%% -*- erlang-indent-level: 2 -*-
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
-module(hipe_arm_registers).
-export([reg_name_gpr/1,
first_virtual/0,
is_precoloured_gpr/1,
all_precoloured/0, % for coalescing
return_value/0,
temp1/0, % C callee-save, not parameter, may be allocatable
temp2/0, % not parameter, must not be allocatable (frame)
temp3/0, % not parameter, may be allocatable
heap_pointer/0,
stack_pointer/0,
proc_pointer/0,
lr/0,
pc/0,
%% heap_limit/0,
%% fcalls/0,
allocatable_gpr/0, % for coalescing
is_fixed/1, % for graph coloring
nr_args/0,
arg/1,
args/1,
is_arg/1, % for linear scan
call_clobbered/0,
tailcall_clobbered/0,
live_at_return/0
]).
-include("../rtl/hipe_literals.hrl").
-define(R0, 0).
-define(R1, 1).
-define(R2, 2).
-define(R3, 3).
-define(R4, 4).
-define(R5, 5).
-define(R6, 6).
-define(R7, 7).
-define(R8, 8).
-define(R9, 9).
-define(R10, 10).
-define(R11, 11).
-define(R12, 12).
-define(R13, 13). % XXX: see all_precoloured()
-define(R14, 14).
-define(R15, 15).
-define(LAST_PRECOLOURED, 15). % must handle both GPR and FPR ranges
-define(LR, ?R14).
-define(ARG0, ?R1).
-define(ARG1, ?R2).
-define(ARG2, ?R3).
-define(ARG3, ?R4).
-define(ARG4, ?R5).
-define(ARG5, ?R6).
-define(TEMP1, ?R8). % stores LR around inc_stack calls, must be C calleE-save
-define(TEMP2, ?R12).
-define(TEMP3, ?R7).
-define(RETURN_VALUE, ?R0).
-define(HEAP_POINTER, ?R9).
-define(STACK_POINTER, ?R10).
-define(PROC_POINTER, ?R11).
reg_name_gpr(R) -> [$r | integer_to_list(R)].
%%% Must handle both GPR and FPR ranges.
first_virtual() -> ?LAST_PRECOLOURED + 1.
%%% These two tests have the same implementation, but that's
%%% not something we should cast in stone in the interface.
is_precoloured_gpr(R) -> R =< ?LAST_PRECOLOURED.
all_precoloured() ->
%% XXX: R13 should be skipped as it never is used anywhere.
%% Unfortunately, gaps in the list of precoloured registers
%% cause the graph_color register allocator to create bogus
%% assignments for those "registers", which in turn causes
%% the "precoloured reg must map to itself" sanity check in
%% the frame module to signal errors.
[ ?R0, ?R1, ?R2, ?R3, ?R4, ?R5, ?R6, ?R7,
?R8, ?R9, ?R10, ?R11, ?R12, ?R13, ?R14, ?R15].
return_value() -> ?RETURN_VALUE.
temp1() -> ?TEMP1.
temp2() -> ?TEMP2.
temp3() -> ?TEMP3. % for base2 in storeix :-(
heap_pointer() -> ?HEAP_POINTER.
stack_pointer() -> ?STACK_POINTER.
proc_pointer() -> ?PROC_POINTER.
lr() -> ?LR.
pc() -> ?R15.
allocatable_gpr() ->
%% r9, r10, and r11 are fixed global registers.
%% r12 may be used by the frame module for large load/store offsets.
%% r13 is reserved for C.
%% r15 is the PC, and is not usable as a variable.
[ ?R0, ?R1, ?R2, ?R3, ?R4, ?R5, ?R6, ?R7,
?R8, ?R14].
%% Needed for hipe_graph_coloring_regalloc.
%% Presumably true for Reg in AllPrecoloured \ Allocatable.
is_fixed(Reg) ->
case Reg of
?HEAP_POINTER -> true;
?STACK_POINTER -> true;
?PROC_POINTER -> true;
%% The following cases are required for linear scan:
%% it gets confused if it sees a register which is
%% neither allocatable nor global (fixed or one of
%% the scratch registers set aside for linear scan).
?R15 -> true;
?R13 -> true; % XXX: see all_precoloured()
?R12 -> true;
_ -> false
end.
nr_args() -> ?ARM_NR_ARG_REGS.
args(Arity) when is_integer(Arity) ->
N = erlang:min(Arity, ?ARM_NR_ARG_REGS),
args(N-1, []).
args(-1, Rest) -> Rest;
args(I, Rest) -> args(I-1, [arg(I) | Rest]).
arg(N) ->
if N < ?ARM_NR_ARG_REGS ->
case N of
0 -> ?ARG0;
1 -> ?ARG1;
2 -> ?ARG2;
3 -> ?ARG3;
4 -> ?ARG4;
5 -> ?ARG5;
_ -> exit({?MODULE, arg, N})
end;
true ->
exit({?MODULE, arg, N})
end.
is_arg(R) ->
case R of
?ARG0 -> ?ARM_NR_ARG_REGS > 0;
?ARG1 -> ?ARM_NR_ARG_REGS > 1;
?ARG2 -> ?ARM_NR_ARG_REGS > 2;
?ARG3 -> ?ARM_NR_ARG_REGS > 3;
?ARG4 -> ?ARM_NR_ARG_REGS > 4;
?ARG5 -> ?ARM_NR_ARG_REGS > 5;
_ -> false
end.
%% Note: the fact that allocatable_gpr() is a subset of call_clobbered() is
%% hard-coded in hipe_arm_defuse:insn_defs_all_gpr/1
call_clobbered() -> % does the RA strip the type or not?
[{?R0,tagged},{?R0,untagged},
{?R1,tagged},{?R1,untagged},
{?R2,tagged},{?R2,untagged},
{?R3,tagged},{?R3,untagged},
{?R4,tagged},{?R4,untagged},
{?R5,tagged},{?R5,untagged},
{?R6,tagged},{?R6,untagged},
{?R7,tagged},{?R7,untagged},
{?R8,tagged},{?R8,untagged},
%% R9 is fixed (HP)
%% R10 is fixed (NSP)
%% R11 is fixed (P)
{?R12,tagged},{?R12,untagged},
%% R13 is reserved for C
{?R14,tagged},{?R14,untagged}
%% R15 is the non-allocatable PC
].
tailcall_clobbered() -> % tailcall crapola needs one temp
[{?TEMP1,tagged},{?TEMP1,untagged}
,{?LR,tagged},{?LR,untagged}
].
live_at_return() ->
[%%{?LR,untagged},
{?HEAP_POINTER,untagged},
{?STACK_POINTER,untagged},
{?PROC_POINTER,untagged}
].
