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llvm-6502/lib/Transforms/ExprTypeConvert.cpp
Chris Lattner 5f4a5289d4 Fix bug test/Regression/Transforms/LevelRaise/2002-03-21-MissedRaise3.ll 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1943 91177308-0d34-0410-b5e6-96231b3b80d8
2002-03-21 23:02:37 +00:00

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//===- ExprTypeConvert.cpp - Code to change an LLVM Expr Type ---------------=//
//
// This file implements the part of level raising that checks to see if it is
// possible to coerce an entire expression tree into a different type. If
// convertable, other routines from this file will do the conversion.
//
//===----------------------------------------------------------------------===//
#include "TransformInternals.h"
#include "llvm/Method.h"
#include "llvm/iOther.h"
#include "llvm/iPHINode.h"
#include "llvm/iMemory.h"
#include "llvm/ConstantVals.h"
#include "llvm/Transforms/Scalar/ConstantHandling.h"
#include "llvm/Transforms/Scalar/DCE.h"
#include "llvm/Analysis/Expressions.h"
#include "Support/STLExtras.h"
#include <map>
#include <algorithm>
#include <iostream>
using std::cerr;
#include "llvm/Assembly/Writer.h"
//#define DEBUG_EXPR_CONVERT 1
static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
ValueTypeCache &ConvertedTypes);
static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
ValueMapCache &VMC);
// AllIndicesZero - Return true if all of the indices of the specified memory
// access instruction are zero, indicating an effectively nil offset to the
// pointer value.
//
static bool AllIndicesZero(const MemAccessInst *MAI) {
for (User::const_op_iterator S = MAI->idx_begin(), E = MAI->idx_end();
S != E; ++S)
if (!isa<Constant>(*S) || !cast<Constant>(*S)->isNullValue())
return false;
return true;
}
// 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. TODO: This comment is out of date WRT arrays
//
static bool MallocConvertableToType(MallocInst *MI, const Type *Ty,
ValueTypeCache &CTMap) {
if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
// Deal with the type to allocate, not the pointer type...
Ty = cast<PointerType>(Ty)->getElementType();
if (!Ty->isSized()) return false; // Can only alloc something with a size
// Analyze the number of bytes allocated...
analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
// Get information about the base datatype being allocated, before & after
unsigned ReqTypeSize = TD.getTypeSize(Ty);
unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
// Must have a scale or offset to analyze it...
if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
// Get the offset and scale of the allocation...
int OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
if (ScaleVal < 0 || OffsetVal < 0) {
cerr << "malloc of a negative number???\n";
return false;
}
// The old type might not be of unit size, take old size into consideration
// here...
unsigned Offset = (unsigned)OffsetVal * OldTypeSize;
unsigned Scale = (unsigned)ScaleVal * OldTypeSize;
// In order to be successful, both the scale and the offset must be a multiple
// of the requested data type's size.
//
if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
Scale/ReqTypeSize*ReqTypeSize != Scale)
return false; // Nope.
return true;
}
static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
const std::string &Name,
ValueMapCache &VMC){
BasicBlock *BB = MI->getParent();
BasicBlock::iterator It = BB->end();
// Analyze the number of bytes allocated...
analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
const PointerType *AllocTy = cast<PointerType>(Ty);
const Type *ElType = AllocTy->getElementType();
unsigned DataSize = TD.getTypeSize(ElType);
unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
// Get the offset and scale coefficients that we are allocating...
int OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
// The old type might not be of unit size, take old size into consideration
// here...
unsigned Offset = (unsigned)OffsetVal * OldTypeSize / DataSize;
unsigned Scale = (unsigned)ScaleVal * OldTypeSize / DataSize;
// Locate the malloc instruction, because we may be inserting instructions
It = find(BB->getInstList().begin(), BB->getInstList().end(), MI);
// If we have a scale, apply it first...
if (Expr.Var) {
// Expr.Var is not neccesarily unsigned right now, insert a cast now.
if (Expr.Var->getType() != Type::UIntTy) {
Instruction *CI = new CastInst(Expr.Var, Type::UIntTy);
if (Expr.Var->hasName()) CI->setName(Expr.Var->getName()+"-uint");
It = BB->getInstList().insert(It, CI)+1;
Expr.Var = CI;
}
if (Scale != 1) {
Instruction *ScI =
BinaryOperator::create(Instruction::Mul, Expr.Var,
ConstantUInt::get(Type::UIntTy, Scale));
if (Expr.Var->hasName()) ScI->setName(Expr.Var->getName()+"-scl");
It = BB->getInstList().insert(It, ScI)+1;
Expr.Var = ScI;
}
} else {
// If we are not scaling anything, just make the offset be the "var"...
Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
Offset = 0; Scale = 1;
}
// If we have an offset now, add it in...
if (Offset != 0) {
assert(Expr.Var && "Var must be nonnull by now!");
Instruction *AddI =
BinaryOperator::create(Instruction::Add, Expr.Var,
ConstantUInt::get(Type::UIntTy, Offset));
if (Expr.Var->hasName()) AddI->setName(Expr.Var->getName()+"-off");
It = BB->getInstList().insert(It, AddI)+1;
Expr.Var = AddI;
}
Instruction *NewI = new MallocInst(AllocTy, Expr.Var, Name);
assert(AllocTy == Ty);
return NewI;
}
// ExpressionConvertableToType - Return true if it is possible
bool ExpressionConvertableToType(Value *V, const Type *Ty,
ValueTypeCache &CTMap) {
if (V->getType() == Ty) return true; // Expression already correct type!
// Expression type must be holdable in a register.
if (!Ty->isFirstClassType())
return false;
ValueTypeCache::iterator CTMI = CTMap.find(V);
if (CTMI != CTMap.end()) return CTMI->second == Ty;
CTMap[V] = 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). We just ask the constant propogator to see if
// it can convert the value...
//
if (Constant *CPV = dyn_cast<Constant>(V))
if (ConstantFoldCastInstruction(CPV, Ty))
return true; // Don't worry about deallocating, it's a constant.
return false; // Otherwise, we can't convert!
}
switch (I->getOpcode()) {
case Instruction::Cast:
// We can convert the expr if the cast destination type is losslessly
// convertable to the requested type.
if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
#if 1
// We also do not allow conversion of a cast that casts from a ptr to array
// of X to a *X. For example: cast [4 x %List *] * %val to %List * *
//
if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
if (AT->getElementType() == DPT->getElementType())
return false;
#endif
break;
case Instruction::Add:
case Instruction::Sub:
if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
!ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
return false;
break;
case Instruction::Shr:
if (Ty->isSigned() != V->getType()->isSigned()) return false;
// FALL THROUGH
case Instruction::Shl:
if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
return false;
break;
case Instruction::Load: {
LoadInst *LI = cast<LoadInst>(I);
if (LI->hasIndices() && !AllIndicesZero(LI)) {
// We can't convert a load expression if it has indices... unless they are
// all zero.
return false;
}
if (!ExpressionConvertableToType(LI->getPointerOperand(),
PointerType::get(Ty), CTMap))
return false;
break;
}
case Instruction::PHINode: {
PHINode *PN = cast<PHINode>(I);
for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
return false;
break;
}
case Instruction::Malloc:
if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
return false;
break;
#if 1
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; // GEP must always return a pointer...
const Type *PVTy = PTy->getElementType();
// 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...
//
std::vector<Value*> Indices = GEP->copyIndices();
const Type *BaseType = GEP->getPointerOperand()->getType();
const Type *ElTy = 0;
while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
cast<ConstantUInt>(Indices.back())->getValue() == 0) {
Indices.pop_back();
ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
if (ElTy == PVTy)
break; // Found a match!!
ElTy = 0;
}
if (ElTy) break; // Found a number of zeros we can strip off!
// Otherwise, we can convert a GEP from one form to the other iff the
// current gep is of the form 'getelementptr sbyte*, unsigned N
// and we could convert this to an appropriate GEP for the new type.
//
if (GEP->getNumOperands() == 2 &&
GEP->getOperand(1)->getType() == Type::UIntTy &&
GEP->getType() == PointerType::get(Type::SByteTy)) {
// Do not Check to see if our incoming pointer can be converted
// to be a ptr to an array of the right type... because in more cases than
// not, it is simply not analyzable because of pointer/array
// discrepencies. To fix this, we will insert a cast before the GEP.
