInst>(I->getOperand(1))) {
- // Peephole optimize the following instructions:
- // %t1 = cast ulong <const int> to {<...>} *
- // %t2 = add {<...>} * %SP, %t1 ;; Constant must be 2nd operand
- //
- // or
- // %t1 = cast {<...>}* %SP to int*
- // %t5 = cast ulong <const int> to int*
- // %t2 = add int* %t1, %t5 ;; int is same size as field
- //
- // Into: %t3 = getelementptr {<...>} * %SP, <element indices>
- // %t2 = cast <eltype> * %t3 to {<...>}*
- //
- Value *AddOp1 = I->getOperand(0);
- CastInst *AddOp2 = cast<CastInst>(I->getOperand(1));
- ConstPoolUInt *OffsetV = dyn_cast<ConstPoolUInt>(AddOp2->getOperand(0));
- unsigned Offset = OffsetV ? OffsetV->getValue() : 0;
- Value *SrcPtr; // Of type pointer to struct...
- const StructType *StructTy;
-
- if ((StructTy = getPointedToStruct(AddOp1->getType()))) {
- SrcPtr = AddOp1; // Handle the first case...
- } else if (CastInst *AddOp1c = dyn_cast<CastInst>(AddOp1)) {
- SrcPtr = AddOp1c->getOperand(0); // Handle the second case...
- StructTy = getPointedToStruct(SrcPtr->getType());
- }
-
- // Only proceed if we have detected all of our conditions successfully...
- if (Offset && StructTy && SrcPtr && Offset < TD.getTypeSize(StructTy)) {
- const StructLayout *SL = TD.getStructLayout(StructTy);
- vector<ConstPoolVal*> Offsets;
- unsigned ActualOffset = Offset;
- const Type *ElTy = getStructOffsetType(StructTy, ActualOffset, Offsets);
-
- if (getPointedToStruct(AddOp1->getType())) { // case 1
- PRINT_PEEPHOLE2("add-to-gep1:in", AddOp2, I);
- } else {
- PRINT_PEEPHOLE3("add-to-gep2:in", AddOp1, AddOp2, I);
- }
-
- GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Offsets);
- BI = BB->getInstList().insert(BI, GEP)+1;
-
- assert(Offset-ActualOffset == 0 &&
- "GEP to middle of element not implemented yet!");
-
- ReplaceInstWithInst(BB->getInstList(), BI,
- I = new CastInst(GEP, I->getType()));
- PRINT_PEEPHOLE2("add-to-gep:out", GEP, I);
+ if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0),
+ cast<CastInst>(I->getOperand(1))))
return true;
- }
+
+#endif
}
return false;
-static bool DoRaisePass(Method *M) {
+static bool DoRaisePass(Function *F) {
bool Changed = false;
- for (Method::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI) {
+ for (Function::iterator MI = F->begin(), ME = F->end(); MI != ME; ++MI) {
BasicBlock *BB = *MI;
BasicBlock::InstListType &BIL = BB->getInstList();
for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) {
- if (opt::DeadCodeElimination::dceInstruction(BIL, BI) ||
- PeepholeOptimize(BB, BI))
+#if DEBUG_PEEPHOLE_INSTS
+ cerr << "Processing: " << *BI;
+#endif
+ if (dceInstruction(BIL, BI) || doConstantPropogation(BB, BI)) {
+ Changed = true;
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "***\t\t^^-- DeadCode Elinated!\n";
+#endif
+ } else if (PeepholeOptimize(BB, BI))
Changed = true;
else
++BI;
}
-// RaisePointerReferences::doit - Raise a method representation to a higher
+// RaisePointerReferences::doit - Raise a function representation to a higher
// level.
//
-bool RaisePointerReferences::doit(Method *M) {
- if (M->isExternal()) return false;
- bool Changed = false;
+static bool doRPR(Function *F) {
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "\n\n\nStarting to work on Function '" << F->getName() << "'\n";
+#endif
+ // Insert casts for all incoming pointer pointer values that are treated as
+ // arrays...
+ //
+ bool Changed = false, LocalChange;
+
+ do {
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\n\n\nStarting to work on Method '" << M->getName() << "'\n";
+ cerr << "Looping: \n" << F;
#endif
- while (DoRaisePass(M)) Changed = true;
+ // Iterate over the function, refining it, until it converges on a stable
+ // state
+ LocalChange = false;
+ while (DoRaisePass(F)) LocalChange = true;
+ Changed |= LocalChange;
- // PtrCasts - Keep a mapping between the pointer values (the key of the
- // map), and the cast to array pointer (the value) in this map. This is
- // used when converting pointer math into array addressing.
- //
- map<Value*, CastInst*> PtrCasts;
+ } while (LocalChange);
- // Insert casts for all incoming pointer values. Keep track of those casts
- // and the identified incoming values in the PtrCasts map.
- //
- Changed |= DoInsertArrayCasts(M, PtrCasts);
+ return Changed;
+}
- // Loop over each incoming pointer variable, replacing indexing arithmetic
- // with getelementptr calls.
- //
- Changed |= reduce_apply_bool(PtrCasts.begin(), PtrCasts.end(),
- ptr_fun(DoEliminatePointerArithmetic));
+namespace {
+ struct RaisePointerReferences : public FunctionPass {
+ const char *getPassName() const { return "Raise Pointer References"; }
- return Changed;
+ virtual bool runOnFunction(Function *F) { return doRPR(F); }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.preservesCFG();
+ }
+ };
+}
+
+Pass *createRaisePointerReferencesPass() {
+ return new RaisePointerReferences();
}
+
+
projects / oota-llvm.git / blobdiff