ConvertibleToGEP always returns 0, remove some old crufty code which

is actually dead because of this!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22515 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2005-07-26 16:38:28 +00:00
parent d6bbac500b
commit 600d73b548
4 changed files with 0 additions and 369 deletions

View File

@ -96,143 +96,6 @@ static inline bool isReinterpretingCast(const CastInst *CI) {
return!CI->getOperand(0)->getType()->isLosslesslyConvertibleTo(CI->getType());
}
// Peephole optimize the following instructions:
// %t1 = cast ? to x *
// %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand
//
// Into: %t3 = getelementptr {<...>} * %SP, <element indices>
// %t2 = cast <eltype> * %t3 to {<...>}*
//
static bool HandleCastToPointer(BasicBlock::iterator BI,
const PointerType *DestPTy,
const TargetData &TD) {
CastInst &CI = cast<CastInst>(*BI);
if (CI.use_empty()) return false;
// Scan all of the uses, looking for any uses that are not add or sub
// instructions. If we have non-adds, do not make this transformation.
//
bool HasSubUse = false; // Keep track of any subtracts...
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 &&
BO->getOpcode() != Instruction::Sub) ||
// Avoid add sbyte* %X, %X cases...
BO->getOperand(0) == BO->getOperand(1))
return false;
else
HasSubUse |= BO->getOpcode() == Instruction::Sub;
} else {
return false;
}
std::vector<Value*> Indices;
Value *Src = CI.getOperand(0);
const Type *Result = ConvertibleToGEP(DestPTy, Src, Indices, TD, &BI);
if (Result == 0) return false; // Not convertible...
// Cannot handle subtracts if there is more than one index required...
if (HasSubUse && Indices.size() != 1) return false;
PRINT_PEEPHOLE2("cast-add-to-gep:in", *Src, CI);
// 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->getOpcode() == Instruction::Sub) &&
"Use is not a valid add instruction!");
// 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 the instruction is actually a subtract, we are guaranteed to only have
// one index (from code above), so we just need to negate the pointer index
// long value.
if (I->getOpcode() == Instruction::Sub) {
Instruction *Neg = BinaryOperator::createNeg(GEP->getOperand(1),
GEP->getOperand(1)->getName()+".neg", I);
GEP->setOperand(1, Neg);
}
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...
I->getParent()->getInstList().insert(I, GEP);
PRINT_PEEPHOLE1("cast-add-to-gep:o", *GEP);
GEP = new CastInst(GEP, I->getType());
// Replace the old add instruction with the shiny new GEP inst
ReplaceInstWithInst(I, GEP);
}
PRINT_PEEPHOLE1("cast-add-to-gep:o", *GEP);
}
return true;
}
// 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 {<...>}*
//
static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI,
Value *AddOp1, CastInst *AddOp2,
const TargetData &TD) {
const CompositeType *CompTy;
Value *OffsetVal = AddOp2->getOperand(0);
Value *SrcPtr = 0; // 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());
}
// Only proceed if we have detected all of our conditions successfully...
if (!CompTy || !SrcPtr || !OffsetVal->getType()->isInteger())
return false;
std::vector<Value*> Indices;
if (!ConvertibleToGEP(SrcPtr->getType(), OffsetVal, Indices, TD, &BI))
return false; // Not convertible... perhaps next time
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, Indices,
AddOp2->getName(), BI);
Instruction *NCI = new CastInst(GEP, AddOp1->getType());
ReplaceInstWithInst(BB->getInstList(), BI, NCI);
PRINT_PEEPHOLE2("add-to-gep:out", *GEP, *NCI);
return true;
}
bool RPR::PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
Instruction *I = BI;
const TargetData &TD = getAnalysis<TargetData>();
@ -321,18 +184,6 @@ bool RPR::PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
}
}
// 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, TD)) {
BI = BB->begin(); // Rescan basic block. BI might be invalidated.
++NumGEPInstFormed;
return true;
}
}
// Check to see if we are casting from a structure pointer to a pointer to
// the first element of the structure... to avoid munching other peepholes,
// we only let this happen if there are no add uses of the cast.
@ -494,14 +345,6 @@ bool RPR::PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
return true;
}
} else if (I->getOpcode() == Instruction::Add &&
isa<CastInst>(I->getOperand(1))) {
if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0),
cast<CastInst>(I->getOperand(1)), TD)) {
++NumGEPInstFormed;
return true;
}
} else if (CallInst *CI = dyn_cast<CallInst>(I)) {
// If we have a call with all varargs arguments, convert the call to use the
// actual argument types present...