RFA: always supply a mode to plus_constant

[Richard Sandiford <rdsandiford at googlemail dot com>]

As mentioned in the discussion of Mike's >2HWI patch, plus_constant is
AFAIK the only rtl routine that handles arithmetic on CONST_INT without
specifying the mode of the CONST_INT.  That means it isn't always able
to generate the right result.  E.g. it returns 0x80 for a QImode add of
0x7f and 0x1, whereas the correct result is 0xff....ff80.

Mike's patch therefore introduced plus_constant_mode.  This allowed
the routine to call itself recursively for CONST_INTs embedded in PLUSes,
rather than having to treat them as a special case.

This patch fixes the FIXME introduced in that patch: that all callers
really ought to specify the mode.  It's true that many callers are known
to pass a register, but rather than try to justify on a case-by-case
basis why a mode doesn't need to be passed, it seems better to always
pass one.  Most other rtl routines (e.g. the simplify_* ones) work in
just the same way.

One way of doing this would have been to semd patches that make
individual files use plus_constant_mode.  Then, once all the calls had
been converted, and nothing called plus_constant, we could mechanically
rename plus_constant_mode to plus_constant (because the _mode would be
redundant, and inconsistent with things like the simplify routines).
But that would mean a lot of SVN churn.  Many calls to plus_constant are
pressed up against the right side of the screen, and would need to be
reformatted for the longer name.  Then the mechanical rename would have
to reformat them again, in many cases going back to the original.

So I think the best way is simply to do the whole thing as one patch.
Which means it needs a GWP...

I did actually develop the patch by renaming the function (so that grep
would tell me if I'd caught all calls) then renaming it back.  If there
are strong objections to doing it in one step, I can go back to that.

Bootstrapped & regression-tested on x86_64-linux-gnu.  Also tested by
compiling gcc for the following targets and making sure that the output
of the gcc.c-torture and gcc.dg testsuites were the same at -O3 -g:

	alpha-linux-gnu arm-linux-gnueabi avr-rtems bfin-elf c6x-elf
	cr16-elf cris-elf epiphany-elf fr30-elf frv-linux-gnu h8300-elf
	ia64-linux-gnu iq2000-elf lm32-elf m32c-elf m32r-elf
	m68k-linux-gnu mcore-elf mep-elf microblaze-elf mips-linux-gnu
	mmix mn10300-elf moxie-elf hppa64-hp-hpux11.23 pdp11
	picochip-elf powerpc-linux-gnu powerpc-eabispe rl78-elf rx-elf
	s390-linux-gnu score-elf sh-linux-gnu sparc-linux-gnu spu-elf
	tilegx-elf tilepro-elf xstormy16-elf v850-elf vax-netbsdelf
	xtensa-elf

OK to install?

Richard


gcc/
	* rtl.h (plus_constant, plus_constant_mode): Merge into a single
	plus_constant function.
	* explow.c (plus_constant, plus_constant_mode): Likewise.  Assert
	that the mode is sensible.
	(use_anchored_address, round_push, allocate_dynamic_stack_space)
	(probe_stack_range, anti_adjust_stack_and_probe): Update calls to
	plus_constant.

