r178601 - in /trunk/gcc: ChangeLog tree-ssa-ali...

[rguenth@gcc.gnu.org]

Author: rguenth
Date: Tue Sep  6 15:56:20 2011
New Revision: 178601

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178601
Log:
2011-09-06  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47025
	* tree-ssa-alias.c (ref_maybe_used_by_call_p_1): BUILT_IN_VA_END
	uses nothing.
	(call_may_clobber_ref_p_1): BUILT_IN_VA_END is a barrier like
	BUILT_IN_FREE.
	(stmt_kills_ref_p_1): BUILT_IN_VA_END kills what its argument
	definitely points to.
	* tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
	BUILT_IN_VA_START doesn't let its va_list argument escape.
	* tree-ssa-dce.c (propagate_necessity): BUILT_IN_VA_END does
	not make any previous stores necessary.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-ssa-alias.c
    trunk/gcc/tree-ssa-dce.c
    trunk/gcc/tree-ssa-structalias.c