2003-01-31  Naveen Sharma  <naveens@noida.hcltech.com>

	* gcc/stack_reorg.c: New file.

	* gcc/Makefile.in: Add new object file (stack_reorg.o).
	GTFILES: Likewise.

	* gcc/alias.c (memrefs_conflict_p): Return zero if two distinct stack 
	slots are being checked for aliasing.

	* gcc/flags.h (flag_stack_reorg): Declare.
	(flag_new_regalloc): Add Declaration.

	* gcc/flow.c (calculate_global_regs_live): Mark all stack pseudos
	live at end of basic blocks.

	* gcc/function.c: Include target.h
	(stack_pseudo_generated): Declare and initialize.
	(assign_stack_local_1): Return a (mem:mode reg/f/c) rtx for
	a requested stack slot.
	(assign_stack_temp_for_type): Update cfun->x_initial_slot_list for
	correct debugging information.
	(find_initial_stack_offset): New Function.
	(put_reg_into_stack): Return if reg is already a stack pseudo.
	(fix_lexical_address): Handle the case when variable address in parent
	function is a stack pseudo.
	(prepare_function_start): Initialize cfun->x_initial_slot_list.

	* gcc/function.h (slot_node_def): New structure for a stack slot.
	(struct function): Add new member x_initial_slot_list.
	(find_initial_stack_offset): Declare.

	* gcc/global.c (global_alloc): Do not try to allocate stack pseudos as
	they are to be handled after register allocation.

	* gcc/local_alloc.c (local_alloc): Likewise.

	* gcc/reload.c (refers_to_regno_for_reload_p): Return if register
	is a stack pseudo.
	(reg_overlap_mentioned_for_reload_p): Likewise.

	* gcc/reload1.c: Include target.h
	(num_eliminable_invariants) : Make non static.
	(reload): Initialize max_pre_reload_pseudo. Call the stack 
	reorganization phase after pseudo registers have been assigned 
	stack slots.
	(alter_reg): Return if "i" already corresponds to stack pseudo.

	* gcc/rtl.h (rtx_def): Update comment that call flag for a REG
	would mean that it is a stack pseudo.
	(STACK_SLOT_P): New Macro.
	(int stack_reorg_completed): New extern variable.
	(stack_reorg): Declare.

	* gcc/stmt.c (expand_goto): Handle the case when non-local
	label is a stack pseudo.

	* gcc/target-def.h (TARGET_REORGANIZE_STACK_P): New Macro.
	(TARGET_INITIALIZER): Add new member TARGET_REORGANIZE_STACK_P.

	* gcc/target.h (struct gcc_target): Add reorganize_stack_p as new
	member.

	* gcc/toplev.c (flag_stack_reorg): New compiler option for initial
	testing.
	(rest_of_compilation): Reset stack_reorg_completed before finishing
	exiting.

	* gcc/config/sh/sh.c (TARGET_REORGANIZE_STACK_P): Define.
	(sh_reorganize_stack_p): New Function to enable stack reorganization.

	* gcc/doc/rtl.texi: Document use of /c flag of rtx.

	* gcc/doc/invoke.texi: Document -fstack-reorg option.

	* gcc/doc/tm.texi: Document use of TARGET_REORGANIZE_STACK_P macro.