re PR middle-end/21265 (GCC fails to optimize tail call to memset)

re PR middle-end/21265 (GCC fails to optimize tail call to memset)

	PR middle-end/21265
	* expr.h (enum block_op_methods): Add BLOCK_OP_TAILCALL.
	(clear_storage): Add argument.
	* expr.c (emit_block_move_via_libcall, clear_storage_via_libcall):
	Add tailcall argument, set CALL_EXPR_TAILCALL of the CALL_EXPR to
	tailcall.
	(emit_block_move): Handle BLOCK_OP_TAILCALL method.
	(clear_storage): Add method argument, handle BLOCK_OP_TAILCALL.
	(store_expr, store_constructor): Adjust callers.
	* builtins.c (expand_builtin_memcpy): Pass BLOCK_OP_TAILCALL
	to emit_block_move if CALL_EXPR_TAILCALL (exp).
	(expand_builtin_memmove): Add ORIG_EXP argument, copy
	CALL_EXPR_TAILCALL from ORIG_EXP to the new CALL_EXPR.
	(expand_builtin_bcopy): Replace ARGLIST and TYPE arguments
	with EXP.  Pass EXP to expand_builtin_memmove.
	(expand_builtin_memset): Add ORIG_EXP argument, pass
	BLOCK_OP_TAILCALL to clear_storage if CALL_EXPR_TAILCALL (orig_exp).
	(expand_builtin_bzero): Replace ARGLIST argument with EXP.
	Pass EXP to expand_builtin_memset.
	(expand_builtin_strcmp): Copy CALL_EXPR_TAILCALL from EXP to
	the new CALL_EXPR.
	(expand_builtin_strncmp): Likewise.
	(expand_builtin_printf): Replace ARGLIST argument with EXP.
	Copy CALL_EXPR_TAILCALL from EXP to the new CALL_EXPR.
	(expand_builtin_fprintf): Likewise.
	(expand_builtin): Adjust calls to
	expand_builtin_{memmove,bcopy,memset,bzero,{,f}printf}.

	* gcc.dg/20050503-1.c: New test.

From-SVN: r99187