Vladimir,

This patch adds analysis in pass_final to track which hard registers are set or
clobbered by the function body, and stores that information in a
struct cgraph_node.

Thanks,
  -Tom

2013-03-30  Radovan Obradovic  <robradovic@mips.com>
            Tom de Vries  <tom@codesourcery.com>

	* cgraph.h (struct cgraph_node): Add function_used_regs,
	function_used_regs_initialized and function_used_regs_valid fields.
	* final.c: Move include of hard-reg-set.h to before rtl.h to declare
	find_all_hard_reg_sets.
	(collect_fn_hard_reg_usage, get_call_fndecl, get_call_cgraph_node)
	(get_call_reg_set_usage): New function.
	(rest_of_handle_final): Use collect_fn_hard_reg_usage.