//
// Check to see if 'N' is an expression that can be converted to
// the appropriate size... if so, allow it.
//
std::vector<Value*> Indices;
const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
if (ElTy == PVTy) {
if (!ExpressionConvertableToType(I->getOperand(0),
PointerType::get(ElTy), CTMap))
return false; // Can't continue, ExConToTy might have polluted set!
break;
}
}
// Otherwise, it could be that we have something like this:
// getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
// and want to convert it into something like this:
// getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
//
if (GEP->getNumOperands() == 2 &&
GEP->getOperand(1)->getType() == Type::UIntTy &&
TD.getTypeSize(PTy->getElementType()) ==
TD.getTypeSize(GEP->getType()->getElementType())) {
const PointerType *NewSrcTy = PointerType::get(PVTy);
if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
return false;
break;
}
return false; // No match, maybe next time.
}
#endif
default:
return false;
}
// Expressions are only convertable if all of the users of the expression can
// have this value converted. This makes use of the map to avoid infinite
// recursion.
//
for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
if (!OperandConvertableToType(*It, I, Ty, CTMap))
return false;
return true;
}
Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
if (V->getType() == Ty) return V; // Already where we need to be?
ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
if (VMCI != VMC.ExprMap.end()) {
assert(VMCI->second->getType() == Ty);
if (Instruction *I = dyn_cast<Instruction>(V))
ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
return VMCI->second;
}
#ifdef DEBUG_EXPR_CONVERT
cerr << "CETT: " << (void*)V << " " << V;
#endif
Instruction *I = dyn_cast<Instruction>(V);
if (I == 0)
if (Constant *CPV = cast<Constant>(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 = ConstantFoldCastInstruction(CPV, Ty);
assert(Result && "ConstantFoldCastInstruction Failed!!!");
assert(Result->getType() == Ty && "Const prop of cast failed!");
// Add the instruction to the expression map
VMC.ExprMap[V] = Result;
return Result;
}
BasicBlock *BB = I->getParent();
BasicBlock::InstListType &BIL = BB->getInstList();
std::string Name = I->getName(); if (!Name.empty()) I->setName("");
Instruction *Res; // Result of conversion
ValueHandle IHandle(VMC, I); // Prevent I from being removed!
Constant *Dummy = Constant::getNullConstant(Ty);
switch (I->getOpcode()) {
case Instruction::Cast:
Res = new CastInst(I->getOperand(0), Ty, Name);
break;
case Instruction::Add:
case Instruction::Sub:
Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
Dummy, Dummy, Name);
VMC.ExprMap[I] = Res; // Add node to expression eagerly
Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
break;
case Instruction::Shl:
case Instruction::Shr:
Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
I->getOperand(1), Name);
VMC.ExprMap[I] = Res;
Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
break;
case Instruction::Load: {
LoadInst *LI = cast<LoadInst>(I);
assert(!LI->hasIndices() || AllIndicesZero(LI));
Res = new LoadInst(Constant::getNullConstant(PointerType::get(Ty)), Name);
VMC.ExprMap[I] = Res;
Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
PointerType::get(Ty), VMC));
assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
assert(Ty == Res->getType());
assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
break;
}
case Instruction::PHINode: {
PHINode *OldPN = cast<PHINode>(I);
PHINode *NewPN = new PHINode(Ty, Name);
VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
while (OldPN->getNumOperands()) {
BasicBlock *BB = OldPN->getIncomingBlock(0);
Value *OldVal = OldPN->getIncomingValue(0);
ValueHandle OldValHandle(VMC, OldVal);
OldPN->removeIncomingValue(BB);
Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
NewPN->addIncoming(V, BB);
}
Res = NewPN;
break;
}
case Instruction::Malloc: {
Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
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...
