Clean up code, implement array indexing stuff
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1340 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/LevelRaise.cpp b/lib/Transforms/LevelRaise.cpp
index 78bb2eb..3472dec 100644
--- a/lib/Transforms/LevelRaise.cpp
+++ b/lib/Transforms/LevelRaise.cpp
@@ -2,30 +2,7 @@
//
// 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.
//
//===----------------------------------------------------------------------===//
@@ -43,7 +20,7 @@
#include "llvm/Assembly/Writer.h"
-//#define DEBUG_PEEPHOLE_INSTS 1
+#define DEBUG_PEEPHOLE_INSTS 1
#ifdef DEBUG_PEEPHOLE_INSTS
#define PRINT_PEEPHOLE(ID, NUM, I) \
@@ -68,211 +45,12 @@
// cast instruction would cause the underlying bits to change.
//
static inline bool isReinterpretingCast(const CastInst *CI) {
- return !losslessCastableTypes(CI->getOperand(0)->getType(), CI->getType());
+ return!CI->getOperand(0)->getType()->isLosslesslyConvertableTo(CI->getType());
}
-// 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!
-}
-
-
-// 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!");
-
- // 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...
- }
-
- if (TheCast) // Is there a cast associated with this value?
- PtrCasts[*AI] = TheCast; // Yes, add it to the map...
- }
-
- // 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;
-}
-
-
-
-
-// DoElminatePointerArithmetic - Loop over each incoming pointer variable,
-// replacing indexing arithmetic with getelementptr calls.
-//
-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 & add 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.
-//
-// If these conditions hold, we convert the malloc to allocate an [RTy]
-// element. This should be extended in the future to handle arrays. TODO
-//
-static bool PeepholeMallocInst(BasicBlock *BB, BasicBlock::iterator &BI) {
- MallocInst *MI = cast<MallocInst>(*BI);
- if (!MI->isArrayAllocation()) return false; // No array allocation?
-
- ConstPoolUInt *Amt = dyn_cast<ConstPoolUInt>(MI->getArraySize());
- if (Amt == 0 || MI->getAllocatedType() != ArrayType::get(Type::SByteTy))
- return false;
-
- // Get the number of bytes allocated...
- unsigned Size = Amt->getValue();
- const Type *ResultTy = 0;
-
- // 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 (CastInst *CI = dyn_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 (isa<ArrayType>(DestTy)) {
- cerr << "Avoided malloc conversion because of type: " << DestTy
- << " TODO.\n";
- return false;
- }
- 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 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;
-
- // Now we check to see if we can convert the return value of malloc to the
- // specified pointer type. All this is moot if we can't.
- //
- ValueTypeCache ConvertedTypes;
- if (RetValConvertableToType(MI, PointerType::get(ResultTy), ConvertedTypes)) {
- // Yup, it's convertable, do the transformation now!
- PRINT_PEEPHOLE1("mall-refine:in ", MI);
-
- // Create a new malloc instruction, and insert it into the method...
- MallocInst *NewMI = new MallocInst(PointerType::get(ResultTy));
- NewMI->setName(MI->getName());
- MI->setName("");
- BI = BB->getInstList().insert(BI, NewMI)+1;
-
- // Create a new cast instruction to cast it to the old type...
- CastInst *NewCI = new CastInst(NewMI, MI->getType());
- BB->getInstList().insert(BI, NewCI);
-
- // Move all users of the old malloc instruction over to use the new cast...
- MI->replaceAllUsesWith(NewCI);
-
- ValueMapCache ValueMap;
- ConvertUsersType(NewCI, NewMI, ValueMap); // This will delete MI!
-
- BI = BB->begin(); // Rescan basic block. BI might be invalidated.
- PRINT_PEEPHOLE1("mall-refine:out", NewMI);
- return true;
- }
- return false;
-}
-
-
// Peephole optimize the following instructions:
// %t1 = cast ulong <const int> to {<...>} *
@@ -288,172 +66,41 @@
//
static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI,
Value *AddOp1, CastInst *AddOp2) {
- Value *OffsetVal = AddOp2->getOperand(0);
- Value *SrcPtr; // Of type pointer to struct...
- const StructType *StructTy;
+ const CompositeType *CompTy;
+ Value *OffsetVal = AddOp2->getOperand(0);
+ Value *SrcPtr; // Of type pointer to struct...
- if ((StructTy = getPointedToStruct(AddOp1->getType()))) {
+ 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...
- StructTy = getPointedToStruct(SrcPtr->getType());
+ CompTy = getPointedToComposite(SrcPtr->getType());
}
// Only proceed if we have detected all of our conditions successfully...
- if (!StructTy || !SrcPtr || !OffsetVal->getType()->isIntegral())
+ if (!CompTy || !SrcPtr || !OffsetVal->getType()->isIntegral())
return false;
- // See if the cast is of an integer expression that is either a constant,
- // or a value scaled by some amount with a possible offset.
