ipa-prop.c (type_change_info): New fields offset, object, known_current_type and multiple_types_encountered.

2011-11-03  Martin Jambor  <mjambor@suse.cz>

	* ipa-prop.c (type_change_info): New fields offset, object,
	known_current_type and multiple_types_encountered.
	(extr_type_from_vtbl_ptr_store): New function.
	(check_stmt_for_type_change): Use it, set multiple_types_encountered if
        the result is different from the previous one.
	(detect_type_change): Renamed to detect_type_change_1. New parameter
	comp_type.  Set up new fields in tci, build known type jump
	functions if the new type can be identified.
	(detect_type_change): New function.
	* tree.h (DECL_CONTEXT): Comment new use.

	* testsuite/g++.dg/ipa/devirt-c-1.C: Add dump scans.
	* testsuite/g++.dg/ipa/devirt-c-2.C: Likewise.
	* testsuite/g++.dg/ipa/devirt-c-7.C: New test.
	* testsuite/g++.dg/ipa/devirt-c-8.C: Likewise.

From-SVN: r180825