This patch adds a SCALAR_TYPE_MODE macro, along the same lines as
SCALAR_INT_TYPE_MODE and SCALAR_FLOAT_TYPE_MODE.  It also adds
two instances of as_a <scalar_mode> to c_common_type, when converting
an unsigned fixed-point SCALAR_TYPE_MODE to the equivalent signed mode.

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

gcc/
	* tree.h (SCALAR_TYPE_MODE): New macro.
	* expr.c (expand_expr_addr_expr_1): Use it.
	(expand_expr_real_2): Likewise.
	* fold-const.c (fold_convert_const_fixed_from_fixed): Likeise.
	(fold_convert_const_fixed_from_int): Likewise.
	(fold_convert_const_fixed_from_real): Likewise.
	(native_encode_fixed): Likewise
	(native_encode_complex): Likewise
	(native_encode_vector): Likewise.
	(native_interpret_fixed): Likewise.
	(native_interpret_real): Likewise.
	(native_interpret_complex): Likewise.
	(native_interpret_vector): Likewise.
	* omp-simd-clone.c (simd_clone_adjust_return_type): Likewise.
	(simd_clone_adjust_argument_types): Likewise.
	(simd_clone_init_simd_arrays): Likewise.
	(simd_clone_adjust): Likewise.
	* stor-layout.c (layout_type): Likewise.
	* tree.c (build_minus_one_cst): Likewise.
	* tree-cfg.c (verify_gimple_assign_ternary): Likewise.
	* tree-inline.c (estimate_move_cost): Likewise.
	* tree-ssa-math-opts.c (convert_plusminus_to_widen): Likewise.
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Likewise.
	(vectorizable_reduction): Likewise.
	* tree-vect-patterns.c (vect_recog_widen_mult_pattern): Likewise.
	(vect_recog_mixed_size_cond_pattern): Likewise.
	(check_bool_pattern): Likewise.
	(adjust_bool_pattern): Likewise.
	(search_type_for_mask_1): Likewise.
	* tree-vect-slp.c (vect_schedule_slp_instance): Likewise.
	* tree-vect-stmts.c (vectorizable_conversion): Likewise.
	(vectorizable_load): Likewise.
	(vectorizable_store): Likewise.
	* ubsan.c (ubsan_encode_value): Likewise.
	* varasm.c (output_constant): Likewise.

gcc/c-family/
	* c-lex.c (interpret_fixed): Use SCALAR_TYPE_MODE.
	* c-common.c (c_build_vec_perm_expr): Likewise.

gcc/c/
	* c-typeck.c (build_binary_op): Use SCALAR_TYPE_MODE.
	(c_common_type): Likewise.  Use as_a <scalar_mode> when setting
	m1 and m2 to the signed equivalent of a fixed-point
	SCALAR_TYPE_MODE.

gcc/cp/
	* typeck.c (cp_build_binary_op): Use SCALAR_TYPE_MODE.

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

From-SVN: r251516

This patch adds a scalar_mode class that can hold any scalar mode,
specifically:

  - scalar integers
  - scalar floating-point values
  - scalar fractional modes
  - scalar accumulator modes
  - pointer bounds modes

To start with this patch uses this type for GET_MODE_INNER.
Later patches add more uses.

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

gcc/
	* coretypes.h (scalar_mode): New class.
	* machmode.h (scalar_mode): Likewise.
	(scalar_mode::includes_p): New function.
	(mode_to_inner): Return a scalar_mode rather than a machine_mode.
	* gdbhooks.py (build_pretty_printers): Handle scalar_mode.
	* genmodes.c (get_mode_class): Handle remaining scalar modes.
	* cfgexpand.c (expand_debug_expr): Use scalar_mode.
	* expmed.c (store_bit_field_1): Likewise.
	(extract_bit_field_1): Likewise.
	* expr.c (write_complex_part): Likewise.
	(read_complex_part): Likewise.
	(emit_move_complex_push): Likewise.
	(expand_expr_real_2): Likewise.
	* function.c (assign_parm_setup_reg): Likewise.
	(assign_parms_unsplit_complex): Likewise.
	* optabs.c (expand_binop): Likewise.
	* rtlanal.c (subreg_get_info): Likewise.
	* simplify-rtx.c (simplify_immed_subreg): Likewise.
	* varasm.c (output_constant_pool_2): Likewise.

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

From-SVN: r251515

This patch makes a few simplifications after the previous
mechanical machine_mode->scalar_int_mode change.

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

gcc/
	* expmed.c (extract_high_half): Use scalar_int_mode and remove
	assertion.
	(expmed_mult_highpart_optab): Likewise.
	(expmed_mult_highpart): Likewise.

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

From-SVN: r251514

This patch changes the types of various things from machine_mode
to scalar_int_mode, in cases where (after previous patches)
simply changing the type is enough on its own.  The patch does
nothing other than that.

