diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa_pre_codegen.erl')
| -rw-r--r-- | lib/compiler/src/beam_ssa_pre_codegen.erl | 116 |
1 files changed, 114 insertions, 2 deletions
diff --git a/lib/compiler/src/beam_ssa_pre_codegen.erl b/lib/compiler/src/beam_ssa_pre_codegen.erl index bf99e8fc26..878493e926 100644 --- a/lib/compiler/src/beam_ssa_pre_codegen.erl +++ b/lib/compiler/src/beam_ssa_pre_codegen.erl @@ -108,7 +108,8 @@ functions([], _Ps, _UseBSM3) -> []. intervals=[] :: [{b_var(),[range()]}], res=[] :: [{b_var(),reservation()}] | #{b_var():=reservation()}, regs=#{} :: #{b_var():=ssa_register()}, - extra_annos=[] :: [{atom(),term()}] + extra_annos=[] :: [{atom(),term()}], + location :: term() }). -define(PASS(N), {N,fun N/1}). @@ -120,6 +121,7 @@ passes(Opts) -> %% Preliminaries. ?PASS(fix_bs), ?PASS(sanitize), + ?PASS(match_fail_instructions), case FixTuples of false -> ignore; true -> ?PASS(fix_tuples) @@ -162,7 +164,9 @@ passes(Opts) -> function(#b_function{anno=Anno,args=Args,bs=Blocks0,cnt=Count0}=F0, Ps, UseBSM3) -> try - St0 = #st{ssa=Blocks0,args=Args,use_bsm3=UseBSM3,cnt=Count0}, + Location = maps:get(location, Anno, none), + St0 = #st{ssa=Blocks0,args=Args,use_bsm3=UseBSM3, + cnt=Count0,location=Location}, St = compile:run_sub_passes(Ps, St0), #st{ssa=Blocks,cnt=Count,regs=Regs,extra_annos=ExtraAnnos} = St, F1 = add_extra_annos(F0, ExtraAnnos), @@ -854,6 +858,114 @@ prune_phi(#b_set{args=Args0}=Phi, Reachable) -> gb_sets:is_element(Pred, Reachable)], Phi#b_set{args=Args}. +%%% Rewrite certain calls to erlang:error/{1,2} to specialized +%%% instructions: +%%% +%%% erlang:error({badmatch,Value}) => badmatch Value +%%% erlang:error({case_clause,Value}) => case_end Value +%%% erlang:error({try_clause,Value}) => try_case_end Value +%%% erlang:error(if_clause) => if_end +%%% erlang:error(function_clause, Args) => jump FuncInfoLabel +%%% +%%% In SSA code, we represent those instructions as a 'match_fail' +%%% instruction with the name of the BEAM instruction as the first +%%% argument. + +match_fail_instructions(#st{ssa=Blocks0,args=Args,location=Location}=St) -> + Ls = maps:to_list(Blocks0), + Info = {length(Args),Location}, + Blocks = match_fail_instrs_1(Ls, Info, Blocks0), + St#st{ssa=Blocks}. + +match_fail_instrs_1([{L,#b_blk{is=Is0}=Blk}|Bs], Arity, Blocks0) -> + case match_fail_instrs_blk(Is0, Arity, []) of + none -> + match_fail_instrs_1(Bs, Arity, Blocks0); + Is -> + Blocks = Blocks0#{L:=Blk#b_blk{is=Is}}, + match_fail_instrs_1(Bs, Arity, Blocks) + end; +match_fail_instrs_1([], _Arity, Blocks) -> Blocks. + +match_fail_instrs_blk([#b_set{op=put_tuple,dst=Dst, + args=[#b_literal{val=Tag},Val]}, + #b_set{op=call, + args=[#b_remote{mod=#b_literal{val=erlang}, + name=#b_literal{val=error}}, + Dst]}=Call|Is], + _Arity, Acc) -> + match_fail_instr(Call, Tag, Val, Is, Acc); +match_fail_instrs_blk([#b_set{op=call, + args=[#b_remote{mod=#b_literal{val=erlang}, + name=#b_literal{val=error}}, + #b_literal{val={Tag,Val}}]}=Call|Is], + _Arity, Acc) -> + match_fail_instr(Call, Tag, #b_literal{val=Val}, Is, Acc); +match_fail_instrs_blk([#b_set{op=call, + args=[#b_remote{mod=#b_literal{val=erlang}, + name=#b_literal{val=error}}, + #b_literal{val=if_clause}]}=Call|Is], + _Arity, Acc) -> + I = Call#b_set{op=match_fail,args=[#b_literal{val=if_end}]}, + reverse(Acc, [I|Is]); +match_fail_instrs_blk([#b_set{op=call,anno=Anno, + args=[#b_remote{mod=#b_literal{val=erlang}, + name=#b_literal{val=error}}, + #b_literal{val=function_clause}, + Stk]}=Call], + {Arity,Location}, Acc) -> + case match_fail_stk(Stk, Acc, [], []) of + {[_|_]=Vars,Is} when length(Vars) =:= Arity -> + case maps:get(location, Anno, none) of + Location -> + I = Call#b_set{op=match_fail, + args=[#b_literal{val=function_clause}|Vars]}, + Is ++ [I]; + _ -> + %% erlang:error/2 has a different location than the + %% func_info instruction at the beginning of the function + %% (probably because of inlining). Keep the original call. + reverse(Acc, [Call]) + end; + _ -> + %% Either the stacktrace could not be picked apart (for example, + %% if the call to erlang:error/2 was handwritten) or the number + %% of arguments in the stacktrace was different from the arity + %% of the host function (because it is the implementation of a + %% fun). Keep the original call. + reverse(Acc, [Call]) + end; +match_fail_instrs_blk([I|Is], Arity, Acc) -> + match_fail_instrs_blk(Is, Arity, [I|Acc]); +match_fail_instrs_blk(_, _, _) -> + none. + +match_fail_instr(Call, Tag, Val, Is, Acc) -> + Op = case Tag of + badmatch -> Tag; + case_clause -> case_end; + try_clause -> try_case_end; + _ -> none + end, + case Op of + none -> + none; + _ -> + I = Call#b_set{op=match_fail,args=[#b_literal{val=Op},Val]}, + reverse(Acc, [I|Is]) + end. + +match_fail_stk(#b_var{}=V, [#b_set{op=put_list,dst=V,args=[H,T]}|Is], IAcc, VAcc) -> + match_fail_stk(T, Is, IAcc, [H|VAcc]); +match_fail_stk(#b_literal{val=[H|T]}, Is, IAcc, VAcc) -> + match_fail_stk(#b_literal{val=T}, Is, IAcc, [#b_literal{val=H}|VAcc]); +match_fail_stk(#b_literal{val=[]}, [], IAcc, VAcc) -> + {reverse(VAcc),IAcc}; +match_fail_stk(T, [#b_set{op=Op}=I|Is], IAcc, VAcc) + when Op =:= bs_get_tail; Op =:= bs_set_position -> + match_fail_stk(T, Is, [I|IAcc], VAcc); +match_fail_stk(_, _, _, _) -> none. + %%% %%% Fix tuples. %%% |