- //
- analysis::ExprType Expr = analysis::ClassifyExpression(OffsetVal);
- unsigned Offset = 0, Scale = 1;
+ vector<Value*> Indices;
+ if (!ConvertableToGEP(SrcPtr->getType(), OffsetVal, Indices, &BI))
+ return false; // Not convertable... perhaps next time
- // The expression must either be a constant, or a scaled index to be useful
- if (!Expr.Offset && !Expr.Scale)
- return false;
-
- // Get the offset value if it exists...
- if (Expr.Offset) {
- if (ConstPoolSInt *CPSI = dyn_cast<ConstPoolSInt>(Expr.Offset))
- Offset = (unsigned)CPSI->getValue();
- else {
- ConstPoolUInt *CPUI = cast<ConstPoolUInt>(Expr.Offset);
- Offset = (unsigned)CPUI->getValue();
- }
- assert(Offset != 0 && "Expression analysis failure!");
- }
-
- // Get the scale value if it exists...
- if (Expr.Scale) {
- if (ConstPoolSInt *CPSI = dyn_cast<ConstPoolSInt>(Expr.Scale))
- Scale = (unsigned)CPSI->getValue();
- else {
- ConstPoolUInt *CPUI = cast<ConstPoolUInt>(Expr.Scale);
- Scale = (unsigned)CPUI->getValue();
- }
- assert(Scale != 1 && "Expression analysis failure!");
- }
-
- // Check to make sure the offset is not negative or really large, outside the
- // scope of this structure...
- //
- if (Offset >= TD.getTypeSize(StructTy))
- return false;
-
- 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
+ if (getPointedToComposite(AddOp1->getType())) { // case 1
PRINT_PEEPHOLE2("add-to-gep1:in", AddOp2, *BI);
} else {
PRINT_PEEPHOLE3("add-to-gep2:in", AddOp1, AddOp2, *BI);
}
- GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Offsets);
- //AddOp2->getName());
+ GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Indices,
+ AddOp2->getName());
BI = BB->getInstList().insert(BI, GEP)+1;
-
- Instruction *AddrSrc = GEP;
-
- if (const ArrayType *AT = dyn_cast<ArrayType>(ElTy)) {
- assert((Scale == 1 || Offset == ActualOffset) &&
- "Cannot handle scaled expression and unused offset in the same "
- "instruction until after GEP array works!");
- // Check to see if we have bottomed out INSIDE of an array reference..
- //
- if (Offset != ActualOffset) {
- // Insert a cast of the "rest" of the offset to the appropriate
- // pointer type.
- CastInst *OffInst =
- new CastInst(ConstPoolUInt::get(Type::ULongTy,
- Offset-ActualOffset),
- GEP->getType());
- BI = BB->getInstList().insert(BI, OffInst)+1;
-
- // Now insert an ADD to actually adjust the pointer...
- Instruction *AddInst =
- BinaryOperator::create(Instruction::Add, GEP, OffInst);
- BI = BB->getInstList().insert(BI, AddInst)+1;
-
- PRINT_PEEPHOLE2("add-to-gep:out1", OffInst, AddInst);
-
- AddrSrc = AddInst;
- } else if (Scale != 1) {
- // If the scale factor occurs, then this means that there is an index into
- // this element of the array. Check to make sure the scale factor is the
- // same as the size of the datatype that we are dealing with.
- //
- assert(Scale == TD.getTypeSize(AT->getElementType()) &&
- "Scaling by something other than the array element size!!");
-
- // TODO: In the future, we will not want to cast the index and scale to
- // pointer types first. We will want to create a GEP directly here.
-
- // Now we must actually perform the scaling operation to get an
- // appropriate value to add in... but the scale has to be done in the
- // appropriate destination pointer type, so cast the index value now.
- //
- // Cast the base index pointer
- CastInst *IdxValue = new CastInst(Expr.Var, GEP->getType());
- BI = BB->getInstList().insert(BI, IdxValue)+1;
-
- // Case the scale amount as well...
- CastInst *ScaleAmt =
- new CastInst(ConstPoolUInt::get(Type::ULongTy, Scale), GEP->getType());
- BI = BB->getInstList().insert(BI, ScaleAmt)+1;
-
- // Insert the multiply now. Make sure to make the constant the second arg
- Instruction *ScaledVal =
- BinaryOperator::create(Instruction::Mul, IdxValue, ScaleAmt);
- BI = BB->getInstList().insert(BI, ScaledVal)+1;
-
- // Now insert an ADD to actually adjust the pointer...