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

gcc/
	* builtins.h (builtin_strncpy_read_str): Take a scalar_int_mode
	instead of a machine_mode.
	(builtin_memset_read_str): Likewise.
	* builtins.c (c_readstr): Likewise.
	(builtin_memcpy_read_str): Likewise.
	(builtin_strncpy_read_str): Likewise.
	(builtin_memset_read_str): Likewise.
	(builtin_memset_gen_str): Likewise.
	(expand_builtin_signbit): Use scalar_int_mode for local variables.
	* cfgexpand.c (convert_debug_memory_address): Take a scalar_int_mode
	instead of a machine_mode.
	* combine.c (simplify_if_then_else): Use scalar_int_mode for local
	variables.
	(make_extraction): Likewise.
	(try_widen_shift_mode): Take and return scalar_int_modes instead
	of machine_modes.
	* config/aarch64/aarch64.c (aarch64_libgcc_cmp_return_mode): Return
	a scalar_int_mode instead of a machine_mode.
	* config/avr/avr.c (avr_addr_space_address_mode): Likewise.
	(avr_addr_space_pointer_mode): Likewise.
	* config/cr16/cr16.c (cr16_unwind_word_mode): Likewise.
	* config/msp430/msp430.c (msp430_addr_space_pointer_mode): Likewise.
	(msp430_unwind_word_mode): Likewise.
	* config/spu/spu.c (spu_unwind_word_mode): Likewise.
	(spu_addr_space_pointer_mode): Likewise.
	(spu_addr_space_address_mode): Likewise.
	(spu_libgcc_cmp_return_mode): Likewise.
	(spu_libgcc_shift_count_mode): Likewise.
	* config/rl78/rl78.c (rl78_addr_space_address_mode): Likewise.
	(rl78_addr_space_pointer_mode): Likewise.
	(fl78_unwind_word_mode): Likewise.
	(rl78_valid_pointer_mode): Take a scalar_int_mode instead of a
	machine_mode.
	* config/alpha/alpha.c (vms_valid_pointer_mode): Likewise.
	* config/ia64/ia64.c (ia64_vms_valid_pointer_mode): Likewise.
	* config/mips/mips.c (mips_mode_rep_extended): Likewise.
	(mips_valid_pointer_mode): Likewise.
	* config/tilegx/tilegx.c (tilegx_mode_rep_extended): Likewise.
	* config/ft32/ft32.c (ft32_valid_pointer_mode): Likewise.
	(ft32_addr_space_pointer_mode): Return a scalar_int_mode instead
	of a machine_mode.
	(ft32_addr_space_address_mode): Likewise.
	* config/m32c/m32c.c (m32c_valid_pointer_mode): Take a
	scalar_int_mode instead of a machine_mode.
	(m32c_addr_space_pointer_mode): Return a scalar_int_mode instead
	of a machine_mode.
	(m32c_addr_space_address_mode): Likewise.
	* config/powerpcspe/powerpcspe.c (rs6000_abi_word_mode): Likewise.
	(rs6000_eh_return_filter_mode): Likewise.
	* config/rs6000/rs6000.c (rs6000_abi_word_mode): Likewise.
	(rs6000_eh_return_filter_mode): Likewise.
	* config/s390/s390.c (s390_libgcc_cmp_return_mode): Likewise.
	(s390_libgcc_shift_count_mode): Likewise.
	(s390_unwind_word_mode): Likewise.
	(s390_valid_pointer_mode): Take a scalar_int_mode rather than a
	machine_mode.
	* target.def (mode_rep_extended): Likewise.
	(valid_pointer_mode): Likewise.
	(addr_space.valid_pointer_mode): Likewise.
	(eh_return_filter_mode): Return a scalar_int_mode rather than
	a machine_mode.
	(libgcc_cmp_return_mode): Likewise.
	(libgcc_shift_count_mode): Likewise.
	(unwind_word_mode): Likewise.
	(addr_space.pointer_mode): Likewise.
	(addr_space.address_mode): Likewise.
	* doc/tm.texi: Regenerate.
	* dojump.c (prefer_and_bit_test): Take a scalar_int_mode rather than
	a machine_mode.
	(do_jump): Use scalar_int_mode for local variables.
	* dwarf2cfi.c (init_return_column_size): Take a scalar_int_mode
	rather than a machine_mode.
	* dwarf2out.c (convert_descriptor_to_mode): Likewise.
	(scompare_loc_descriptor_wide): Likewise.
	(scompare_loc_descriptor_narrow): Likewise.
	* emit-rtl.c (adjust_address_1): Use scalar_int_mode for local
	variables.
	* except.c (sjlj_emit_dispatch_table): Likewise.
	(expand_builtin_eh_copy_values): Likewise.
	* explow.c (convert_memory_address_addr_space_1): Likewise.
	Take a scalar_int_mode rather than a machine_mode.
	(convert_memory_address_addr_space): Take a scalar_int_mode rather
	than a machine_mode.
	(memory_address_addr_space): Use scalar_int_mode for local variables.
	* expmed.h (expand_mult_highpart_adjust): Take a scalar_int_mode
	rather than a machine_mode.
	* expmed.c (mask_rtx): Likewise.
	(init_expmed_one_conv): Likewise.
	(expand_mult_highpart_adjust): Likewise.
	(extract_high_half): Likewise.
	(expmed_mult_highpart_optab): Likewise.
	(expmed_mult_highpart): Likewise.
	(expand_smod_pow2): Likewise.
	(expand_sdiv_pow2): Likewise.
	(emit_store_flag_int): Likewise.
	(adjust_bit_field_mem_for_reg): Use scalar_int_mode for local
	variables.
	(extract_low_bits): Likewise.
	* expr.h (by_pieces_constfn): Take a scalar_int_mode rather than
	a machine_mode.
	* expr.c (pieces_addr::adjust):  Likewise.
	(can_store_by_pieces): Likewise.
	(store_by_pieces): Likewise.
	(clear_by_pieces_1): Likewise.
	(expand_expr_addr_expr_1): Likewise.
	(expand_expr_addr_expr): Use scalar_int_mode for local variables.
	(expand_expr_real_1): Likewise.
	(try_casesi): Likewise.
	* final.c (shorten_branches): Likewise.
	* fold-const.c (fold_convert_const_int_from_fixed): Change the
	type of "mode" to machine_mode.
	* internal-fn.c (expand_arith_overflow_result_store): Take a
	scalar_int_mode rather than a machine_mode.
	(expand_mul_overflow): Use scalar_int_mode for local variables.
	* loop-doloop.c (doloop_modify): Likewise.
	(doloop_optimize): Likewise.
	* optabs.c (expand_subword_shift): Take a scalar_int_mode rather
	than a machine_mode.
	(expand_doubleword_shift_condmove): Likewise.
	(expand_doubleword_shift): Likewise.
	(expand_doubleword_clz): Likewise.
	(expand_doubleword_popcount): Likewise.
	(expand_doubleword_parity): Likewise.
	(expand_absneg_bit): Use scalar_int_mode for local variables.
	(prepare_float_lib_cmp): Likewise.
	* rtl.h (convert_memory_address_addr_space_1): Take a scalar_int_mode
	rather than a machine_mode.
	(convert_memory_address_addr_space): Likewise.
	(get_mode_bounds): Likewise.
	(get_address_mode): Return a scalar_int_mode rather than a
	machine_mode.
	* rtlanal.c (get_address_mode): Likewise.
	* stor-layout.c (get_mode_bounds): Take a scalar_int_mode rather
	than a machine_mode.
	* targhooks.c (default_mode_rep_extended): Likewise.
	(default_valid_pointer_mode): Likewise.
	(default_addr_space_valid_pointer_mode): Likewise.
	(default_eh_return_filter_mode): Return a scalar_int_mode rather
	than a machine_mode.
	(default_libgcc_cmp_return_mode): Likewise.
	(default_libgcc_shift_count_mode): Likewise.
	(default_unwind_word_mode): Likewise.
	(default_addr_space_pointer_mode): Likewise.
	(default_addr_space_address_mode): Likewise.
	* targhooks.h (default_eh_return_filter_mode): Likewise.
	(default_libgcc_cmp_return_mode): Likewise.
	(default_libgcc_shift_count_mode): Likewise.
	(default_unwind_word_mode): Likewise.
	(default_addr_space_pointer_mode): Likewise.
	(default_addr_space_address_mode): Likewise.
	(default_mode_rep_extended): Take a scalar_int_mode rather than
	a machine_mode.
	(default_valid_pointer_mode): Likewise.
	(default_addr_space_valid_pointer_mode): Likewise.
	* tree-ssa-address.c (addr_for_mem_ref): Use scalar_int_mode for
	local variables.
	* tree-ssa-loop-ivopts.c (get_shiftadd_cost): Take a scalar_int_mode
	rather than a machine_mode.
	* tree-switch-conversion.c (array_value_type): Use scalar_int_mode
	for local variables.
	* tree-vrp.c (simplify_float_conversion_using_ranges): Likewise.
	* var-tracking.c (use_narrower_mode): Take a scalar_int_mode rather
	than a machine_mode.

