Earlier GFortran used to redefine boolean_type_node, which in the rest
of the compiler means the C/C++ _Bool/bool type, to the Fortran
default logical type.  When this redefinition was removed, a few
issues surfaced. Namely,

1) PR 82869, where we created a boolean tmp variable, and passed it to
the runtime library as a Fortran logical variable of a different size.

2) Fortran specifies that logical operations should be done with the
default logical kind, not in any other kind.

3) Using 8-bit variables have some issues, such as
   - on x86, partial register stalls and length prefix changes.
   - s390 has a compare with immediate and jump instruction which
     works with 32-bit but not 8-bit quantities.

This patch addresses these issues by introducing a type
logical_type_node which is a Fortran LOGICAL variable of default
kind. It is then used in places were the Fortran standard mandates, as
well as for compiler generated temporary variables.

For x86-64, using the Polyhedron benchmark suite, no performance or
code size difference worth mentioning was observed.

Regtested on x86_64-pc-linux-gnu.

gcc/fortran/ChangeLog:

2017-11-08  Janne Blomqvist  <jb@gcc.gnu.org>

	PR 82869
	* convert.c (truthvalue_conversion): Use logical_type_node.
	* trans-array.c (gfc_trans_allocate_array_storage): Likewise.
	(gfc_trans_create_temp_array): Likewise.
	(gfc_trans_array_ctor_element): Likewise.
	(gfc_trans_array_constructor_value): Likewise.
	(trans_array_constructor): Likewise.
	(trans_array_bound_check): Likewise.
	(gfc_conv_array_ref): Likewise.
	(gfc_trans_scalarized_loop_end): Likewise.
	(gfc_conv_array_extent_dim): Likewise.
	(gfc_array_init_size): Likewise.
	(gfc_array_allocate): Likewise.
	(gfc_trans_array_bounds): Likewise.
	(gfc_trans_dummy_array_bias): Likewise.
	(gfc_conv_array_parameter): Likewise.
	(duplicate_allocatable): Likewise.
	(duplicate_allocatable_coarray): Likewise.
	(structure_alloc_comps): Likewise
	(get_std_lbound): Likewise
	(gfc_alloc_allocatable_for_assignment): Likewise
	* trans-decl.c (add_argument_checking): Likewise
	(gfc_generate_function_code): Likewise
	* trans-expr.c (gfc_copy_class_to_class): Likewise
	(gfc_trans_class_array_init_assign): Likewise
	(gfc_trans_class_init_assign): Likewise
	(gfc_conv_expr_present): Likewise
	(gfc_conv_substring): Likewise
	(gfc_conv_cst_int_power): Likewise
	(gfc_conv_expr_op): Likewise
	(gfc_conv_procedure_call): Likewise
	(fill_with_spaces): Likewise
	(gfc_trans_string_copy): Likewise
	(gfc_trans_alloc_subarray_assign): Likewise
	(gfc_trans_pointer_assignment): Likewise
	(gfc_trans_scalar_assign): Likewise
	(fcncall_realloc_result): Likewise
	(alloc_scalar_allocatable_for_assignment): Likewise
	(trans_class_assignment): Likewise
	(gfc_trans_assignment_1): Likewise
	* trans-intrinsic.c (build_fixbound_expr): Likewise
	(gfc_conv_intrinsic_aint): Likewise
	(gfc_trans_same_strlen_check): Likewise
	(conv_caf_send): Likewise
	(trans_this_image): Likewise
	(conv_intrinsic_image_status): Likewise
	(trans_image_index): Likewise
