re PR tree-optimization/20610 (Real by complex multiplications perform unnecessary...

re PR tree-optimization/20610 (Real by complex multiplications perform unnecessary operations)

        PR tree-opt/20610
        * tree.h (DECL_COMPLEX_GIMPLE_REG_P): New.
        (struct tree_decl): Add gimple_reg_flag.
        * integrate.c (copy_decl_for_inlining): Copy it.
        * gimplify.c (internal_get_tmp_var): Set it.
        (gimplify_bind_expr): Likewise.
        (gimplify_function_tree): Likewise.
        (gimplify_modify_expr_complex_part): New.
        (gimplify_modify_expr): Use it.
        * tree-gimple.c (is_gimple_reg_type): Allow complex.
        (is_gimple_reg): Allow complex with DECL_COMPLEX_GIMPLE_REG_P set.

        * tree-complex.c (complex_lattice_t): New.
        (complex_lattice_values, complex_variable_components): New.
        (some_nonzerop, find_lattice_value, is_complex_reg,
        init_parameter_lattice_values, init_dont_simulate_again,
        complex_visit_stmt, complex_visit_phi, create_components,
        update_complex_components, update_parameter_components,
        update_phi_components, update_all_vops, expand_complex_move): New.
        (extract_component): Handle INDIRECT_REF, COMPONENT_REF, ARRAY_REF,
        SSA_NAME.
        (update_complex_assignment): Use update_complex_components;
        handle updates of return_expr properly.
        (expand_complex_addition): Use complex lattice values.
        (expand_complex_multiplication): Likewise.
        (expand_complex_division): Likewise.
        (expand_complex_libcall): Use update_complex_components.
        (expand_complex_comparison): Use update_stmt.
        (expand_complex_operations_1): Use expand_complex_move, retrieve
        lattice values.
        (tree_lower_complex): Compute lattice values.
        (tree_lower_complex_O0): Duplicate from tree_lower_complex.
        (pass_lower_complex_O0): Rename from pass_lower_complex.
        (pass_lower_complex, gate_no_optimization): New.
        * tree-optimize.c (init_tree_optimization_passes): Update for
        complex pass changes.
        * tree-pass.h (pass_lower_complex_O0): Declare.

From-SVN: r100793