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

From-SVN: r251513

The callers of do_jump_by_parts_* had already established
that the modes were MODE_INTs, so this patch passes the
modes down as scalar_int_modes.

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

gcc/
	* dojump.c (do_jump_by_parts_greater_rtx): Change the type of
	the mode argument to scalar_int_mode.
	(do_jump_by_parts_zero_rtx): Likewise.
	(do_jump_by_parts_equality_rtx): Likewise.
	(do_jump_by_parts_greater): Take a mode argument.
	(do_jump_by_parts_equality): Likewise.
	(do_jump_1): Update calls accordingly.

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

From-SVN: r251512

This patch adds a helper function to get the mode of the addresses
or offsets in a jump table.  It also changes the final.c code to use
rtx_jump_table_data over rtx or rtx_insn in cases where it needed
to use the new helper.  This in turn meant adding a safe_dyn_cast
equivalent of safe_as_a, to cope with null NEXT_INSNs.

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

gcc/
	* is-a.h (safe_dyn_cast): New function.
	* rtl.h (rtx_jump_table_data::get_data_mode): New function.
	(jump_table_for_label): Likewise.
	* final.c (final_addr_vec_align): Take an rtx_jump_table_data *
	instead of an rtx_insn *.
	(shorten_branches): Use dyn_cast instead of LABEL_P and
	JUMP_TABLE_DATA_P.  Use jump_table_for_label and
	rtx_jump_table_data::get_data_mode.
	(final_scan_insn): Likewise.

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

From-SVN: r251511

This patch uses scalar_int_modes for:

  /* If I2 is setting a pseudo to a constant and I3 is setting some
     sub-part of it to another constant, merge them by making a new
     constant.  */

This was already implicit, but the danger with checking only
CONST_SCALAR_INT_P is that it can include CC values too.

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

gcc/
	* combine.c (try_combine): Use is_a <scalar_int_mode> when
	trying to combine a full-register integer set with a subreg
	integer set.

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

From-SVN: r251510

This patch rewrites the condition:

  if (tmode != address_mode && tmode != pointer_mode)
    tmode = address_mode;

to the equivalent:

  tmode == pointer_mode ? pointer_mode : address_mode

The latter has the advantage that the result is naturally
a scalar_int_mode; a later mechanical patch makes it one.

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

gcc/
	* expr.c (expand_expr_addr_expr): Add a new_tmode local variable
	that is always either address_mode or pointer_mode.

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

From-SVN: r251509

This patch adjusts a couple of cases in which we had established
that two modes were equal and happened to be using the one with the
more general type instead of the one with the more specific type.

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

gcc/
	* expr.c (expand_expr_real_2): Use word_mode instead of innermode
	when the two are known to be equal.

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

From-SVN: r251508

The main scalar integer block in simplify_const_unary_operation
had the condition:

  if (CONST_SCALAR_INT_P (op) && width > 0)

where "width > 0" was a roundabout way of testing != VOIDmode.
This patch replaces it with a check for a scalar_int_mode instead.
It also uses the number of bits in the input rather than the output
mode to determine the result of a "count ... bits in zero" operation.
(At the momemnt these modes have to be the same, but it still seems
conceptually wrong to use the number of bits in the output mode.)

The handling of float->integer ops also checked "width > 0",
but this was redundant with the earlier check for MODE_INT.

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

gcc/
	* simplify-rtx.c (simplify_const_unary_operation): Use
	is_a <scalar_int_mode> instead of checking for a nonzero
	precision.  Forcibly convert op_mode to a scalar_int_mode
	in that case.  More clearly differentiate the operand and
	result modes and use the former when deciding what the value
	of a count-bits operation should be.  Use is_int_mode instead
	of checking for a MODE_INT.  Remove redundant check for whether
	this mode has a zero precision.

