diff options
Diffstat (limited to 'lib/compiler/src/v3_codegen.erl')
| -rw-r--r-- | lib/compiler/src/v3_codegen.erl | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl index f531056591..f5f3c73793 100644 --- a/lib/compiler/src/v3_codegen.erl +++ b/lib/compiler/src/v3_codegen.erl @@ -1089,6 +1089,23 @@ protected_cg(Ts, Rs, _Fail, I, Vdb, Bef, St0) -> %% test_cg(TestName, Args, Fail, I, Vdb, Bef, St) -> {[Ainstr],Aft,St}. %% Generate test instruction. Use explicit fail label here. +test_cg(is_map, [A], Fail, I, Vdb, Bef, St) -> + %% We must avoid creating code like this: + %% + %% move x(0) y(0) + %% is_map Fail [x(0)] + %% make_fun => x(0) %% Overwrite x(0) + %% put_map_assoc y(0) ... + %% + %% The code is safe, but beam_validator does not understand that. + %% Extending beam_validator to handle such (rare) code as the + %% above would make it slower for all programs. Instead, change + %% the code generator to always prefer the Y register for is_map() + %% and put_map_assoc() instructions, ensuring that they use the + %% same register. + Arg = cg_reg_arg_prefer_y(A, Bef), + Aft = clear_dead(Bef, I, Vdb), + {[{test,is_map,{f,Fail},[Arg]}],Aft,St}; test_cg(Test, As, Fail, I, Vdb, Bef, St) -> Args = cg_reg_args(As, Bef), Aft = clear_dead(Bef, I, Vdb), @@ -1155,19 +1172,15 @@ call_cg(Func, As, Rs, Le, Vdb, Bef, St0) -> %% Inside a guard. The only allowed function call is to %% erlang:error/1,2. We will generate the following code: %% - %% jump FailureLabel %% move {atom,ok} DestReg - %% - %% The 'move' instruction will never be executed, but we - %% generate it anyway in case the beam_validator is run - %% on unoptimized code. + %% jump FailureLabel {remote,{atom,erlang},{atom,error}} = Func, %Assertion. [{var,DestVar}] = Rs, Int0 = clear_dead(Bef, Le#l.i, Vdb), Reg = put_reg(DestVar, Int0#sr.reg), Int = Int0#sr{reg=Reg}, Dst = fetch_reg(DestVar, Reg), - {[{jump,{f,Fail}},{move,{atom,ok},Dst}], + {[{move,{atom,ok},Dst},{jump,{f,Fail}}], clear_dead(Int, Le#l.i, Vdb),St0}; #cg{} -> %% Ordinary function call in a function body. @@ -1545,7 +1558,7 @@ set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef, Fail = {f,Bfail}, {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St), - SrcReg = cg_reg_arg(Map,Int0), + SrcReg = cg_reg_arg_prefer_y(Map, Int0), Line = line(Le#l.a), List = [cg_reg_arg(K,Int0),cg_reg_arg(V,Int0)], @@ -1572,7 +1585,7 @@ set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef, Fail = {f,Bfail}, {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St), - SrcReg = cg_reg_arg(Map,Int0), + SrcReg = cg_reg_arg_prefer_y(Map, Int0), Line = line(Le#l.a), %% fetch registers for values to be put into the map @@ -1845,6 +1858,9 @@ cg_reg_args(As, Bef) -> [cg_reg_arg(A, Bef) || A <- As]. cg_reg_arg({var,V}, Bef) -> fetch_var(V, Bef); cg_reg_arg(Literal, _) -> Literal. +cg_reg_arg_prefer_y({var,V}, Bef) -> fetch_var_prefer_y(V, Bef); +cg_reg_arg_prefer_y(Literal, _) -> Literal. + %% cg_setup_call([Arg], Bef, Cur, Vdb) -> {[Instr],Aft}. %% Do the complete setup for a call/enter. @@ -2086,6 +2102,12 @@ fetch_var(V, Sr) -> error -> fetch_stack(V, Sr#sr.stk) end. +fetch_var_prefer_y(V, #sr{reg=Reg,stk=Stk}) -> + case find_stack(V, Stk) of + {ok,R} -> R; + error -> fetch_reg(V, Reg) + end. + load_vars(Vs, Regs) -> foldl(fun ({var,V}, Rs) -> put_reg(V, Rs) end, Regs, Vs). @@ -2159,11 +2181,11 @@ fetch_stack(Var, Stk) -> fetch_stack(Var, Stk, 0). fetch_stack(V, [{V}|_], I) -> {yy,I}; fetch_stack(V, [_|Stk], I) -> fetch_stack(V, Stk, I+1). -% find_stack(Var, Stk) -> find_stack(Var, Stk, 0). +find_stack(Var, Stk) -> find_stack(Var, Stk, 0). -% find_stack(V, [{V}|Stk], I) -> {ok,{yy,I}}; -% find_stack(V, [O|Stk], I) -> find_stack(V, Stk, I+1); -% find_stack(V, [], I) -> error. +find_stack(V, [{V}|_], I) -> {ok,{yy,I}}; +find_stack(V, [_|Stk], I) -> find_stack(V, Stk, I+1); +find_stack(_, [], _) -> error. on_stack(V, Stk) -> keymember(V, 1, Stk). |