	* alias.c (canon_rtx): Likewise.
	(init_alias_analysis): Likewise.
	* builtins.c (expand_builtin_return_addr)
	(expand_builtin_setjmp_setup, expand_builtin_longjmp)
	(expand_builtin_nonlocal_goto, expand_builtin_update_setjmp_buf)
	(expand_builtin_apply_args_1, expand_builtin_apply, expand_movstr)
	(expand_builtin_stpcpy): Likewise.
	* calls.c (save_fixed_argument_area, restore_fixed_argument_area)
	(compute_argument_addresses, internal_arg_pointer_based_exp)
	(expand_call, emit_library_call_value_1): Likewise.
	* cfgexpand.c (expand_one_stack_var_at, expand_debug_expr): Likewise.
	* combine-stack-adj.c (try_apply_stack_adjustment): Likewise.
	* combine.c (combine_simplify_rtx, force_to_mode): Likewise.
	* cse.c (insert_const_anchor, find_reg_offset_for_const)
	(use_related_value, fold_rtx): Likewise.
	* cselib.c (cselib_subst_to_values): Likewise.
	* dse.c (record_store, check_mem_read_rtx): Likewise.
	* dwarf2out.c (rtl_for_decl_location, gen_variable_die): Likewise.
	* emit-rtl.c (adjust_address_1): Likewise.
	* except.c (sjlj_emit_function_enter)
	(expand_builtin_extract_return_addr)
	(expand_builtin_frob_return_addr): Likewise.
	* expmed.c (expand_divmod): Likewise.
	* expr.c (move_by_pieces, store_by_pieces, store_by_pieces_1)
	(emit_move_resolve_push, push_block, emit_push_insn, store_expr)
	(expand_expr_addr_expr_1, expand_expr_real_1): Likewise.
	* function.c (assign_stack_local_1)
	(instantiate_virtual_regs_in_rtx): Likewise.
	* optabs.c (prepare_cmp_insn): Likewise.
	* recog.c (offsettable_address_addr_space_p): Likewise.
	* reload.c (find_reloads_address, form_sum)
	(find_reloads_subreg_address): Likewise.
	* reload1.c (init_reload, eliminate_regs_1)
	(eliminate_regs_in_insn): Likewise.
	* simplify-rtx.c (simplify_unary_operation_1)
	(simplify_binary_operation_1, simplify_plus_minus): Likewise.
	* var-tracking.c (compute_cfa_pointer, prepare_call_arguments)
	(vt_add_function_parameter): Likewise.

	* config/alpha/alpha.h (EH_RETURN_HANDLER_RTX): Likewise.
	* config/alpha/vms.h (EH_RETURN_HANDLER_RTX): Likewise.
	* config/alpha/alpha.c (alpha_legitimize_address_1)
	(get_unaligned_address, alpha_expand_unaligned_load)
	(alpha_expand_unaligned_store, alpha_expand_unaligned_load_words)
	(alpha_expand_unaligned_store_words, alpha_expand_block_clear)
	(alpha_expand_builtin_establish_vms_condition_handler)
	(alpha_setup_incoming_varargs, emit_frame_store_1)
	(alpha_expand_prologue, alpha_expand_epilogue)
	(alpha_use_linkage): Likewise.
	* config/alpha/alpha.md: Likewise.

	* config/arm/arm.c (arm_trampoline_init, legitimize_pic_address)
	(arm_load_pic_register, arm_pic_static_addr, arm_legitimize_address)
	(thumb_legitimize_address, arm_gen_load_multiple_1)
	(arm_gen_store_multiple_1, arm_gen_multiple_op, gen_ldm_seq)
	(gen_stm_seq, gen_const_stm_seq, arm_block_move_unaligned_straight)
	(arm_block_move_unaligned_loop, arm_gen_movmemqi, arm_reload_in_hi)
	(arm_reload_out_hi, arm_reorg, vfp_emit_fstmd, emit_multi_reg_push)
	(emit_sfm, thumb_set_frame_pointer, arm_expand_prologue)
	(thumb1_emit_multi_reg_push, thumb1_expand_prologue)
	(thumb_expand_movmemqi, arm_set_return_address)
	(thumb_set_return_address): Likewise.
	* config/arm/arm.md: Likewise.

	* config/avr/avr.c (avr_incoming_return_addr_rtx)
	(avr_prologue_setup_frame, expand_epilogue)
	(avr_const_address_lo16): Likewise.

	* config/bfin/bfin.h (EH_RETURN_HANDLER_RTX): Likewise.
	* config/bfin/bfin.c (setup_incoming_varargs, bfin_load_pic_reg)
	(bfin_expand_prologue, bfin_trampoline_init, bfin_expand_call)
	(bfin_output_mi_thunk): Likewise.

	* config/c6x/c6x.c (c6x_initialize_trampoline)
	(c6x_output_mi_thunk): Likewise.

	* config/cr16/cr16.h (EH_RETURN_HANDLER_RTX): Likewise.
	* config/cr16/cr16.c (cr16_create_dwarf_for_multi_push): Likewise.

	* config/cris/cris.c (cris_return_addr_rtx, cris_split_movdx)
	(cris_expand_prologue, cris_expand_epilogue, cris_gen_movem_load)
	(cris_emit_movem_store, cris_trampoline_init): Likewise.
	* config/cris/cris.md: Likewise.

	* config/darwin.c (machopic_indirect_data_reference)
	(machopic_legitimize_pic_address): Likewise.

