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sim_core:calculate_ea/5: replace IR parameter with a continuation, to decouple it from dispatch/4

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This commit is contained in:
Mikael Pettersson 2020-10-17 15:45:43 +02:00
parent 997a38e612
commit 0e7ff775f7
1 changed files with 26 additions and 25 deletions
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51
erlang/apps/sim/src/sim_core.erl
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@ -139,12 +139,13 @@ insn_fetch1(Core, Mem) ->
insn_fetch2(Core, Mem, MB) ->
IR = bits36(MB, 0, 12), % IR := MB_<0:12>
ESection = Core#core.pc_section, % E_<6:17> := PC_<6:17>
calculate_ea(Core, Mem, IR, MB, ESection).
calculate_ea(Core, Mem, MB, ESection,
fun(Core1, Mem1, EA) -> dispatch(Core1, Mem1, IR, EA) end).
calculate_ea(Core, Mem, IR, MB, ESection) ->
local_format_address_word(Core, Mem, IR, MB, ESection).
calculate_ea(Core, Mem, MB, ESection, Cont) ->
local_format_address_word(Core, Mem, MB, ESection, Cont).
local_format_address_word(Core, Mem, IR, MB, ESection) ->
local_format_address_word(Core, Mem, MB, ESection, Cont) ->
Y = bits36(MB, 18, 35), % Y_<18:35> := MB_<18:35>
X = bits36(MB, 14, 17), % X := MB_<14:17>
I = bit36(MB, 13), % I := MB_<13>
@ -153,38 +154,38 @@ local_format_address_word(Core, Mem, IR, MB, ESection) ->
0 ->
%% X field =:= 0. No Indexing.
EOffset = Y, % E_<18:35> := Y_<18:35>
indirect_addressing(Core, Mem, IR, I, ESection, EOffset, _IsLocal = true);
indirect_addressing(Core, Mem, I, ESection, EOffset, _IsLocal = true, Cont);
_ ->
%% X field =/= 0. Indexing.
CX = get_ac(Core, X), % C(X) hoisted from following blocks
%% Test Section Number in E_<6:17>.
case ESection of
0 ->
local_index(Core, Mem, IR, I, ESection, CX, Y);
local_index(Core, Mem, I, ESection, CX, Y, Cont);
_ ->
%% Section =/= 0.
%% Test C(X). Global Index when (C(X)_<0> =:= 0) and (C(X)_<6:17> =/= 0).
case bit36(CX, 0) =:= 0 andalso bits36(CX, 6, 17) =/= 0 of
true ->
global_index(Core, Mem, IR, I, CX, Y);
global_index(Core, Mem, I, CX, Y, Cont);
false ->
local_index(Core, Mem, IR, I, ESection, CX, Y)
local_index(Core, Mem, I, ESection, CX, Y, Cont)
end
end
end.
local_index(Core, Mem, IR, I, ESection, CX, Y) ->
local_index(Core, Mem, I, ESection, CX, Y, Cont) ->
EOffset = bits36low18(CX + Y), % E_<18:35> := C(X)_<18:35> + Y_<18:35>
indirect_addressing(Core, Mem, IR, I, ESection, EOffset, _IsLocal = true).
indirect_addressing(Core, Mem, I, ESection, EOffset, _IsLocal = true, Cont).
global_index(Core, Mem, IR, I, CX, Y) ->
global_index(Core, Mem, I, CX, Y, Cont) ->
Y1 = sext18(Y), % Y_<6:17> =:= 7777 * Y_<18>
E = CX + Y1, % E_<6:35> := C(X)_<6:35> + Y_<6:35>
ESection = bits36(E, 6, 17),
EOffset = bits36(E, 18, 35),
indirect_addressing(Core, Mem, IR, I, ESection, EOffset, _IsLocal = false).
indirect_addressing(Core, Mem, I, ESection, EOffset, _IsLocal = false, Cont).
indirect_addressing(Core, Mem, IR, I, ESection, EOffset, IsLocal) ->
indirect_addressing(Core, Mem, I, ESection, EOffset, IsLocal, Cont) ->
%% Test I bit.
