re PR fortran/81827 (Large compile time with derived-type rrays)

re PR fortran/81827 (Large compile time with derived-type rrays)

2017-08-17  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/81827
	* tree-ssa-structalias.c (struct variable_info): Add is_reg_var
	flag.
	(new_var_info): Initialize it conservatively.
	(get_call_vi): Mark register vars.
	(new_scalar_tmp_constraint_exp): Likewise.
	(handle_rhs_call): Likewise.
	(handle_const_call): Likewise.
	(create_function_info_for): Likewise.
	(solve_constraints): Sort varinfos to separate register from
	non-register vars to pack points-to solution bitmaps during
	iteration.

From-SVN: r251143