- Instruction *AddInst =
- BinaryOperator::create(Instruction::Add, GEP, ScaledVal);
- BI = BB->getInstList().insert(BI, AddInst)+1;
-
- PRINT_PEEPHOLE4("add-to-gep:out1", IdxValue, ScaleAmt, ScaledVal,
- AddInst);
- AddrSrc = AddInst;
- }
-
- // Insert a cast of the pointer to array of X to be a pointer to the
- // element of the array.
- //
- // Insert a cast of the "rest" of the offset to the appropriate
- // pointer type.
- CastInst *ACI = new CastInst(AddrSrc, AT->getElementType());
- BI = BB->getInstList().insert(BI, ACI)+1;
- AddrSrc = ACI;
-
- } else {
- assert(Offset == ActualOffset && "GEP to middle of non array!");
- assert(Scale == 1 && "Scale factor for expr that is not an array idx!");
- }
-
- Instruction *NCI = new CastInst(AddrSrc, AddOp1->getType());
+ 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;
@@ -502,14 +149,14 @@
// specific type of the operands to do it's job.
if (!isReinterpretingCast(CI)) {
ValueTypeCache ConvertedTypes;
- if (RetValConvertableToType(CI, Src->getType(), ConvertedTypes)) {
- PRINT_PEEPHOLE2("CAST-DEST-EXPR-CONV:in ", CI, Src);
+ if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) {
+ PRINT_PEEPHOLE2("CAST-DEST-EXPR-CONV:in ", Src, CI);
#ifdef DEBUG_PEEPHOLE_INSTS
cerr << "\nCONVERTING EXPR TYPE:\n";
#endif
ValueMapCache ValueMap;
- ConvertUsersType(CI, Src, ValueMap); // This will delete CI!
+ 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);
@@ -520,7 +167,7 @@
} else {
ConvertedTypes.clear();
if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) {
- PRINT_PEEPHOLE2("CAST-SRC-EXPR-CONV:in ", CI, Src);
+ PRINT_PEEPHOLE2("CAST-SRC-EXPR-CONV:in ", Src, CI);
#ifdef DEBUG_PEEPHOLE_INSTS
cerr << "\nCONVERTING SRC EXPR TYPE:\n";
@@ -552,7 +199,7 @@
// %t1 = cast <eltype> * %t1 to <ty> *
//
#if 1
- if (const StructType *STy = getPointedToStruct(Src->getType()))
+ 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
@@ -574,24 +221,34 @@
if (!HasAddUse) {
const Type *DestPointedTy = DestPTy->getValueType();
unsigned Depth = 1;
- const StructType *CurSTy = STy;
+ const CompositeType *CurCTy = CTy;
const Type *ElTy = 0;
- while (CurSTy) {
+
+ // Build the index vector, full of all zeros
+ vector<Value*> Indices;
+
+ while (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;
- // 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(ConstPoolUInt::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;
}
@@ -599,10 +256,6 @@
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());
@@ -622,12 +275,6 @@
#endif
#if 1
- } 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;
-
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
Value *Val = SI->getOperand(0);
Value *Pointer = SI->getPointerOperand();
@@ -642,9 +289,8 @@
// Append any indices that the store instruction has onto the end of the
// ones that the GEP is carrying...
//
- vector<ConstPoolVal*> Indices(GEP->getIndices());
- Indices.insert(Indices.end(), SI->getIndices().begin(),
- SI->getIndices().end());
+ vector<Value*> Indices(GEP->copyIndices());
+ Indices.insert(Indices.end(), SI->idx_begin(), SI->idx_end());
PRINT_PEEPHOLE2("gep-store:in", GEP, SI);
ReplaceInstWithInst(BB->getInstList(), BI,
@@ -665,8 +311,8 @@
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->getValueType()) &&
!SI->hasIndices()) { // No subscripts yet!
PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI);
@@ -697,9 +343,8 @@
// Append any indices that the load instruction has onto the end of the
// ones that the GEP is carrying...
//
- vector<ConstPoolVal*> Indices(GEP->getIndices());
- Indices.insert(Indices.end(), LI->getIndices().begin(),
- LI->getIndices().end());
+ vector<Value*> Indices(GEP->copyIndices());
+ Indices.insert(Indices.end(), LI->idx_begin(), LI->idx_end());
PRINT_PEEPHOLE2("gep-load:in", GEP, LI);
ReplaceInstWithInst(BB->getInstList(), BI,
@@ -729,7 +374,8 @@
const Type *ElTy = SrcTy ? SrcTy->getValueType() : 0;
// Make sure that nothing will be lost in the new cast...
