re PR middle-end/70434 (adding an extraneous cast to vector type results in inferior...

re PR middle-end/70434 (adding an extraneous cast to vector type results in inferior code)

2016-05-24  Richard Biener  <rguenther@suse.de>

	PR middle-end/70434
	PR c/69504
	c-family/
	* c-common.h (convert_vector_to_pointer_for_subscript): Rename to ...
	(convert_vector_to_array_for_subscript): ... this.
	* c-common.c (convert_vector_to_pointer_for_subscript): Use a
	VIEW_CONVERT_EXPR to an array type.  Rename to ...
	(convert_vector_to_array_for_subscript): ... this.

	cp/
	* expr.c (mark_exp_read): Handle VIEW_CONVERT_EXPR.
	* constexpr.c (cxx_eval_array_reference): Handle indexed
	vectors.
	* typeck.c (cp_build_array_ref): Adjust.

	c/
	* c-typeck.c (build_array_ref): Do not complain about indexing
	non-lvalue vectors.  Adjust for function name change.

	* tree-ssa.c (non_rewritable_mem_ref_base): Make sure to mark
	bases which are accessed with non-invariant indices.
	* gimple-fold.c (maybe_canonicalize_mem_ref_addr): Re-write
	constant index ARRAY_REFs of vectors into BIT_FIELD_REFs.

	* c-c++-common/vector-subscript-4.c: New testcase.
	* c-c++-common/vector-subscript-5.c: Likewise.

From-SVN: r236630