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

From-SVN: r251507

expand_unop can expand narrow clz, clrsb, ctz, bswap, parity and
ffs operations using optabs for wider modes.  These expansions
apply only to scalar integer modes (and not for example to vectors),
so the patch adds explicit checks for that.

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

gcc/
	* optabs.c (widen_leading): Change the type of the mode argument
	to scalar_int_mode.  Use opt_scalar_int_mode for the mode iterator.
	(widen_bswap): Likewise.
	(expand_parity): Likewise.
	(expand_ctz): Change the type of the mode argument to scalar_int_mode.
	(expand_ffs): Likewise.
	(epand_unop): Check for scalar integer modes before calling the
	above routines.

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

From-SVN: r251506

The caller of const_scalar_mask_from_tree has proven that
the mode is a MODE_INT, so this patch passes it down as a
scalar_int_mode.  It also expands the comment a little.

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

gcc/
	* expr.c (const_scalar_mask_from_tree): Add a mode argument.
	Expand commentary.
	(expand_expr_real_1): Update call accordingly.

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

From-SVN: r251505

After a certain point, extract_bit_field and store_bit_field
ensure that they're dealing with integer modes or BLKmode MEMs.
This patch uses scalar_int_mode and opt_scalar_int_mode for
those parts.

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

gcc/
	* expmed.c (store_bit_field_using_insv): Add op0_mode and
	value_mode arguments.  Use scalar_int_mode internally.
	(store_bit_field_1): Rename the new integer mode from imode
	to op0_mode and use it instead of GET_MODE (op0).  Update calls
	to store_split_bit_field, store_bit_field_using_insv and
	store_fixed_bit_field.
	(store_fixed_bit_field): Add op0_mode and value_mode arguments.
	Use scalar_int_mode internally.  Use a bit count rather than a mode
	when calculating the largest bit size for get_best_mode.
	Update calls to store_split_bit_field and store_fixed_bit_field_1.
	(store_fixed_bit_field_1): Add mode and value_mode arguments.
	Remove assertion that OP0 has a scalar integer mode.
	(store_split_bit_field): Add op0_mode and value_mode arguments.
	Update calls to extract_fixed_bit_field.
	(extract_bit_field_using_extv): Add an op0_mode argument.
	Use scalar_int_mode internally.
	(extract_bit_field_1): Rename the new integer mode from imode to
	op0_mode and use it instead of GET_MODE (op0).  Update calls to
	extract_split_bit_field, extract_bit_field_using_extv and
	extract_fixed_bit_field.
	(extract_fixed_bit_field): Add an op0_mode argument.  Update calls
	to extract_split_bit_field and extract_fixed_bit_field_1.
	(extract_fixed_bit_field_1): Add a mode argument.  Remove assertion
	that OP0 has a scalar integer mode.  Use as_a <scalar_int_mode>
	on the target mode.
	(extract_split_bit_field): Add an op0_mode argument.  Update call
	to extract_fixed_bit_field.

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

From-SVN: r251504

This patch uses opt_scalar_int_mode rather than machine_mode
when iterating over scalar_int_modes, in cases where that helps
with future patches.  (Using machine_mode is still OK in places
that don't really care about the mode being a scalar integer.)

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

gcc/
	* cse.c (cse_insn): Use opt_scalar_int_mode for the mode iterator.
	* explow.c (hard_function_value): Likewise.
	* expmed.c (extract_fixed_bit_field_1): Likewise.  Move the
	convert_to_mode call outside the loop.
	* expr.c (alignment_for_piecewise_move): Use opt_scalar_int_mode
	for the mode iterator.  Require the mode specified by max_pieces
	to exist.
	(emit_block_move_via_movmem): Use opt_scalar_int_mode for the
	mode iterator.
	(copy_blkmode_to_reg): Likewise.
	(set_storage_via_setmem): Likewise.
	* optabs.c (prepare_cmp_insn): Likewise.
	* rtlanal.c (init_num_sign_bit_copies_in_rep): Likewise.
	* stor-layout.c (finish_bitfield_representative): Likewise.

gcc/fortran/
	* trans-types.c (gfc_init_kinds): Use opt_scalar_int_mode for
	the mode iterator.

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

From-SVN: r251503

When subregs contain promoted values, as indicated by
SUBREG_PROMOTED_VAR_P, both the unpromoted (outer) and
promoted (inner) values are known to be scalar integers.
This patch adds helper routines that get the modes as
scalar_int_modes.

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

gcc/
	* rtl.h (subreg_unpromoted_mode, subreg_promoted_mode): New functions.
	* expr.c (convert_move): Use them.
	(convert_modes): Likewise.
	(store_expr_with_bounds): Likewise.

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

From-SVN: r251502

The two implementations of the reg_nonzero_bits and reg_num_sign_bits
hooks ignored the "known_x", "known_mode" and "known_ret" arguments,
so this patch removes them.  It adds a new scalar_int_mode parameter
that specifies the mode of "x".  (This mode might be different from
"mode", which is the mode in which "x" is used.)

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

gcc/
	* rtl.h (rtl_hooks::reg_nonzero_bits): Add a scalar_int_mode
	parameter for the mode of "x".  Remove the "known_x", "known_mode"
	and "known_ret" arguments.  Change the type of the mode argument
	to scalar_int_mode.
	(rtl_hooks:reg_num_sign_bit_copies): Likewise.
	* combine.c (reg_nonzero_bits_for_combine): Update accordingly.
	(reg_num_sign_bit_copies_for_combine): Likewise.
	* rtlanal.c (nonzero_bits1): Likewise.
	(num_sign_bit_copies1): Likewise.
	* rtlhooks-def.h (reg_nonzero_bits_general): Likewise.
	(reg_num_sign_bit_copies_general): Likewise.
	* rtlhooks.c (reg_num_sign_bit_copies_general): Likewise.
	(reg_nonzero_bits_general): Likewise.