case I of
0 ->
@ -194,36 +195,36 @@ indirect_addressing(Core, Mem, IR, I, ESection, EOffset, IsLocal) ->
%% in the last section from which an address word was fetched. This
%% matters for instructions that use E and E+1, and also to determine
%% if an address denotes an accumulator or a memory location.
dispatch(Core, Mem, IR, #ea{section = ESection, offset = EOffset, islocal = IsLocal});
Cont(Core, Mem, #ea{section = ESection, offset = EOffset, islocal = IsLocal});
_ ->
%% I =:= 1.
fetch_indirect_word(Core, Mem, IR, ESection, EOffset, IsLocal)
fetch_indirect_word(Core, Mem, ESection, EOffset, IsLocal, Cont)
end.
fetch_indirect_word(Core, Mem, IR, ESection, EOffset, IsLocal) ->
fetch_indirect_word(Core, Mem, ESection, EOffset, IsLocal, Cont) ->
%% Fetch the Indirect Word.
case c(Core, Mem, ESection, EOffset, IsLocal) of
{ok, MB} ->
%% Non-zero section? Test E_<6:17>.
case ESection of
0 ->
local_format_address_word(Core, Mem, IR, MB, ESection);
local_format_address_word(Core, Mem, MB, ESection, Cont);
_ ->
%% Section =/= 0.
%% Decode Indirect Word MB_<0:1>.
case bits36(MB, 0, 1) of
0 ->
global_indirect_word(Core, Mem, IR, MB, _I = 0);
global_indirect_word(Core, Mem, MB, _I = 0, Cont);
1 ->
global_indirect_word(Core, Mem, IR, MB, _I = 1);
global_indirect_word(Core, Mem, MB, _I = 1, Cont);
2 ->
%% Local Indirect
local_format_address_word(Core, Mem, IR, MB, ESection);
local_format_address_word(Core, Mem, MB, ESection, Cont);
3 ->
EA = #ea{section = ESection, offset = EOffset, islocal = IsLocal},
page_fault(Core, Mem, EA, read, indirect_word,
fun(Core1, Mem1) ->
fetch_indirect_word(Core1, Mem1, IR, ESection, EOffset, IsLocal)
fetch_indirect_word(Core1, Mem1, ESection, EOffset, IsLocal, Cont)
end)
end
end;
@ -231,11 +232,11 @@ fetch_indirect_word(Core, Mem, IR, ESection, EOffset, IsLocal) ->
EA = #ea{section = ESection, offset = EOffset, islocal = IsLocal},
page_fault(Core, Mem, EA, read, Reason,
fun(Core1, Mem1) ->
fetch_indirect_word(Core1, Mem1, IR, ESection, EOffset, IsLocal)
fetch_indirect_word(Core1, Mem1, ESection, EOffset, IsLocal, Cont)
end)
end.
global_indirect_word(Core, Mem, IR, MB, I) ->
global_indirect_word(Core, Mem, MB, I, Cont) ->
Y = bits36(MB, 6, 35), % Y:= MB_<6,35>
X = bits36(MB, 2, 5), % X := MB_<2:5>
%% Indexed Address? Test X field.
@ -244,14 +245,14 @@ global_indirect_word(Core, Mem, IR, MB, I) ->
E = Y, % E_<6:35> := Y_<6:35>
ESection1 = bits36(E, 6, 17),
EOffset1 = bits36(E, 18, 35),
indirect_addressing(Core, Mem, IR, I, ESection1, EOffset1, _IsLocal = false);
indirect_addressing(Core, Mem, I, ESection1, EOffset1, _IsLocal = false, Cont);
_ ->
%% X =/= 0.
CX = get_ac(Core, X),
E = CX + Y, % E_<6:35> := C(X)_<6:35> + Y_<6:35>
ESection1 = bits36(E, 6, 17),
EOffset1 = bits36(E, 18, 35),
indirect_addressing(Core, Mem, IR, I, ESection1, EOffset1, _IsLocal = false)
indirect_addressing(Core, Mem, I, ESection1, EOffset1, _IsLocal = false, Cont)
end.
%% Instruction Dispatch ========================================================