//
std::vector<Value*> Indices = GEP->copyIndices();
const Type *BaseType = GEP->getPointerOperand()->getType();
const Type *PVTy = cast<PointerType>(Ty)->getElementType();
Res = 0;
while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
cast<ConstantUInt>(Indices.back())->getValue() == 0) {
Indices.pop_back();
if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
if (Indices.size() == 0) {
Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
} else {
Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
}
break;
}
}
if (Res == 0 && GEP->getNumOperands() == 2 &&
GEP->getOperand(1)->getType() == Type::UIntTy &&
GEP->getType() == PointerType::get(Type::SByteTy)) {
// Otherwise, we can convert a GEP from one form to the other iff the
// current gep is of the form 'getelementptr [sbyte]*, unsigned N
// and we could convert this to an appropriate GEP for the new type.
//
const PointerType *NewSrcTy = PointerType::get(PVTy);
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
// Check to see if 'N' is an expression that can be converted to
// the appropriate size... if so, allow it.
//
std::vector<Value*> Indices;
const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
Indices, &It);
if (ElTy) {
assert(ElTy == PVTy && "Internal error, setup wrong!");
Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
Indices, Name);
VMC.ExprMap[I] = Res;
Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
NewSrcTy, VMC));
}
}
// Otherwise, it could be that we have something like this:
// getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
// and want to convert it into something like this:
// getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
//
if (Res == 0) {
const PointerType *NewSrcTy = PointerType::get(PVTy);
Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
GEP->copyIndices(), Name);
VMC.ExprMap[I] = Res;
Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
NewSrcTy, VMC));
}
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;
}
assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
assert(It != BIL.end() && "Instruction not in own basic block??");
BIL.insert(It, Res);
// Add the instruction to the expression map
VMC.ExprMap[I] = Res;
// Expressions are only convertable if all of the users of the expression can
// have this value converted. This makes use of the map to avoid infinite
// recursion.
//
unsigned NumUses = I->use_size();
for (unsigned It = 0; It < NumUses; ) {
unsigned OldSize = NumUses;
ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
NumUses = I->use_size();
if (NumUses == OldSize) ++It;
}
#ifdef DEBUG_EXPR_CONVERT
cerr << "ExpIn: " << (void*)I << " " << I
<< "ExpOut: " << (void*)Res << " " << Res;
#endif
if (I->use_empty()) {
#ifdef DEBUG_EXPR_CONVERT
cerr << "EXPR DELETING: " << (void*)I << " " << I;
#endif
BIL.remove(I);
VMC.OperandsMapped.erase(I);
VMC.ExprMap.erase(I);
delete I;
}
return Res;
}
// ValueConvertableToType - Return true if it is possible
bool ValueConvertableToType(Value *V, const Type *Ty,
ValueTypeCache &ConvertedTypes) {
ValueTypeCache::iterator I = ConvertedTypes.find(V);
if (I != ConvertedTypes.end()) return I->second == Ty;
ConvertedTypes[V] = Ty;
// It is safe to convert the specified value to the specified type IFF all of
// the uses of the value can be converted to accept the new typed value.
//
if (V->getType() != Ty) {
for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
return false;
}
return true;
}
// OperandConvertableToType - Return true if it is possible to convert operand
// V of User (instruction) U to the specified type. This is true iff it is
// possible to change the specified instruction to accept this. CTMap is a map
// of converted types, so that circular definitions will see the future type of
// the expression, not the static current type.
//
static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
ValueTypeCache &CTMap) {
// if (V->getType() == Ty) return true; // Operand already the right type?
// Expression type must be holdable in a register.
if (!Ty->isFirstClassType())
return false;
Instruction *I = dyn_cast<Instruction>(U);
if (I == 0) return false; // We can't convert!
switch (I->getOpcode()) {
case Instruction::Cast:
assert(I->getOperand(0) == V);
// We can convert the expr if the cast destination type is losslessly
// convertable to the requested type.