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

From-SVN: r251501

Similarly to the nonzero_bits patch, this one moves the mode
class check and VOIDmode handling from num_sign_bit_copies1
to num_sign_bit_copies itself, then changes the subroutines
to operate on scalar_int_modes.

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

gcc/
	* rtlanal.c (num_sign_bit_copies): Handle VOIDmode here rather
	than in subroutines.  Return 1 for non-integer modes.
	(cached_num_sign_bit_copies): Change the type of the mode parameter
	to scalar_int_mode.
	(num_sign_bit_copies1): Likewise.  Remove early exit for other mode
	classes.  Handle CONST_INT_P first and then check whether X also
	has a scalar integer mode.  Check the same thing for inner registers
	of a SUBREG and for values that are being extended or truncated.

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

From-SVN: r251500

nonzero_bits1 assumed that all bits of a floating-point or vector mode
were needed.  It seems likely that fixed-point modes should have been
handled in the same way.  After excluding those, the only remaining
modes that are likely to be useful are scalar integer ones.

This patch moves the mode class check to nonzero_bits itself, along
with the handling of mode == VOIDmode.  The subroutines of nonzero_bits
can then take scalar_int_modes.

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

gcc/
	* rtlanal.c (nonzero_bits): Handle VOIDmode here rather than
	in subroutines.  Return the mode mask for non-integer modes.
	(cached_nonzero_bits): Change the type of the mode parameter
	to scalar_int_mode.
	(nonzero_bits1): Likewise.  Remove early exit for other mode
	classes.  Handle CONST_INT_P first and then check whether X
	also has a scalar integer mode.

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

From-SVN: r251499

The comment for widest_int_mode said that it returns "the widest integer
mode no wider than SIZE", but it actually returns the widest integer
mode that is narrower than SIZE.  In practice SIZE is always greater
than 1, so it can always pick QImode in the worst case.  The VOIDmode
paths seem to be dead.

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

	* expr.c (widest_int_mode_for_size): Make the comment match the code.
	Return a scalar_int_mode and assert that the size is greater than
	one byte.
	(by_pieces_ninsns): Update accordingly and remove VOIDmode handling.
	(op_by_pieces_d::op_by_pieces_d): Likewise.
	(op_by_pieces_d::run): Likewise.
	(can_store_by_pieces): Likewise.

From-SVN: r251498

This patch passes the mode of the shifted value to extract_left_shift
and updates the only caller so that the mode is a scalar_int_mode.

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

gcc/
	* combine.c (extract_left_shift): Add a mode argument and update
	recursive calls.
	(make_compound_operation_int): Change the type of the mode parameter
	to scalar_int_mode and update the call to extract_left_shift.

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

From-SVN: r251497

After previous patches, top-level calls to simplify_and_const_int
always pass a scalar_int_mode.  The only call site that needs to
be updated is the recursive one in simplify_and_const_int_1,
at which point we know "varop" has a scalar integer mode.

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

gcc/
	* combine.c (simplify_and_const_int): Change the type of the mode
	parameter to scalar_int_mode.
	(simplify_and_const_int_1): Likewise.  Update recursive call.

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

From-SVN: r251496

The main loop of simplify_comparison starts with:

      if (GET_MODE_CLASS (mode) != MODE_INT
          && ! (mode == VOIDmode
                && (GET_CODE (op0) == COMPARE || COMPARISON_P (op0))))
        break;

So VOIDmode is only acceptable when comparing a COMPARE,
EQ, NE, etc. operand against a constant.  After this, the loop
calls simplify_compare_const to:

  (a) bring the constant op1 closer to 0 where possible and
  (b) use nonzero_bits and num_sign_bit_copies to get a simpler
      constant.

(a) works for both integer and VOID modes, (b) is specific
to integer modes.

The loop then has a big switch statement that handles further
simplifications.  This switch statement checks for COMPARISON_P
codes but not for COMPARE.

This patch uses scalar_int_mode to make the split between
(a) and (b) more explicit.  It also takes the COMPARISON_P
handling out of the switch statement and does it first,
so that the rest of the loop can treat the mode as a
scalar_int_mode.

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

gcc/
	* combine.c (simplify_compare_const): Check that the mode is a
	scalar_int_mode (rather than VOIDmode) before testing its
	precision.
	(simplify_comparison): Move COMPARISON_P handling out of the
	loop and restrict the latter part of the loop to scalar_int_modes.
	Check is_a <scalar_int_mode> before calling HWI_COMPUTABLE_MODE_P
	and when considering SUBREG_REGs.  Use is_int_mode instead of
	checking GET_MODE_CLASS against MODE_INT.

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

From-SVN: r251495

This patch makes simplify_shift_const_1 use scalar_int_modes
for all code that is specific to scalars rather than vectors.
This includes situations in which the new shift mode is different
from the original one, since the function never changes the mode
of vector shifts.  That in turn makes it more natural to test for
equal modes in simplify_shift_const_1 rather than try_widen_shift_mode
(which only applies to scalars).

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

gcc/
	* combine.c (try_widen_shift_mode): Move check for equal modes to...
	(simplify_shift_const_1): ...here.  Use scalar_int_mode for
	shift_unit_mode and for modes involved in scalar shifts.

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

From-SVN: r251494

force_to_mode exits partway through for modes that aren't scalar
integers.  This patch splits the remainder of the function out
into a subroutine, force_int_to_mode, so that the modes from that
point on can have type scalar_int_mode.

The patch also makes sure that xmode is kept up-to-date with x
and uses xmode instead of GET_MODE (x) throughout.

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

gcc/
	* combine.c (force_int_to_mode): New function, split out from...
	(force_to_mode): ...here.  Keep xmode up-to-date and use it
	instead of GET_MODE (x).

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

From-SVN: r251493

insv, extv and eztzv modify or read a field in a register or
memory.  The field always has a scalar integer mode, while the
register or memory either has a scalar integer mode or BLKmode.
The mode of the bit position is also a scalar integer.

