VM.assert(VM_Allocator.isPossibleRefOrMalloc(object));
VM._assert(VM_Allocator.isPossibleRefOrMalloc(object));
    scanStackFrame(VM_Address fp, VM_Address ip, int compiledMethodId, VM_GCMapIteratorGroup iteratorGroup, VM_Thread t) {	VM_CompiledMethod compiledMethod = VM_CompiledMethods.getCompiledMethod(compiledMethodId);	VM_Method         method         = compiledMethod.getMethod();	if (GC_TRACESCANSTACK || CHECK_REF_MAPS ) {	    VM_Scheduler.outputMutex.lock(); // dfb: why is sysWrite different from all other sysWrites????	    VM.sysWrite(" ----- METHOD ----- ");	    VM.sysWrite(method.getDeclaringClass().getDescriptor());	    VM.sysWrite(".");	    VM.sysWrite(method.getName()); // instead of method.toString()	    VM.sysWrite(".\n");	    VM_Scheduler.outputMutex.unlock();	}	if (CHECK_REF_MAPS) dumpStackFrame(method, fp);	// temporary - dump contents of frame	// get stack map iterator	int offset = ip.diff(VM_Magic.objectAsAddress(compiledMethod.getInstructions()));	VM_GCMapIterator iterator = iteratorGroup.selectIterator(compiledMethod);	iterator.setupIterator (compiledMethod, offset, fp);	       	// SCAN the map and process each reference in the stack	VM_Address previousrefaddr = VM_Address.zero();	VM_Address lastrefaddr =  VM_Address.zero();	if (CHECK_REF_MAPS) {	    previousrefaddr = fp.add(VM_Compiler.getFirstLocalOffset(method) + 4);  	    // bumped first, then chked	    lastrefaddr = previousrefaddr.sub(((method.getLocalWords() + method.getOperandWords()) * 4));	    displayTopStackLoop(method, previousrefaddr, iterator);	}	if (VM_Allocator.GC_STATISTICS) VM_Allocator.numberOfStackFramesProcessed++;	int stack_ref_count = 0;	for (VM_Address refaddr = iterator.getNextReferenceAddress();  !refaddr.isZero();	     refaddr = iterator.getNextReferenceAddress()) {	    // Debug and trace support	    if (CHECK_REF_MAPS) {		stack_ref_count++;		displayRefInfo(refaddr);		previousrefaddr = displayChkRef(previousrefaddr, refaddr);	    }		   	    // If object pointer isn't null, add it to stack buffer	    VM_Address object = VM_Magic.getMemoryAddress(refaddr);	    if (!object.isZero()) {		if (VM.VerifyAssertions && ! FILTER_STACK_REFS) 		    VM.assert(VM_Allocator.isPossibleRefOrMalloc(object));		addToStackBuffer(object, t);		// can optimize by hoisting parts		if (GC_TRACESCANSTACK) stack_ref_count++;	    }	}	       	iterator.cleanupPointers();	if (CHECK_REF_MAPS) displayChkRefLast(previousrefaddr, lastrefaddr);	return stack_ref_count;    }