	* config/epiphany/epiphany.c (epiphany_emit_save_restore)
	(epiphany_expand_prologue, epiphany_expand_epilogue)
	(epiphany_trampoline_init): Likewise.
	* config/epiphany/epiphany.md: Likewise.

	* config/fr30/fr30.c (fr30_move_double): Likewise.

	* config/frv/frv.c (frv_dwarf_store, frv_expand_prologue)
	(frv_expand_block_move, frv_expand_block_clear, frv_return_addr_rtx)
	(frv_index_memory, unspec_got_name, frv_find_base_term)
	(frv_output_dwarf_dtprel): Likewise.

	* config/h8300/h8300.c (h8300_push_pop, h8300_return_addr_rtx)
	(h8300_swap_into_er6, h8300_swap_out_of_er6): Likewise.

	* config/i386/i386.h (RETURN_ADDR_RTX): Likewise.
	* config/i386/i386.c (setup_incoming_varargs_64)
	(setup_incoming_varargs_ms_64, choose_baseaddr)
	(ix86_emit_save_reg_using_mov, ix86_adjust_stack_and_probe)
	(ix86_emit_probe_stack_range, ix86_expand_prologue)
	(ix86_emit_restore_reg_using_pop, ix86_emit_leave)
	(ix86_expand_epilogue, legitimize_pic_address, ix86_legitimize_address)
	(ix86_split_long_move, ix86_expand_movmem, ix86_expand_setmem)
	(ix86_static_chain, ix86_trampoline_init, x86_this_parameter)
	(x86_output_mi_thunk): Likewise.
	* config/i386/i386.md: Likewise.

	* config/ia64/ia64.c (ia64_expand_load_address)
	(ia64_expand_tls_address, ia64_expand_move, ia64_split_tmode)
	(do_spill, ia64_trampoline_init): Likewise.

	* config/iq2000/iq2000.c (iq2000_va_start)
	(iq2000_emit_frame_related_store, iq2000_expand_prologue)
	(iq2000_expand_eh_return, iq2000_setup_incoming_varargs)
	(iq2000_print_operand, iq2000_legitimize_address): Likewise.

	* config/lm32/lm32.c (lm32_setup_incoming_varargs): Likewise.

	* config/m32c/m32c.c (m32c_return_addr_rtx)
	(m32c_expand_insv): Likewise.

	* config/m32r/m32r.c (m32r_setup_incoming_varargs)
	(m32r_legitimize_pic_address, m32r_print_operand)
	(m32r_print_operand_address): Likewise.

	* config/m68k/linux.h (FINALIZE_TRAMPOLINE): Likewise.
	* config/m68k/m68k.h (RETURN_ADDR_RTX): Likewise.
	(EH_RETURN_HANDLER_RTX): Likewise.
	* config/m68k/m68k.c (m68k_emit_movem, m68k_expand_prologue)
	(m68k_expand_epilogue, legitimize_pic_address)
	(m68k_output_mi_thunk): Likewise.
	* config/m68k/m68k.md: Likewise.

	* config/mcore/mcore.c (mcore_expand_prolog): Likewise.
	(mcore_expand_epilog): Likewise.
	* config/mcore/mcore.md: Likewise.

	* config/mep/mep.c (mep_allocate_initial_value)
	(mep_expand_prologue, mep_expand_epilogue): Likewise.

	* config/microblaze/microblaze.c (double_memory_operand)
	(microblaze_block_move_loop): Likewise.

	* config/mips/mips.c (mips_strip_unspec_address, mips_add_offset)
	(mips_setup_incoming_varargs, mips_va_start, mips_block_move_loop)
	(mips_print_operand, mips16e_save_restore_reg, mips_save_restore_reg)
	(mips_expand_prologue, mips_epilogue_set_cfa)
	(mips_expand_epilogue): Likewise.
	* config/mips/mips.md: Likewise.

	* config/mmix/mmix.c (mmix_dynamic_chain_address, mmix_return_addr_rtx)
	(mmix_expand_prologue, mmix_expand_epilogue): Likewise.

	* config/mn10300/mn10300.c (mn10300_gen_multiple_store)
	(mn10300_builtin_saveregs, mn10300_trampoline_init): Likewise.

	* config/moxie/moxie.h (INCOMING_RETURN_ADDR_RTX): Likewise.
	(EH_RETURN_HANDLER_RTX): Likewise.
	* config/moxie/moxie.c (moxie_static_chain): Likewise.