// Also, do not change a cast that is a noop cast. For all intents and
// purposes it should be eliminated.
if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
I->getType() == I->getOperand(0)->getType())
return false;
#if 1
// We also do not allow conversion of a cast that casts from a ptr to array
// of X to a *X. For example: cast [4 x %List *] * %val to %List * *
//
if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
if (AT->getElementType() == DPT->getElementType())
return false;
#endif
return true;
case Instruction::Add:
if (isa<PointerType>(Ty)) {
Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
std::vector<Value*> Indices;
if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
const Type *RetTy = PointerType::get(ETy);
// Only successful if we can convert this type to the required type
if (ValueConvertableToType(I, RetTy, CTMap)) {
CTMap[I] = RetTy;
return true;
}
// We have to return failure here because ValueConvertableToType could
// have polluted our map
return false;
}
}
// FALLTHROUGH
case Instruction::Sub: {
Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
return ValueConvertableToType(I, Ty, CTMap) &&
ExpressionConvertableToType(OtherOp, Ty, CTMap);
}
case Instruction::SetEQ:
case Instruction::SetNE: {
Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
return ExpressionConvertableToType(OtherOp, Ty, CTMap);
}
case Instruction::Shr:
if (Ty->isSigned() != V->getType()->isSigned()) return false;
// FALL THROUGH
case Instruction::Shl:
assert(I->getOperand(0) == V);
return ValueConvertableToType(I, Ty, CTMap);
case Instruction::Free:
assert(I->getOperand(0) == V);
return isa<PointerType>(Ty); // Free can free any pointer type!
case Instruction::Load:
// Cannot convert the types of any subscripts...
if (I->getOperand(0) != V) return false;
if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
LoadInst *LI = cast<LoadInst>(I);
if (LI->hasIndices() && !AllIndicesZero(LI))
return false;
const Type *LoadedTy = PT->getElementType();
// They could be loading the first element of a composite type...
if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
unsigned Offset = 0; // No offset, get first leaf.
std::vector<Value*> Indices; // Discarded...
LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
assert(Offset == 0 && "Offset changed from zero???");
}
if (!LoadedTy->isFirstClassType())
return false;
if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
return false;
return ValueConvertableToType(LI, LoadedTy, CTMap);
}
return false;
case Instruction::Store: {
StoreInst *SI = cast<StoreInst>(I);
if (SI->hasIndices()) return false;
if (V == I->getOperand(0)) {
ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
// If so, check to see if it's Ty*, or, more importantly, if it is a
// pointer to a structure where the first element is a Ty... this code
// is neccesary because we might be trying to change the source and
// destination type of the store (they might be related) and the dest
// pointer type might be a pointer to structure. Below we allow pointer
// to structures where the 0th element is compatible with the value,
// now we have to support the symmetrical part of this.
//
const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
// Already a pointer to what we want? Trivially accept...
if (ElTy == Ty) return true;
// Tricky case now, if the destination is a pointer to structure,
// obviously the source is not allowed to be a structure (cannot copy
// a whole structure at a time), so the level raiser must be trying to
// store into the first field. Check for this and allow it now:
//
if (StructType *SElTy = dyn_cast<StructType>(ElTy)) {
unsigned Offset = 0;
std::vector<Value*> Indices;
ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
assert(Offset == 0 && "Offset changed!");
if (ElTy == 0) // Element at offset zero in struct doesn't exist!
return false; // Can only happen for {}*
if (ElTy == Ty) // Looks like the 0th element of structure is
return true; // compatible! Accept now!
// Otherwise we know that we can't work, so just stop trying now.
return false;
}
}
// Can convert the store if we can convert the pointer operand to match
// the new value type...
return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
CTMap);
} else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
const Type *ElTy = PT->getElementType();
assert(V == I->getOperand(1));
if (isa<StructType>(ElTy)) {
// We can change the destination pointer if we can store our first
// argument into the first element of the structure...
//
unsigned Offset = 0;
std::vector<Value*> Indices;
ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
assert(Offset == 0 && "Offset changed!");
if (ElTy == 0) // Element at offset zero in struct doesn't exist!
return false; // Can only happen for {}*
}
// Must move the same amount of data...
if (TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
return false;
// Can convert store if the incoming value is convertable...
return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
}
return false;
}
case Instruction::GetElementPtr:
if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
// If we have a two operand form of getelementptr, this is really little
// more than a simple addition. As with addition, check to see if the
// getelementptr instruction can be changed to index into the new type.
//
if (I->getNumOperands() == 2) {
const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
unsigned DataSize = TD.getTypeSize(OldElTy);
Value *Index = I->getOperand(1);
Instruction *TempScale = 0;
// If the old data element is not unit sized, we have to create a scale
// instruction so that ConvertableToGEP will know the REAL amount we are
// indexing by. Note that this is never inserted into the instruction
// stream, so we have to delete it when we're done.
