What files contain what functions:

GcHeapRep1.c:  (996)
  // All actual garbage collection functions.
	collect();
	gc_task();
	scan_stacks();
	scan_thread_stacks();
	scan_globals();
	lmo_q_reset(), lmo_q_enq();
	scan_heap();
	scan_page_set();
	scan_page();
	scan_object();
	copy_obj_if_nec();

GcHeapRep2.c: (355)
  // Allocation functions.
	alloc(long, u_int);
	alloc(long, char*);
	alloc(long, int*);
	internal_alloc();
	alloc_multi_page();
	find_contig_block();
	contig_free_pages();
	expand_heap();

GcHeapRep3.c:  (151)
  // exception handling and synchronization.
	except_protect_loop();
	handle_protect_exception();
	catch_exception_raise();
	catch_exception_raise_wrk();
	wait_for_gc_done();

GcHeapRep4.c:  (509)
  // Constructor, destructor, miscellaneous.
	init();
	finalize();
	ptr2obj_head_work();
	promote_page();
	unprotect_page();
	nsq_clear();
	nsq_delete();
	nsq_enq();
	nsq_deq();
	nsq_move_to_front();
	collect_newly_free();
	reset_scanned_bits();
	PageData::init();
	...inlines when not in production mode...

GcHeap_debug.c:  (406)
  // Debugging, invariant checking, and printing functions for
  // GcHeapRep and performance measurement classes.
	GCHRepInvObj()
	~GCHRepInvObj()
	GcHeapRep::rep_inv();
	GcHeapRep::check_gc_invariants();
	ostream& operator<<(ost, GcHeapRep&);
	GcPerfObj();
	ostream& operator<<(ost, GcPerfObj&);
	GcPerfSummaryObj();
	GcPerfSummaryObj::op+=();
	ostream& operator<<(ost, GcPerfSummaryObj&);