	* config/pa/pa.c (legitimize_pic_address, hppa_legitimize_address)
	(store_reg, set_reg_plus_d, pa_expand_prologue, load_reg)
	(pa_return_addr_rtx, hppa_builtin_saveregs)
	(pa_trampoline_init): Likewise.
	* config/pa/pa.md: Likewise.

	* config/pdp11/pdp11.c (pdp11_expand_epilogue): Likewise.

	* config/picochip/picochip.c (picochip_static_chain): Likewise.

	* config/rs6000/rs6000.h (RS6000_SAVE_TOC): Likewise.
	* config/rs6000/rs6000.c (rs6000_legitimize_address)
	(setup_incoming_varargs, print_operand, rs6000_return_addr)
	(rs6000_emit_eh_reg_restore, rs6000_emit_probe_stack_range)
	(rs6000_emit_epilogue)
	(rs6000_machopic_legitimize_pic_address): Likewise.

	* config/rx/rx.c (gen_rx_rtsd_vector, gen_rx_popm_vector): Likewise.

	* config/s390/s390.h (INITIAL_FRAME_ADDRESS_RTX): Likewise.
	(DYNAMIC_CHAIN_ADDRESS): Likewise.
	* config/s390/s390.c (s390_decompose_address, legitimize_pic_address)
	(s390_delegitimize_address, print_operand, annotate_constant_pool_refs)
	(replace_constant_pool_ref, s390_return_addr_rtx, s390_back_chain_rtx)
	(save_fpr, restore_fpr, save_gprs, restore_gprs, s390_emit_prologue)
	(s390_emit_epilogue, s390_function_profiler): Likewise.
	* config/s390/s390.md: Likewise.

	* config/score/score.c (score_add_offset, score_prologue): Likewise.

	* config/sh/sh.c (expand_block_move, push_regs, sh_builtin_saveregs)
	(sh_output_mi_thunk): Likewise.
	* config/sh/sh.md: Likewise.

	* config/sparc/sparc.h (DYNAMIC_CHAIN_ADDRESS, FRAME_ADDR_RTX)
	(RETURN_ADDR_RTX, INCOMING_RETURN_ADDR_RTX): Likewise.
	* config/sparc/sparc.c (sparc_legitimize_pic_address)
	(sparc_emit_probe_stack_range, emit_save_or_restore_regs)
	(emit_window_save, sparc_flat_expand_prologue, sparc_struct_value_rtx)
	(emit_and_preserve): Likewise.
	* config/sparc/sparc.md: Likewise.

	* config/spu/spu.h (DYNAMIC_CHAIN_ADDRESS): Likewise.
	* config/spu/spu.c (spu_expand_insv, spu_machine_dependent_reorg)
	(spu_setup_incoming_varargs, ea_load_store_inline)
	(spu_expand_load): Likewise.

	* config/stormy16/stormy16.c (xstormy16_expand_prologue)
	(combine_bnp): Likewise.

	* config/tilegx/tilegx.h (DYNAMIC_CHAIN_ADDRESS): Likewise.
	* config/tilegx/tilegx.c (tilegx_setup_incoming_varargs)
	(tilegx_expand_unaligned_load, tilegx_trampoline_init): Likewise.

	* config/tilepro/tilepro.h (DYNAMIC_CHAIN_ADDRESS): Likewise.
	* config/tilepro/tilepro.c (tilepro_setup_incoming_varargs)
	(tilepro_expand_unaligned_load, tilepro_trampoline_init): Likewise.

	* config/v850/v850.c (expand_prologue, expand_epilogue): Likewise.
	* config/v850/v850.md: Likewise.

	* config/vax/elf.h (EH_RETURN_STACKADJ_RTX): Likewise.
	(EH_RETURN_HANDLER_RTX): Likewise.
	* config/vax/vax.h (DYNAMIC_CHAIN_ADDRESS, RETURN_ADDR_RTX): Likewise.
	* config/vax/vax.c (vax_add_reg_cfa_offset, vax_expand_prologue)
	(print_operand_address, vax_trampoline_init): Likewise.

	* config/xtensa/xtensa.c (xtensa_expand_prologue, xtensa_return_addr)
	(xtensa_function_value_regno_p): Likewise.

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