This patch uses the type system to make that explicit.

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

gcc/
	* optabs-query.h (extraction_insn::struct_mode): Change type to
	opt_scalar_int_mode and update comment.
	(extraction_insn::field_mode): Change type to scalar_int_mode.
	(extraction_insn::pos_mode): Likewise.
	* combine.c (make_extraction): Update accordingly.
	* optabs-query.c (get_traditional_extraction_insn): Likewise.
	(get_optab_extraction_insn): Likewise.
	* recog.c (simplify_while_replacing): Likewise.
	* expmed.c (narrow_bit_field_mem): Change the type of the mode
	parameter to opt_scalar_int_mode.

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

From-SVN: r251492

get_best_mode always returns a scalar_int_mode on success,
so this patch makes that explicit in the type system.  Also,
the "largest_mode" argument is used simply to provide a maximum
size, and in practice that size is always a compile-time constant,
even when the concept of variable-sized modes is added later.
The patch therefore passes the size directly.

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

gcc/
	* machmode.h (bit_field_mode_iterator::next_mode): Take a pointer
	to a scalar_int_mode instead of a machine_mode.
	(bit_field_mode_iterator::m_mode): Change type to opt_scalar_int_mode.
	(get_best_mode): Return a boolean and use a pointer argument to store
	the selected mode.  Replace the limit mode parameter with a bit limit.
	* expmed.c (adjust_bit_field_mem_for_reg): Use scalar_int_mode
	for the values returned by bit_field_mode_iterator::next_mode.
	(store_bit_field): Update call to get_best_mode.
	(store_fixed_bit_field): Likewise.
	(extract_fixed_bit_field): Likewise.
	* expr.c (optimize_bitfield_assignment_op): Likewise.
	* fold-const.c (optimize_bit_field_compare): Likewise.
	(fold_truth_andor_1): Likewise.
	* stor-layout.c (bit_field_mode_iterator::next_mode): As above.
	Update for new type of m_mode.
	(get_best_mode): As above.

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

From-SVN: r251491

strict_volatile_bitfield_p returns false for any mode that isn't
a scalar integer.  This patch moves the check to the caller and
makes strict_volatile_bitfield_p take the mode as a scalar_int_mode.
The handling of a true return can then also use the mode as a
scalar_int_mode.

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

gcc/
	* expmed.c (strict_volatile_bitfield_p): Change the type of fieldmode
	to scalar_int_mode.  Remove check for SCALAR_INT_MODE_P.
	(store_bit_field): Check is_a <scalar_int_mode> before calling
	strict_volatile_bitfield_p.
	(extract_bit_field): Likewise.

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

From-SVN: r251490

cstore patterns always have a scalar integer result, which has the
value 0 for "false" and STORE_FLAG_VALUE for "true".  This patch
makes that explicit using scalar_int_mode.

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

gcc/
	* target.def (cstore_mode): Return a scalar_int_mode.
	* doc/tm.texi: Regenerate.
	* config/sparc/sparc.c (sparc_cstore_mode): Return a scalar_int_mode.
	* targhooks.h (default_cstore_mode): Likewise.
	* targhooks.c (default_cstore_mode): Likewise, using a forced
	conversion.
	* expmed.c (emit_cstore): Expect the target of the cstore to be
	a scalar_int_mode.

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

From-SVN: r251489

This patch changes the iv modes in rtx_iv from machine_mode
to scalar_int_mode.  It also passes the mode of the iv down
to subroutines; this avoids the previous situation in which
the mode information was sometimes lost and had to be added
by the caller on return.

Some routines already took a mode argument, but the patch
tries to standardise on passing it immediately before the
argument it describes.

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

	* cfgloop.h (rtx_iv): Change type of extend_mode and mode to
	scalar_int_mode.
	(niter_desc): Likewise mode.
	(iv_analyze): Add a mode parameter.
	(biv_p): Likewise.
	(iv_analyze_expr): Pass the mode paraeter before the rtx it describes
	and change its type to scalar_int_mode.
	* loop-iv.c: Update commentary at head of file.
	(iv_constant): Pass the mode paraeter before the rtx it describes
	and change its type to scalar_int_mode.  Remove VOIDmode handling.
	(iv_subreg): Change the type of the mode parameter to scalar_int_mode.
	(iv_extend): Likewise.
	(shorten_into_mode): Likewise.
	(iv_add): Use scalar_int_mode.
	(iv_mult): Likewise.
	(iv_shift): Likewise.
	(canonicalize_iv_subregs): Likewise.
	(get_biv_step_1): Pass the outer_mode parameter before the rtx
	it describes and change its mode to scalar_int_mode.   Also change
	the type of the returned inner_mode to scalar_int_mode.
	(get_biv_step): Likewise, turning outer_mode from a pointer
	into a direct parameter.  Update call to get_biv_step_1.
	(iv_analyze_biv): Add an outer_mode parameter.  Update calls to
	iv_constant and get_biv_step.
	(iv_analyze_expr): Pass the mode parameter before the rtx it describes
	and change its type to scalar_int_mode.  Don't initialise iv->mode
	to VOIDmode and remove later checks for its still being VOIDmode.
	Update calls to iv_analyze_op and iv_analyze_expr.  Check
	is_a <scalar_int_mode> when changing the mode under consideration.
	(iv_analyze_def): Ignore registers that don't have a scalar_int_mode.
	Update call to iv_analyze_expr.
	(iv_analyze_op): Add a mode parameter.  Reject subregs whose
	inner register is not also a scalar_int_mode.  Update call to
	iv_analyze_biv.
	(iv_analyze): Add a mode parameter.  Update call to iv_analyze_op.
	(biv_p): Add a mode parameter.  Update call to iv_analyze_biv.
	(iv_number_of_iterations): Use is_a <scalar_int_mode> instead of
	separate mode class checks.  Update calls to iv_analyze.  Remove
	fix-up of VOIDmodes after iv_analyze_biv.
	* loop-unroll.c (analyze_iv_to_split_insn): Reject registers that
	don't have a scalar_int_mode.  Update call to biv_p.