//
if (DataSize != 1) {
TempScale = BinaryOperator::create(Instruction::Mul, Index,
ConstantUInt::get(Type::UIntTy,
DataSize));
Index = TempScale;
}
// Check to see if the second argument is an expression that can
// be converted to the appropriate size... if so, allow it.
//
std::vector<Value*> Indices;
const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
delete TempScale; // Free our temporary multiply if we made it
if (ElTy == 0) return false; // Cannot make conversion...
return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
}
return false;
case Instruction::PHINode: {
PHINode *PN = cast<PHINode>(I);
for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
return false;
return ValueConvertableToType(PN, Ty, CTMap);
}
case Instruction::Call: {
User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
assert (OI != I->op_end() && "Not using value!");
unsigned OpNum = OI - I->op_begin();
// Are we trying to change the method pointer value to a new type?
if (OpNum == 0) {
PointerType *PTy = dyn_cast<PointerType>(Ty);
if (PTy == 0) return false; // Can't convert to a non-pointer type...
MethodType *MTy = dyn_cast<MethodType>(PTy->getElementType());
if (MTy == 0) return false; // Can't convert to a non ptr to method...
// Perform sanity checks to make sure that new method type has the
// correct number of arguments...
//
unsigned NumArgs = I->getNumOperands()-1; // Don't include method ptr
// Cannot convert to a type that requires more fixed arguments than
// the call provides...
//
if (NumArgs < MTy->getParamTypes().size()) return false;
// Unless this is a vararg method type, we cannot provide more arguments
// than are desired...
//
if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
return false;
// Okay, at this point, we know that the call and the method type match
// number of arguments. Now we see if we can convert the arguments
// themselves. Note that we do not require operands to be convertable,
// we can insert casts if they are convertible but not compatible. The
// reason for this is that we prefer to have resolved methods but casted
// arguments if possible.
//
const MethodType::ParamTypes &PTs = MTy->getParamTypes();
for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
return false; // Operands must have compatible types!
// Okay, at this point, we know that all of the arguments can be
// converted. We succeed if we can change the return type if
// neccesary...
//
return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
}
const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
const MethodType *MTy = cast<MethodType>(MPtr->getElementType());
if (!MTy->isVarArg()) return false;
if ((OpNum-1) < MTy->getParamTypes().size())
return false; // It's not in the varargs section...
// If we get this far, we know the value is in the varargs section of the
// method! We can convert if we don't reinterpret the value...
//
return Ty->isLosslesslyConvertableTo(V->getType());
}
}
return false;
}
void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
ValueHandle VH(VMC, V);
unsigned NumUses = V->use_size();
for (unsigned It = 0; It < NumUses; ) {
unsigned OldSize = NumUses;
ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
NumUses = V->use_size();
if (NumUses == OldSize) ++It;
}
}
static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
ValueMapCache &VMC) {
if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
if (VMC.OperandsMapped.count(U)) return;
VMC.OperandsMapped.insert(U);
ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
if (VMCI != VMC.ExprMap.end())
return;
Instruction *I = cast<Instruction>(U); // Only Instructions convertable
BasicBlock *BB = I->getParent();
BasicBlock::InstListType &BIL = BB->getInstList();
std::string Name = I->getName(); if (!Name.empty()) I->setName("");
Instruction *Res; // Result of conversion
//cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
// Prevent I from being removed...
ValueHandle IHandle(VMC, I);
const Type *NewTy = NewVal->getType();
Constant *Dummy = (NewTy != Type::VoidTy) ?
Constant::getNullConstant(NewTy) : 0;
switch (I->getOpcode()) {
case Instruction::Cast:
assert(I->getOperand(0) == OldVal);
Res = new CastInst(NewVal, I->getType(), Name);
break;
case Instruction::Add:
if (isa<PointerType>(NewTy)) {
Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
std::vector<Value*> Indices;
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
// If successful, convert the add to a GEP
//const Type *RetTy = PointerType::get(ETy);
// First operand is actually the given pointer...