	(gfc_conv_intrinsic_bound): Likewise
	(conv_intrinsic_cobound): Likewise
	(gfc_conv_intrinsic_mod): Likewise
	(gfc_conv_intrinsic_dshift): Likewise
	(gfc_conv_intrinsic_dim): Likewise
	(gfc_conv_intrinsic_sign): Likewise
	(gfc_conv_intrinsic_ctime): Likewise
	(gfc_conv_intrinsic_fdate): Likewise
	(gfc_conv_intrinsic_ttynam): Likewise
	(gfc_conv_intrinsic_minmax): Likewise
	(gfc_conv_intrinsic_minmax_char): Likewise
	(gfc_conv_intrinsic_anyall): Likewise
	(gfc_conv_intrinsic_arith): Likewise
	(gfc_conv_intrinsic_minmaxloc): Likewise
	(gfc_conv_intrinsic_minmaxval): Likewise
	(gfc_conv_intrinsic_btest): Likewise
	(gfc_conv_intrinsic_bitcomp): Likewise
	(gfc_conv_intrinsic_shift): Likewise
	(gfc_conv_intrinsic_ishft): Likewise
	(gfc_conv_intrinsic_ishftc): Likewise
	(gfc_conv_intrinsic_leadz): Likewise
	(gfc_conv_intrinsic_trailz): Likewise
	(gfc_conv_intrinsic_mask): Likewise
	(gfc_conv_intrinsic_spacing): Likewise
	(gfc_conv_intrinsic_rrspacing): Likewise
	(gfc_conv_intrinsic_size): Likewise
	(gfc_conv_intrinsic_sizeof): Likewise
	(gfc_conv_intrinsic_transfer): Likewise
	(gfc_conv_allocated): Likewise
	(gfc_conv_associated): Likewise
	(gfc_conv_same_type_as): Likewise
	(gfc_conv_intrinsic_trim): Likewise
	(gfc_conv_intrinsic_repeat): Likewise
	(conv_isocbinding_function): Likewise
	(conv_intrinsic_ieee_is_normal): Likewise
	(conv_intrinsic_ieee_is_negative): Likewise
	(conv_intrinsic_ieee_copy_sign): Likewise
	(conv_intrinsic_move_alloc): Likewise
	* trans-io.c (set_parameter_value_chk): Likewise
	(set_parameter_value_inquire): Likewise
	(set_string): Likewise
	* trans-openmp.c (gfc_walk_alloc_comps): Likewise
	(gfc_omp_clause_default_ctor): Likewise
	(gfc_omp_clause_copy_ctor): Likewise
	(gfc_omp_clause_assign_op): Likewise
	(gfc_omp_clause_dtor): Likewise
	(gfc_omp_finish_clause): Likewise
	(gfc_trans_omp_clauses): Likewise
	(gfc_trans_omp_do): Likewise
	* trans-stmt.c (gfc_trans_goto): Likewise
	(gfc_trans_sync): Likewise
	(gfc_trans_arithmetic_if): Likewise
	(gfc_trans_simple_do): Likewise
	(gfc_trans_do): Likewise
	(gfc_trans_forall_loop): Likewise
	(gfc_trans_where_2): Likewise
	(gfc_trans_allocate): Likewise
	(gfc_trans_deallocate): Likewise
	* trans-types.c (gfc_init_types): Initialize logical_type_node and
	its true/false trees.
	(gfc_get_array_descr_info): Use logical_type_node.
	* trans-types.h (logical_type_node): New tree.
	(logical_true_node): Likewise.
	(logical_false_node): Likewise.
	* trans.c (gfc_trans_runtime_check): Use logical_type_node.
	(gfc_call_malloc): Likewise
	(gfc_allocate_using_malloc): Likewise
	(gfc_allocate_allocatable): Likewise
	(gfc_add_comp_finalizer_call): Likewise
	(gfc_add_finalizer_call): Likewise
	(gfc_deallocate_with_status): Likewise
	(gfc_deallocate_scalar_with_status): Likewise
	(gfc_call_realloc): Likewise

gcc/testsuite/ChangeLog:

2017-11-08  Janne Blomqvist  <jb@gcc.gnu.org>

	PR 82869
	* gfortran.dg/logical_temp_io.f90: New test.
	* gfortran.dg/logical_temp_io_kind8.f90: New test.

From-SVN: r254526