diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa_pre_codegen.erl')
| -rw-r--r-- | lib/compiler/src/beam_ssa_pre_codegen.erl | 108 |
1 files changed, 89 insertions, 19 deletions
diff --git a/lib/compiler/src/beam_ssa_pre_codegen.erl b/lib/compiler/src/beam_ssa_pre_codegen.erl index 36137ef046..9175931375 100644 --- a/lib/compiler/src/beam_ssa_pre_codegen.erl +++ b/lib/compiler/src/beam_ssa_pre_codegen.erl @@ -131,6 +131,10 @@ passes(Opts) -> ?PASS(find_yregs), ?PASS(reserve_yregs), + %% Handle legacy binary match instruction that don't + %% accept a Y register as destination. + ?PASS(legacy_bs), + %% Improve reuse of Y registers to potentially %% reduce the size of the stack frame. ?PASS(copy_retval), @@ -612,6 +616,59 @@ bs_subst_ctx(#b_var{}=Var, CtxChain) -> bs_subst_ctx(Other, _CtxChain) -> Other. +%% legacy_bs(St0) -> St. +%% Binary matching instructions in OTP 21 and earlier don't support +%% a Y register as destination. If St#st.use_bsm3 is false, +%% we will need to rewrite those instructions so that the result +%% is first put in an X register and then moved to a Y register +%% if the operation succeeded. + +legacy_bs(#st{use_bsm3=false,ssa=Blocks0,cnt=Count0,res=Res}=St) -> + IsYreg = maps:from_list([{V,true} || {V,{y,_}} <- Res]), + Linear0 = beam_ssa:linearize(Blocks0), + {Linear,Count} = legacy_bs(Linear0, IsYreg, Count0, #{}, []), + Blocks = maps:from_list(Linear), + St#st{ssa=Blocks,cnt=Count}; +legacy_bs(#st{use_bsm3=true}=St) -> St. + +legacy_bs([{L,Blk}|Bs], IsYreg, Count0, Copies0, Acc) -> + #b_blk{is=Is0,last=Last} = Blk, + Is1 = case Copies0 of + #{L:=Copy} -> [Copy|Is0]; + #{} -> Is0 + end, + {Is,Count,Copies} = legacy_bs_is(Is1, Last, IsYreg, Count0, Copies0, []), + legacy_bs(Bs, IsYreg, Count, Copies, [{L,Blk#b_blk{is=Is}}|Acc]); +legacy_bs([], _IsYreg, Count, _Copies, Acc) -> + {Acc,Count}. + +legacy_bs_is([#b_set{op=Op,dst=Dst}=I0, + #b_set{op=succeeded,dst=SuccDst,args=[Dst]}=SuccI0], + Last, IsYreg, Count0, Copies0, Acc) -> + NeedsFix = is_map_key(Dst, IsYreg) andalso + case Op of + bs_get -> true; + bs_init -> true; + _ -> false + end, + case NeedsFix of + true -> + TempDst = #b_var{name={'@bs_temp_dst',Count0}}, + Count = Count0 + 1, + I = I0#b_set{dst=TempDst}, + SuccI = SuccI0#b_set{args=[TempDst]}, + Copy = #b_set{op=copy,dst=Dst,args=[TempDst]}, + #b_br{bool=SuccDst,succ=SuccL} = Last, + Copies = Copies0#{SuccL=>Copy}, + legacy_bs_is([], Last, IsYreg, Count, Copies, [SuccI,I|Acc]); + false -> + legacy_bs_is([], Last, IsYreg, Count0, Copies0, [SuccI0,I0|Acc]) + end; +legacy_bs_is([I|Is], Last, IsYreg, Count, Copies, Acc) -> + legacy_bs_is(Is, Last, IsYreg, Count, Copies, [I|Acc]); +legacy_bs_is([], _Last, _IsYreg, Count, Copies, Acc) -> + {reverse(Acc),Count,Copies}. + %% sanitize(St0) -> St. %% Remove constructs that can cause problems later: %% @@ -652,21 +709,24 @@ sanitize([], Count, Blocks0, Values) -> false -> remove_unreachable(Ls, Blocks, Reachable, []) end,Count}. -sanitize_is([#b_set{op=get_map_element, - args=[#b_literal{}=Map,Key]}=I0|Is], - Count0, Values, _Changed, Acc) -> - {MapVar,Count} = new_var('@ssa_map', Count0), - I = I0#b_set{args=[MapVar,Key]}, - Copy = #b_set{op=copy,dst=MapVar,args=[Map]}, - sanitize_is(Is, Count, Values, true, [I,Copy|Acc]); +sanitize_is([#b_set{op=get_map_element,args=Args0}=I0|Is], + Count0, Values, Changed, Acc) -> + case sanitize_args(Args0, Values) of + [#b_literal{}=Map,Key] -> + %% Bind the literal map to a variable. + {MapVar,Count} = new_var('@ssa_map', Count0), + I = I0#b_set{args=[MapVar,Key]}, + Copy = #b_set{op=copy,dst=MapVar,args=[Map]}, + sanitize_is(Is, Count, Values, true, [I,Copy|Acc]); + [_,_]=Args0 -> + sanitize_is(Is, Count0, Values, Changed, [I0|Acc]); + [_,_]=Args -> + I = I0#b_set{args=Args}, + sanitize_is(Is, Count0, Values, Changed, [I|Acc]) + end; sanitize_is([#b_set{op=Op,dst=Dst,args=Args0}=I0|Is0], - Count, Values, Changed, Acc) -> - Args = map(fun(Var) -> - case Values of - #{Var:=New} -> New; - #{} -> Var - end - end, Args0), + Count, Values, Changed0, Acc) -> + Args = sanitize_args(Args0, Values), case sanitize_instr(Op, Args, I0) of {value,Value0} -> Value = #b_literal{val=Value0}, @@ -674,7 +734,9 @@ sanitize_is([#b_set{op=Op,dst=Dst,args=Args0}=I0|Is0], {ok,I} -> sanitize_is(Is0, Count, Values, true, [I|Acc]); ok -> - sanitize_is(Is0, Count, Values, Changed, [I0|Acc]) + I = I0#b_set{args=Args}, + Changed = Changed0 orelse Args =/= Args0, + sanitize_is(Is0, Count, Values, Changed, [I|Acc]) end; sanitize_is([], Count, Values, Changed, Acc) -> case Changed of @@ -684,6 +746,14 @@ sanitize_is([], Count, Values, Changed, Acc) -> no_change end. +sanitize_args(Args, Values) -> + map(fun(Var) -> + case Values of + #{Var:=New} -> New; + #{} -> Var + end + end, Args). + sanitize_instr({bif,Bif}, [#b_literal{val=Lit}], _I) -> case erl_bifs:is_pure(erlang, Bif, 1) of false -> @@ -973,11 +1043,11 @@ need_frame_1([#b_set{op=call,args=[Func|_]}|Is], Context) -> #b_remote{} -> %% This is an apply(), which always needs a frame. true; - #b_var{} -> - %% A fun call always needs a frame. - true; + #b_local{} -> + Context =:= body orelse Is =/= []; _ -> - Context =:= body orelse Is =/= [] + %% A fun call always needs a frame. + true end; need_frame_1([I|Is], Context) -> beam_ssa:clobbers_xregs(I) orelse need_frame_1(Is, Context); |