/**
* Print a getelementptr instruction.
*
* @param v the aggregate data structure to index
* @param i an iterator to the first type indexed by the instruction
* @param e an iterator specifying the upper bound on the types indexed by the
* instruction
*/
void JVMWriter::printGepInstruction(const Value *v,
gep_type_iterator i,
gep_type_iterator e) {
// load address
printCastInstruction(Instruction::IntToPtr, v, NULL, v->getType());
// calculate offset
for(; i != e; i++) {
unsigned int size = 0;
const Value *indexValue = i.getOperand();
if(const StructType *structTy = dyn_cast<StructType>(*i)) {
for(unsigned int f = 0,
fieldIndex = cast<ConstantInt>(indexValue)->getZExtValue();
f < fieldIndex; f++)
size = alignOffset(
size + targetData->getTypeAllocSize(
structTy->getContainedType(f)),
targetData->getABITypeAlignment(
structTy->getContainedType(f + 1)));
printPtrLoad(size);
printSimpleInstruction("iadd");
} else {
if(const SequentialType *seqTy = dyn_cast<SequentialType>(*i))
size = targetData->getTypeAllocSize(seqTy->getElementType());
else
size = targetData->getTypeAllocSize(*i);
if(const ConstantInt *c = dyn_cast<ConstantInt>(indexValue)) {
// constant optimisation
if(c->isNullValue()) {
// do nothing
} else if(c->getValue().isNegative()) {
printPtrLoad(c->getValue().abs().getZExtValue() * size);
printSimpleInstruction("isub");
} else {
printPtrLoad(c->getZExtValue() * size);
printSimpleInstruction("iadd");
}
} else {
printPtrLoad(size);
printCastInstruction(Instruction::IntToPtr, indexValue,
NULL, indexValue->getType());
printSimpleInstruction("imul");
printSimpleInstruction("iadd");
}
}
}
}
/**
* Print an alloca instruction.
*
* @param inst the instruction
*/
void JVMWriter::printAllocaInstruction(const AllocaInst *inst) {
uint64_t size = targetData->getTypeAllocSize(inst->getAllocatedType());
printLoadMemoryToStack( );
if(const ConstantInt *c = dyn_cast<ConstantInt>(inst->getOperand(0))) {
// constant optimization
printPtrLoad(c->getZExtValue() * size);
} else {
printPtrLoad(size);
printValueLoad(inst->getOperand(0));
printSimpleInstruction("imul");
}
printSimpleInstruction("invokevirtual",
"lljvm/runtime/Memory/allocateStack(I)I");
}
/**
* Load the given value.
*
* @param v the value to load
*/
void JVMWriter::printValueLoad(const Value *v) {
if(const Function *f = dyn_cast<Function>(v)) {
std::string sig = getValueName(f)
+ getCallSignature(f->getFunctionType());
if(externRefs.count(v))
printSimpleInstruction("CLASSFORMETHOD", sig);
else
printSimpleInstruction("ldc", '"' + classname + '"');
printSimpleInstruction("ldc", '"' + sig + '"');
printSimpleInstruction("invokestatic",
"lljvm/runtime/Function/getFunctionPointer"
"(Ljava/lang/String;Ljava/lang/String;)I");
} else if(isa<GlobalVariable>(v)) {
const Type *ty = cast<PointerType>(v->getType())->getElementType();
if(externRefs.count(v))
printSimpleInstruction("getstatic", getValueName(v) + " I");
else
printSimpleInstruction("getstatic",
classname + "/" + getValueName(v) + " I");
} else if(isa<ConstantPointerNull>(v)) {
printPtrLoad(0);
} else if(const ConstantExpr *ce = dyn_cast<ConstantExpr>(v)) {
printConstantExpr(ce);
} else if(const Constant *c = dyn_cast<Constant>(v)) {
printConstLoad(c);
} else {
if(getLocalVarNumber(v) <= 3)
printSimpleInstruction(
getTypePrefix(v->getType(), true) + "load_"
+ utostr(getLocalVarNumber(v))
+ " ; " + getValueName(v));
else
printSimpleInstruction(
getTypePrefix(v->getType(), true) + "load",
utostr(getLocalVarNumber(v))
+ " ; " + getValueName(v));
}
}