Res = new GetElementPtrInst(NewVal, Indices, Name);
assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
"ConvertableToGEP broken!");
break;
}
}
// FALLTHROUGH
case Instruction::Sub:
case Instruction::SetEQ:
case Instruction::SetNE: {
Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
Dummy, Dummy, Name);
VMC.ExprMap[I] = Res; // Add node to expression eagerly
unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
Value *OtherOp = I->getOperand(OtherIdx);
Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
Res->setOperand(OtherIdx, NewOther);
Res->setOperand(!OtherIdx, NewVal);
break;
}
case Instruction::Shl:
case Instruction::Shr:
assert(I->getOperand(0) == OldVal);
Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
I->getOperand(1), Name);
break;
case Instruction::Free: // Free can free any pointer type!
assert(I->getOperand(0) == OldVal);
Res = new FreeInst(NewVal);
break;
case Instruction::Load: {
assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
const Type *LoadedTy =
cast<PointerType>(NewVal->getType())->getElementType();
std::vector<Value*> Indices;
Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
unsigned Offset = 0; // No offset, get first leaf.
LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
}
assert(LoadedTy->isFirstClassType());
Res = new LoadInst(NewVal, Indices, Name);
assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
break;
}
case Instruction::Store: {
if (I->getOperand(0) == OldVal) { // Replace the source value
const PointerType *NewPT = PointerType::get(NewTy);
Res = new StoreInst(NewVal, Constant::getNullConstant(NewPT));
VMC.ExprMap[I] = Res;
Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC));
} else { // Replace the source pointer
const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
std::vector<Value*> Indices;
if (isa<StructType>(ValTy)) {
unsigned Offset = 0;
Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
ValTy = getStructOffsetType(ValTy, Offset, Indices, false);
assert(Offset == 0 && ValTy);
}
Res = new StoreInst(Constant::getNullConstant(ValTy), NewVal, Indices);
VMC.ExprMap[I] = Res;
Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
}
break;
}
case Instruction::GetElementPtr: {
// Convert a one index getelementptr into just about anything that is
// desired.
//
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
unsigned DataSize = TD.getTypeSize(OldElTy);
Value *Index = I->getOperand(1);
if (DataSize != 1) {
// Insert a multiply of the old element type is not a unit size...
Index = BinaryOperator::create(Instruction::Mul, Index,
ConstantUInt::get(Type::UIntTy, DataSize));
It = BIL.insert(It, cast<Instruction>(Index))+1;
}
// Perform the conversion now...
//
std::vector<Value*> Indices;
const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
assert(ElTy != 0 && "GEP Conversion Failure!");
Res = new GetElementPtrInst(NewVal, Indices, Name);
assert(Res->getType() == PointerType::get(ElTy) &&
"ConvertableToGet failed!");
}
#if 0
if (I->getType() == PointerType::get(Type::SByteTy)) {
// Convert a getelementptr sbyte * %reg111, uint 16 freely back to
// anything that is a pointer type...
//
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
// Check to see if the second argument is an expression that can
// be converted to the appropriate size... if so, allow it.
//
std::vector<Value*> Indices;
const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
Indices, &It);
assert(ElTy != 0 && "GEP Conversion Failure!");
Res = new GetElementPtrInst(NewVal, Indices, Name);
} else {
// Convert a getelementptr ulong * %reg123, uint %N
// to getelementptr long * %reg123, uint %N
// ... where the type must simply stay the same size...
//
Res = new GetElementPtrInst(NewVal,
cast<GetElementPtrInst>(I)->copyIndices(),
Name);
}
#endif
break;
case Instruction::PHINode: {
PHINode *OldPN = cast<PHINode>(I);
PHINode *NewPN = new PHINode(NewTy, Name);
VMC.ExprMap[I] = NewPN;
while (OldPN->getNumOperands()) {
BasicBlock *BB = OldPN->getIncomingBlock(0);
Value *OldVal = OldPN->getIncomingValue(0);
OldPN->removeIncomingValue(BB);
Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
NewPN->addIncoming(V, BB);
}
Res = NewPN;
break;
}
case Instruction::Call: {
Value *Meth = I->getOperand(0);
std::vector<Value*> Params(I->op_begin()+1, I->op_end());
if (Meth == OldVal) { // Changing the method pointer?
