/**
* Create a new exception handler BBLE (and exception handler basic block) for the specified
* bytecode index and exception type.
*
* @param loc bytecode index
* @param position inline sequence
* @param eType exception type
* @param temps the register pool to allocate exceptionObject from
* @param exprStackSize max size of expression stack
* @param cfg ControlFlowGraph into which the block will eventually be inserted
*/
HandlerBlockLE(
int loc,
InlineSequence position,
TypeOperand eType,
GenericRegisterPool temps,
int exprStackSize,
ControlFlowGraph cfg) {
super(loc);
entryBlock = new ExceptionHandlerBasicBlock(SYNTH_CATCH_BCI, position, eType, cfg);
block = new BasicBlock(loc, position, cfg);
// NOTE: We intentionally use throwable rather than eType to avoid
// having the complexity of having to regenerate the handler when a
// new type of caught exception is added. Since we shouldn't care about
// the performance of code in exception handling blocks, this
// should be the right tradeoff.
exceptionObject = temps.makeTemp(TypeReference.JavaLangThrowable);
BC2IR.setGuardForRegOp(exceptionObject, new TrueGuardOperand()); // know not null
high = loc;
// Set up expression stack on entry to have the caught exception operand.
stackState = new OperandStack(exprStackSize);
stackState.push(exceptionObject);
setStackKnown();
// entry block contains instructions to transfer the caught
// exception object to exceptionObject.
Instruction s = Nullary.create(GET_CAUGHT_EXCEPTION, exceptionObject.copyD2D());
entryBlock.appendInstruction(s);
s.bcIndex = SYNTH_CATCH_BCI;
entryBlock.insertOut(block);
}
/**
* Given a value number, return the temporary register allocated for that value number. Create one
* if necessary.
*
* @param heapType a TypeReference or RVMField identifying the array SSA heap type
* @param valueNumber
* @param registers a mapping from value number to temporary register
* @param pool register pool to allocate new temporaries from
* @param type the type to store in the new register
*/
static Register findOrCreateRegister(
Object heapType,
int valueNumber,
HashMap<UseRecord, Register> registers,
GenericRegisterPool pool,
TypeReference type) {
UseRecord key = new UseRecord(heapType, valueNumber);
Register result = registers.get(key);
if (result == null) {
// create a new temp and insert it in the mapping
result = pool.makeTemp(type).getRegister();
registers.put(key, result);
}
return result;
}