tree-vect-stmts.c (vectorizable_conversion): Rewritten to handle not just FLOAT_EXPR...

tree-vect-stmts.c (vectorizable_conversion): Rewritten to handle not just FLOAT_EXPR and FIX_TRUNC_EXPR...

	* tree-vect-stmts.c (vectorizable_conversion): Rewritten to handle
	not just FLOAT_EXPR and FIX_TRUNC_EXPR, but also CONVERT_EXPR_CODE_P,
	WIDEN_MULT_EXPR and WIDEN_LSHIFT_EXPR to handle what
	vectorizable_type_demotion and vectorizable_type_promotion did.
	Additionally handle FLOAT_EXPR and FIX_TRUNC_EXPR where the integer
	is {,un}signed {char,short}.
	(vect_create_vectorized_demotion_stmts): Fix comment typo.  For
	recursive calls unconditionally use VEC_PACK_TRUNC_EXPR.
	Push vec_dest back to the vec_dsts vector at the end.
	(vect_create_vectorized_promotion_stmts): Don't recurse, do just
	one step.  Removed multi_step_cvt, vec_dsts, slp_node and
	prev_stmt_info arguments, add vec_dest argument.  Push always
	into vec_tmp, not just when multi_step_cvt != 0, replace *vec_oprdn0
	with vec_tmp at the end after freeing old *vec_oprnd0 vector.
	(vectorizable_type_demotion, vectorizable_type_promotion): Removed.
	(vect_analyze_stmt): Don't call vectorizable_type_demotion and
	vectorizable_type_promotion.  Call vectorizable_conversion even
	for SLP bb vectorization.
	(vect_transform_stmt): Call vectorizable_conversion instead of
	vectorizable_type_demotion and vectorizable_type_promotion.
	(supportable_widening_operation): Clear *multi_step_cvt first,
	simplify c1/c2 computation, free *interm_types vector on failure.
	(supportable_narrowing_operation): Clear *multi_step_cvt first,
	free *interm_types vector on failure, handle multi-step
	FIX_TRUNC_EXPR.

	* gcc.dg/torture/vec-cvt-1.c: New test.

From-SVN: r180932