- if (SrcTy && losslessCastableTypes(ElTy, LI->getType())) {
+ if (!LI->hasIndices() && SrcTy &&
+ ElTy->isLosslesslyConvertableTo(LI->getType())) {
PRINT_PEEPHOLE2("CL-LoadCast:in ", CI, LI);
string CName = CI->getName(); CI->setName("");
@@ -785,37 +431,143 @@
}
+
+
+// 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(Value *V, BasicBlock *BB,
+ BasicBlock::iterator InsertBefore) {
+ const PointerType *ThePtrType = dyn_cast<PointerType>(V->getType());
+ if (!ThePtrType) return false;
+
+ const Type *ElTy = ThePtrType->getValueType();
+ if (isa<MethodType>(ElTy) || isa<ArrayType>(ElTy)) return false;
+
+ unsigned ElementSize = TD.getTypeSize(ElTy);
+ 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()) {
+ 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! Don't mess around with it.
+ return false; // No changes made to program though...
+ }
+ break;
+ case Instruction::Add: { // Analyze pointer arithmetic...
+ Value *OtherOp = Inst->getOperand(Inst->getOperand(0) == V);
+ analysis::ExprType Expr = analysis::ClassifyExpression(OtherOp);
+
+ // This looks like array addressing iff:
+ // A. The constant of the index is larger than the size of the element
+ // type.
+ // B. The scale factor is >= the size of the type.
+ //
+ if (Expr.Offset && getConstantValue(Expr.Offset) >= (int)ElementSize) // A
+ InsertCast = true;
+
+ if (Expr.Scale && getConstantValue(Expr.Scale) >= (int)ElementSize) // B
+ InsertCast = true;
+
+ break;
+ }
+ default: break; // Not an interesting use...
+ }
+ }
+
+ if (!InsertCast) return false; // There is no reason to insert a cast!
+
+ // Calculate the destination pointer type
+ const PointerType *DestTy = PointerType::get(ArrayType::get(ElTy));
+
+ // Check to make sure that all uses of the value can be converted over to use
+ // the newly typed value.
+ //
+ ValueTypeCache ConvertedTypes;
+ if (!ValueConvertableToType(V, DestTy, ConvertedTypes)) {
+ cerr << "FAILED to convert types of values for " << V << "\n";
+ ConvertedTypes.clear();
+ ValueConvertableToType(V, DestTy, ConvertedTypes);
+ return false;
+ }
+ ConvertedTypes.clear();
+
+ // Insert a cast!
+ CastInst *TheCast =
+ new CastInst(ConstPoolVal::getNullConstant(V->getType()), DestTy,
+ V->getName());
+ BB->getInstList().insert(InsertBefore, TheCast);
+
+ cerr << "Inserting cast for " << V << endl;
+
+ // Convert users of the old value over to use the cast result...
+ ValueMapCache VMC;
+ ConvertValueToNewType(V, TheCast, VMC);
+
+ // The cast is the only thing that is allowed to reference the value...
+ TheCast->setOperand(0, V);
+
+ cerr << "Inserted ptr-array cast: " << TheCast;
+ return true; // Made a change!
+}
+
+
+// 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, or a pointer returned from a function call.
+//
+static bool DoInsertArrayCasts(Method *M) {
+ assert(!M->isExternal() && "Can't handle external methods!");
+
+ // Insert casts for all arguments to the function...
+ bool Changed = false;
+ BasicBlock *CurBB = M->front();
+
+ for (Method::ArgumentListType::iterator AI = M->getArgumentList().begin(),
+ AE = M->getArgumentList().end(); AI != AE; ++AI) {
+
+ Changed |= DoInsertArrayCast(*AI, CurBB, CurBB->begin());
+ }
+
+ // 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;
+}
+
+
+
+
// RaisePointerReferences::doit - Raise a method representation to a higher
// level.
//
bool RaisePointerReferences::doit(Method *M) {
if (M->isExternal()) return false;
- bool Changed = false;
#ifdef DEBUG_PEEPHOLE_INSTS
cerr << "\n\n\nStarting to work on Method '" << M->getName() << "'\n";
#endif
- while (DoRaisePass(M)) Changed = true;
-
-#if 0
- // 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;
-
- // Insert casts for all incoming pointer values. Keep track of those casts
- // and the identified incoming values in the PtrCasts map.
+ // Insert casts for all incoming pointer pointer values that are treated as
+ // arrays...
//
- Changed |= DoInsertArrayCasts(M, PtrCasts);
+ bool Changed = false, LocalChange;
+ do {
+ LocalChange = DoInsertArrayCasts(M);
- // Loop over each incoming pointer variable, replacing indexing arithmetic
- // with getelementptr calls.
- //
- Changed |= reduce_apply_bool(PtrCasts.begin(), PtrCasts.end(),
- ptr_fun(DoEliminatePointerArithmetic));
-#endif
+ // Iterate over the method, refining it, until it converges on a stable
+ // state
+ while (DoRaisePass(M)) LocalChange = true;
+ Changed |= LocalChange;
+
+ } while (LocalChange);
return Changed;
}