PointerType *NewPTy = cast<PointerType>(NewVal->getType());
MethodType *NewTy = cast<MethodType>(NewPTy->getElementType());
const MethodType::ParamTypes &PTs = NewTy->getParamTypes();
// Get an iterator to the call instruction so that we can insert casts for
// operands if needbe. Note that we do not require operands to be
// convertable, we can insert casts if they are convertible but not
// compatible. The reason for this is that we prefer to have resolved
// methods but casted arguments if possible.
//
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
// Convert over all of the call operands to their new types... but only
// convert over the part that is not in the vararg section of the call.
//
for (unsigned i = 0; i < PTs.size(); ++i)
if (Params[i]->getType() != PTs[i]) {
// Create a cast to convert it to the right type, we know that this
// is a lossless cast...
//
Params[i] = new CastInst(Params[i], PTs[i], "call.resolve.cast");
It = BIL.insert(It, cast<Instruction>(Params[i]))+1;
}
Meth = NewVal; // Update call destination to new value
} else { // Changing an argument, must be in vararg area
std::vector<Value*>::iterator OI =
find(Params.begin(), Params.end(), OldVal);
assert (OI != Params.end() && "Not using value!");
*OI = NewVal;
}
Res = new CallInst(Meth, Params, Name);
break;
}
default:
assert(0 && "Expression convertable, but don't know how to convert?");
return;
}
// If the instruction was newly created, insert it into the instruction
// stream.
//
BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
assert(It != BIL.end() && "Instruction not in own basic block??");
BIL.insert(It, Res); // Keep It pointing to old instruction
#ifdef DEBUG_EXPR_CONVERT
cerr << "COT CREATED: " << (void*)Res << " " << Res;
cerr << "In: " << (void*)I << " " << I << "Out: " << (void*)Res << " " << Res;
#endif
// Add the instruction to the expression map
VMC.ExprMap[I] = Res;
if (I->getType() != Res->getType())
ConvertValueToNewType(I, Res, VMC);
else {
for (unsigned It = 0; It < I->use_size(); ) {
User *Use = *(I->use_begin()+It);
if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
++It;
else
Use->replaceUsesOfWith(I, Res);
}
if (I->use_empty()) {
// Now we just need to remove the old instruction so we don't get infinite
// loops. Note that we cannot use DCE because DCE won't remove a store
// instruction, for example.
//
#ifdef DEBUG_EXPR_CONVERT
cerr << "DELETING: " << (void*)I << " " << I;
#endif
BIL.remove(I);
VMC.OperandsMapped.erase(I);
VMC.ExprMap.erase(I);
delete I;
} else {
for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
UI != UE; ++UI)
assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
}
}
}
ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
: Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
#ifdef DEBUG_EXPR_CONVERT
//cerr << "VH AQUIRING: " << (void*)V << " " << V;
#endif
Operands.push_back(Use(V, this));
}
static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
if (!I || !I->use_empty()) return;
assert(I->getParent() && "Inst not in basic block!");
#ifdef DEBUG_EXPR_CONVERT
//cerr << "VH DELETING: " << (void*)I << " " << I;
#endif
for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
OI != OE; ++OI)
if (Instruction *U = dyn_cast<Instruction>(*OI)) {
*OI = 0;
RecursiveDelete(Cache, U);
}
I->getParent()->getInstList().remove(I);
Cache.OperandsMapped.erase(I);
Cache.ExprMap.erase(I);
delete I;
}
ValueHandle::~ValueHandle() {
if (Operands[0]->use_size() == 1) {
Value *V = Operands[0];
Operands[0] = 0; // Drop use!
// Now we just need to remove the old instruction so we don't get infinite
// loops. Note that we cannot use DCE because DCE won't remove a store
// instruction, for example.
//
RecursiveDelete(Cache, dyn_cast<Instruction>(V));
} else {
#ifdef DEBUG_EXPR_CONVERT
//cerr << "VH RELEASING: " << (void*)Operands[0].get() << " " << Operands[0]->use_size() << " " << Operands[0];
#endif
}
}
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