From-SVN: r251488

This patch adds asserting as_a <scalar_int_mode> conversions
to contexts in which the input is known to be a scalar integer mode.

In expand_divmod, op1 is always a scalar_int_mode if
op1_is_constant (but might not be otherwise).

In expand_binop, the patch reverses a < comparison in order to
avoid splitting a long line.

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

	* cfgexpand.c (convert_debug_memory_address): Use
	as_a <scalar_int_mode>.
	* combine.c (expand_compound_operation): Likewise.
	(make_extraction): Likewise.
	(change_zero_ext): Likewise.
	(simplify_comparison): Likewise.
	* cse.c (cse_insn): Likewise.
	* dwarf2out.c (minmax_loc_descriptor): Likewise.
	(mem_loc_descriptor): Likewise.
	(loc_descriptor): Likewise.
	* expmed.c (init_expmed_one_mode): Likewise.
	(synth_mult): Likewise.
	(emit_store_flag_1): Likewise.
	(expand_divmod): Likewise.  Use HWI_COMPUTABLE_MODE_P instead
	of a comparison with size.
	* expr.c (expand_assignment): Use as_a <scalar_int_mode>.
	(reduce_to_bit_field_precision): Likewise.
	* function.c (expand_function_end): Likewise.
	* internal-fn.c (expand_arith_overflow_result_store): Likewise.
	* loop-doloop.c (doloop_modify): Likewise.
	* optabs.c (expand_binop): Likewise.
	(expand_unop): Likewise.
	(expand_copysign_absneg): Likewise.
	(prepare_cmp_insn): Likewise.
	(maybe_legitimize_operand): Likewise.
	* recog.c (const_scalar_int_operand): Likewise.
	* rtlanal.c (get_address_mode): Likewise.
	* simplify-rtx.c (simplify_unary_operation_1): Likewise.
	(simplify_cond_clz_ctz): Likewise.
	* tree-nested.c (get_nl_goto_field): Likewise.
	* tree.c (build_vector_type_for_mode): Likewise.
	* var-tracking.c (use_narrower_mode): Likewise.

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

	* c-common.c (c_common_type_for_mode): Use as_a <scalar_int_mode>.

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

	* lto-lang.c (lto_type_for_mode): Use as_a <scalar_int_mode>.

From-SVN: r251487

This patch adds a SCALAR_INT_TYPE_MODE macro that asserts
that the type has a scalar integer mode and returns it as
a scalar_int_mode.

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

gcc/
	* tree.h (SCALAR_INT_TYPE_MODE): New macro.
	* builtins.c (expand_builtin_signbit): Use it.
	* cfgexpand.c (expand_debug_expr): Likewise.
	* dojump.c (do_jump): Likewise.
	(do_compare_and_jump): Likewise.
	* dwarf2cfi.c (expand_builtin_init_dwarf_reg_sizes): Likewise.
	* expmed.c (make_tree): Likewise.
	* expr.c (expand_expr_real_2): Likewise.
	(expand_expr_real_1): Likewise.
	(try_casesi): Likewise.
	* fold-const-call.c (fold_const_call_ss): Likewise.
	* fold-const.c (unextend): Likewise.
	(extract_muldiv_1): Likewise.
	(fold_single_bit_test): Likewise.
	(native_encode_int): Likewise.
	(native_encode_string): Likewise.
	(native_interpret_int): Likewise.
	* gimple-fold.c (gimple_fold_builtin_memset): Likewise.
	* internal-fn.c (expand_addsub_overflow): Likewise.
	(expand_neg_overflow): Likewise.
	(expand_mul_overflow): Likewise.
	(expand_arith_overflow): Likewise.
	* match.pd: Likewise.
	* stor-layout.c (layout_type): Likewise.
	* tree-cfg.c (verify_gimple_assign_ternary): Likewise.
	* tree-ssa-math-opts.c (convert_mult_to_widen): Likewise.
	* tree-ssanames.c (get_range_info): Likewise.
	* tree-switch-conversion.c (array_value_type) Likewise.
	* tree-vect-patterns.c (vect_recog_rotate_pattern): Likewise.
	(vect_recog_divmod_pattern): Likewise.
	(vect_recog_mixed_size_cond_pattern): Likewise.
	* tree-vrp.c (extract_range_basic): Likewise.
	(simplify_float_conversion_using_ranges): Likewise.
	* tree.c (int_fits_type_p): Likewise.
	* ubsan.c (instrument_bool_enum_load): Likewise.
	* varasm.c (mergeable_string_section): Likewise.
	(narrowing_initializer_constant_valid_p): Likewise.
	(output_constant): Likewise.

gcc/cp/
	* cvt.c (cp_convert_to_pointer): Use SCALAR_INT_TYPE_MODE.

gcc/fortran/
	* target-memory.c (size_integer): Use SCALAR_INT_TYPE_MODE.
	(size_logical): Likewise.

gcc/objc/
	* objc-encoding.c (encode_type): Use SCALAR_INT_TYPE_MODE.

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

From-SVN: r251486

This patch replaces uses of GET_CLASS_NARROWEST_MODE (MODE_INT) with a
new NARROWEST_INT_MODE macro, which has type scalar_int_mode.

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

gcc/
	* machmode.h (NARROWEST_INT_MODE): New macro.
	* expr.c (alignment_for_piecewise_move): Use it instead of
	GET_CLASS_NARROWEST_MODE (MODE_INT).
	(push_block): Likewise.
	* stor-layout.c (bit_field_mode_iterator::bit_field_mode_iterator):
	Likewise.
	* tree-vrp.c (simplify_float_conversion_using_ranges): Likewise.

gcc/ada/
	* gcc-interface/decl.c (validate_size): Use NARROWEST_INT_MODE
	instead of GET_CLASS_NARROWEST_MODE (MODE_INT).

