This patch replaces checks of "SCALAR_INT_MODE_P (...)" with
"is_a <scalar_int_mode> (..., &var)" in cases where it becomes
useful to refer to the mode as a scalar_int_mode.  It also
replaces some checks for the two constituent classes (MODE_INT
and MODE_PARTIAL_INT).

The patch also introduces is_a <scalar_int_mode> checks for some
uses of HWI_COMPUTABLE_MODE_P, which is a subcondition of
SCALAR_INT_MODE_P.

2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* wide-int.h (int_traits<unsigned char>) New class.
	(int_traits<unsigned short>) Likewise.
	* cfgexpand.c (expand_debug_expr): Use is_a <scalar_int_mode>.
	Use GET_MODE_UNIT_PRECISION and remove redundant test for
	SCALAR_INT_MODE_P.
	* combine.c (set_nonzero_bits_and_sign_copies): Use
	is_a <scalar_int_mode>.
	(find_split_point): Likewise.
	(combine_simplify_rtx): Likewise.
	(simplify_logical): Likewise.
	(expand_compound_operation): Likewise.
	(expand_field_assignment): Likewise.
	(make_compound_operation): Likewise.
	(extended_count): Likewise.
	(change_zero_ext): Likewise.
	(simplify_comparison): Likewise.
	* dwarf2out.c (scompare_loc_descriptor): Likewise.
	(ucompare_loc_descriptor): Likewise.
	(minmax_loc_descriptor): Likewise.
	(mem_loc_descriptor): Likewise.
	(loc_descriptor): Likewise.
	* expmed.c (init_expmed_one_mode): Likewise.
	* lra-constraints.c (lra_constraint_offset): Likewise.
	* optabs.c (prepare_libcall_arg): Likewise.
	* postreload.c (move2add_note_store): Likewise.
	* reload.c (operands_match_p): Likewise.
	* rtl.h (load_extend_op): Likewise.
	* rtlhooks.c (gen_lowpart_general): Likewise.
	* simplify-rtx.c (simplify_truncation): Likewise.
	(simplify_unary_operation_1): Likewise.
	(simplify_binary_operation_1): Likewise.
	(simplify_const_binary_operation): Likewise.
	(simplify_const_relational_operation): Likewise.
	(simplify_subreg): Likewise.
	* stor-layout.c (bitwise_mode_for_mode): Likewise.
	* var-tracking.c (adjust_mems): Likewise.
	(prepare_call_arguments): Likewise.

gcc/ada/
	* gcc-interface/decl.c (check_ok_for_atomic_type): Use
	is_a <scalar_int_mode>.
	* gcc-interface/trans.c (Pragma_to_gnu): Likewise.
	* gcc-interface/utils.c (gnat_type_for_mode): Likewise.

gcc/fortran/
	* trans-types.c (gfc_type_for_mode): Use is_a <scalar_int_mode>.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r251473