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

From-SVN: r251485

A future patch will make valid_pointer_mode take a scalar_int_mode
instead of a machine_mode.  is_a <...> rather than as_a <...> is
needed here because we're checking a mode supplied by the user.

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

gcc/c-family/
	* c-attribs.c (handle_mode_attribute): Check for a scalar_int_mode
	before calling targetm.addr_space.valid_pointer_mode.

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

From-SVN: r251484

The postreload move2add optimisations are specific to scalar
integers.  This patch adds an explicit check to the main guarding
"if" and propagates the information through subroutines.

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

	* postreload.c (move2add_valid_value_p): Change the type of the
	mode parameter to scalar_int_mode.
	(move2add_use_add2_insn): Add a mode parameter and use it instead
	of GET_MODE (reg).
	(move2add_use_add3_insn): Likewise.
	(reload_cse_move2add): Update accordingly.

From-SVN: r251483

This patch uses is_a <scalar_int_mode> in a couple of places that
were splitting doubleword integer operations into word_mode
operations.  It also uses scalar_int_mode in the expand_expr_real_2
handling of doubleword shifts.

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

gcc/
	* expr.c (expand_expr_real_2): Use scalar_int_mode for the
	double-word mode.
	* lower-subreg.c (resolve_shift_zext): Use is_a <scalar_int_mode>.
	* optabs.c (expand_unop): Likewise.

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

From-SVN: r251482

The *_loc_descriptor routines for clz, popcount, bswap and rotate
all required SCALAR_INT_MODE_P.  This patch moves the checks into
the caller (mem_loc_descriptor) so that the types of the mode
parameters can be scalar_int_mode instead of machine_mode.

The MOD handling in mem_loc_descriptor is also specific to
scalar integer modes.  Adding an explicit check allows
typed_binop to take a scalar_int_mode too.

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

gcc/
	* dwarf2out.c (typed_binop): Change mode parameter to scalar_int_mode.
	(clz_loc_descriptor): Likewise.  Remove SCALAR_INT_MODE_P check.
	(popcount_loc_descriptor): Likewise.
	(bswap_loc_descriptor): Likewise.
	(rotate_loc_descriptor): Likewise.
	(mem_loc_descriptor): Add is_a <scalar_int_mode> checks before
	calling the functions above.

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

From-SVN: r251481

This patch adds is_a <scalar_int_mode> checks to various places
that were explicitly or implicitly restricted to integers already,
in cases where adding an explicit is_a <scalar_int_mode> is useful
for later patches.

In simplify_if_then_else, the:

  GET_MODE (XEXP (XEXP (t, 0), N))

expressions were equivalent to:

  GET_MODE (XEXP (t, 0))

due to the type of operation.

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

gcc/
	* combine.c (sign_extend_short_imm): Add is_a <scalar_int_mode>
	checks.
	(try_combine): Likewise.
	(simplify_if_then_else): Likewise.
	* cse.c (cse_insn): Likewise.
	* dwarf2out.c (mem_loc_descriptor): Likewise.
	* emit-rtl.c (gen_lowpart_common): Likewise.
	* simplify-rtx.c (simplify_truncation): Likewise.
	(simplify_binary_operation_1): Likewise.
	(simplify_const_relational_operation): Likewise.
	(simplify_ternary_operation): Likewise.
	* tree-ssa-loop-ivopts.c (force_expr_to_var_cost): Likewise.

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

From-SVN: r251480

This patch adds is_a <scalar_int_mode> checks before load_extend_op/
LOAD_EXTEND_OP calls, if that becomes useful for later patches.
(load_extend_op will return UNKNOWN for any other type of mode.)

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

gcc/
	* cse.c (cse_insn): Add is_a <scalar_int_mode> checks.
	* reload.c (push_reload): Likewise.
	(find_reloads): Likewise.

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

From-SVN: r251479

This patch adds is_a <scalar_int_mode> checks to various places that
were optimising subregs or extractions in ways that only made sense
for scalar integers.  Often the subreg transformations were looking
for extends, truncates or shifts and trying to remove the subreg, which
wouldn't be correct if the SUBREG_REG was a vector rather than a scalar.

The simplify_binary_operation_1 part also removes a redundant:

  GET_MODE (opleft) == GET_MODE (XEXP (opright, 0))

since this must be true for:

  (ior A (lshifrt B ...))  A == opleft, B == XEXP (opright, 0)

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

gcc/
	* combine.c (find_split_point): Add is_a <scalar_int_mode> checks.
	(make_compound_operation_int): Likewise.
	(change_zero_ext): Likewise.
	* expr.c (convert_move): Likewise.
	(convert_modes): Likewise.
	* fwprop.c (forward_propagate_subreg): Likewise.
	* loop-iv.c (get_biv_step_1): Likewise.
	* optabs.c (widen_operand): Likewise.
	* postreload.c (move2add_valid_value_p): Likewise.
	* recog.c (simplify_while_replacing): Likewise.
	* simplify-rtx.c (simplify_unary_operation_1): Likewise.
	(simplify_binary_operation_1): Likewise.  Remove redundant
	mode equality check.

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

From-SVN: r251478

Explicitly check for scalar_int_mode in code that maps arithmetic
to full-mode bit operations.  These operations wouldn't work correctly
for vector modes, for example.  In many cases this is enforced also by
checking whether an operand is CONST_INT_P, but there were other cases
where the condition is more indirect.

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

gcc/
	* combine.c (combine_simplify_rtx): Add checks for
	is_a <scalar_int_mode>.
	(simplify_if_then_else): Likewise.
	(make_field_assignment): Likewise.
	(simplify_comparison): Likewise.
	* ifcvt.c (noce_try_bitop): Likewise.
	* loop-invariant.c (canonicalize_address_mult): Likewise.
	* simplify-rtx.c (simplify_unary_operation_1): Likewise.

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

From-SVN: r251477