diff options
Diffstat (limited to 'kernel/cbytegen.ml')
| -rw-r--r-- | kernel/cbytegen.ml | 197 |
1 files changed, 135 insertions, 62 deletions
diff --git a/kernel/cbytegen.ml b/kernel/cbytegen.ml index 77eac9ee..b1fc0c85 100644 --- a/kernel/cbytegen.ml +++ b/kernel/cbytegen.ml @@ -91,9 +91,19 @@ open Pre_env (* In Cfxe_t accumulators, we need to store [fcofixi] for testing *) (* conversion of cofixpoints (which is intentional). *) +module Config = struct + let stack_threshold = 256 (* see byterun/coq_memory.h *) + let stack_safety_margin = 15 +end + type argument = ArgConstr of Constr.t | ArgUniv of Univ.Level.t -let empty_fv = { size= 0; fv_rev = [] } +let empty_fv = { size= 0; fv_rev = []; fv_fwd = FvMap.empty } +let push_fv d e = { + size = e.size + 1; + fv_rev = d :: e.fv_rev; + fv_fwd = FvMap.add d e.size e.fv_fwd; +} let fv r = !(r.in_env) @@ -107,6 +117,26 @@ let empty_comp_env ?(univs=0) ()= in_env = ref empty_fv } +(* Maximal stack size reached during the current function body. Used to + reallocate the stack if we lack space. *) +let max_stack_size = ref 0 + +let set_max_stack_size stack_size = + if stack_size > !max_stack_size then + max_stack_size := stack_size + +let ensure_stack_capacity f x = + let old = !max_stack_size in + max_stack_size := 0; + let code = f x in + let used_safe = + !max_stack_size + Config.stack_safety_margin + in + max_stack_size := old; + if used_safe > Config.stack_threshold then + Kensurestackcapacity used_safe :: code + else code + (*i Creation functions for comp_env *) let rec add_param n sz l = @@ -184,20 +214,15 @@ let push_local sz r = in_stack = (sz + 1) :: r.in_stack } (*i Compilation of variables *) -let find_at f l = - let rec aux n = function - | [] -> raise Not_found - | hd :: tl -> if f hd then n else aux (n + 1) tl - in aux 1 l +let find_at fv env = FvMap.find fv env.fv_fwd let pos_named id r = let env = !(r.in_env) in let cid = FVnamed id in - let f = function FVnamed id' -> Id.equal id id' | _ -> false in - try Kenvacc(r.offset + env.size - (find_at f env.fv_rev)) + try Kenvacc(r.offset + find_at cid env) with Not_found -> let pos = env.size in - r.in_env := { size = pos+1; fv_rev = cid:: env.fv_rev}; + r.in_env := push_fv cid env; Kenvacc (r.offset + pos) let pos_rel i r sz = @@ -212,11 +237,10 @@ let pos_rel i r sz = let i = i - r.nb_rec in let db = FVrel(i) in let env = !(r.in_env) in - let f = function FVrel j -> Int.equal i j | _ -> false in - try Kenvacc(r.offset + env.size - (find_at f env.fv_rev)) + try Kenvacc(r.offset + find_at db env) with Not_found -> let pos = env.size in - r.in_env := { size = pos+1; fv_rev = db:: env.fv_rev}; + r.in_env := push_fv db env; Kenvacc(r.offset + pos) let pos_universe_var i r sz = @@ -224,15 +248,11 @@ let pos_universe_var i r sz = Kacc (sz - r.nb_stack - (r.nb_uni_stack - i)) else let env = !(r.in_env) in - let f = function - | FVuniv_var u -> Int.equal i u - | _ -> false - in - try Kenvacc (r.offset + env.size - (find_at f env.fv_rev)) + let db = FVuniv_var i in + try Kenvacc (r.offset + find_at db env) with Not_found -> let pos = env.size in - let db = FVuniv_var i in - r.in_env := { size = pos + 1; fv_rev = db::env.fv_rev } ; + r.in_env := push_fv db env; Kenvacc(r.offset + pos) (*i Examination of the continuation *) @@ -375,14 +395,28 @@ let const_bn tag args = else Const_bn(last_variant_tag, Array.append [|Const_b0 (tag - last_variant_tag) |] args) - -let code_makeblock arity tag cont = +(* +If [tag] hits the OCaml limitation for non constant constructors, we switch to +another representation for the remaining constructors: +[last_variant_tag|tag - last_variant_tag|args] + +We subtract last_variant_tag for efficiency of match interpretation. + *) + +let nest_block tag arity cont = + Kconst (Const_b0 (tag - last_variant_tag)) :: + Kmakeblock(arity+1, last_variant_tag) :: cont + +let code_makeblock ~stack_size ~arity ~tag cont = if tag < last_variant_tag then Kmakeblock(arity, tag) :: cont - else - Kpush :: Kconst (Const_b0 (tag - last_variant_tag)) :: - Kmakeblock(arity+1, last_variant_tag) :: cont + else begin + set_max_stack_size (stack_size + 1); + Kpush :: nest_block tag arity cont + end +(* [code_construct] compiles an abstracted constructor dropping parameters and + updates [fun_code] *) (* Inv : nparam + arity > 0 *) let code_construct tag nparams arity cont = let f_cont = @@ -391,11 +425,11 @@ let code_construct tag nparams arity cont = [Kconst (Const_b0 tag); Kreturn 0] else if tag < last_variant_tag then [Kacc 0; Kpop 1; Kmakeblock(arity, tag); Kreturn 0] - else - [Kconst (Const_b0 (tag - last_variant_tag)); - Kmakeblock(arity+1, last_variant_tag); Kreturn 0]) + else + nest_block tag arity [Kreturn 0]) in let lbl = Label.create() in + (* No need to grow the stack here, as the function does not push stuff. *) fun_code := [Ksequence (add_grab (nparams+arity) lbl f_cont,!fun_code)]; Kclosure(lbl,0) :: cont @@ -511,6 +545,7 @@ let comp_args comp_expr reloc args sz cont = done; !c +(* Precondition: args not empty *) let comp_app comp_fun comp_arg reloc f args sz cont = let nargs = Array.length args in match is_tailcall cont with @@ -540,11 +575,12 @@ let compile_fv_elem reloc fv sz cont = let rec compile_fv reloc l sz cont = match l with | [] -> cont - | [fvn] -> compile_fv_elem reloc fvn sz cont + | [fvn] -> set_max_stack_size (sz + 1); compile_fv_elem reloc fvn sz cont | fvn :: tl -> compile_fv_elem reloc fvn sz (Kpush :: compile_fv reloc tl (sz + 1) cont) + (* Compiling constants *) let rec get_alias env kn = @@ -559,6 +595,7 @@ let rec get_alias env kn = (* sz is the size of the local stack *) let rec compile_constr reloc c sz cont = + set_max_stack_size sz; match kind_of_term c with | Meta _ -> invalid_arg "Cbytegen.compile_constr : Meta" | Evar _ -> invalid_arg "Cbytegen.compile_constr : Evar" @@ -607,6 +644,7 @@ let rec compile_constr reloc c sz cont = compile_str_cst reloc (Bstrconst (Const_sorts (Type uglob))) sz cont else let compile_get_univ reloc idx sz cont = + set_max_stack_size sz; compile_fv_elem reloc (FVuniv_var idx) sz cont in comp_app compile_str_cst compile_get_univ reloc @@ -626,7 +664,8 @@ let rec compile_constr reloc c sz cont = let r_fun = comp_env_fun arity in let lbl_fun = Label.create() in let cont_fun = - compile_constr r_fun body arity [Kreturn arity] in + ensure_stack_capacity (compile_constr r_fun body arity) [Kreturn arity] + in fun_code := [Ksequence(add_grab arity lbl_fun cont_fun,!fun_code)]; let fv = fv r_fun in compile_fv reloc fv.fv_rev sz (Kclosure(lbl_fun,fv.size) :: cont) @@ -646,9 +685,10 @@ let rec compile_constr reloc c sz cont = (* Compilation des types *) let env_type = comp_env_fix_type rfv in for i = 0 to ndef - 1 do - let lbl,fcode = - label_code - (compile_constr env_type type_bodies.(i) 0 [Kstop]) in + let fcode = + ensure_stack_capacity (compile_constr env_type type_bodies.(i) 0) [Kstop] + in + let lbl,fcode = label_code fcode in lbl_types.(i) <- lbl; fun_code := [Ksequence(fcode,!fun_code)] done; @@ -658,7 +698,8 @@ let rec compile_constr reloc c sz cont = let arity = List.length params in let env_body = comp_env_fix ndef i arity rfv in let cont1 = - compile_constr env_body body arity [Kreturn arity] in + ensure_stack_capacity (compile_constr env_body body arity) [Kreturn arity] + in let lbl = Label.create () in lbl_bodies.(i) <- lbl; let fcode = add_grabrec rec_args.(i) arity lbl cont1 in @@ -676,9 +717,10 @@ let rec compile_constr reloc c sz cont = let rfv = ref empty_fv in let env_type = comp_env_cofix_type ndef rfv in for i = 0 to ndef - 1 do - let lbl,fcode = - label_code - (compile_constr env_type type_bodies.(i) 0 [Kstop]) in + let fcode = + ensure_stack_capacity (compile_constr env_type type_bodies.(i) 0) [Kstop] + in + let lbl,fcode = label_code fcode in lbl_types.(i) <- lbl; fun_code := [Ksequence(fcode,!fun_code)] done; @@ -688,14 +730,17 @@ let rec compile_constr reloc c sz cont = let arity = List.length params in let env_body = comp_env_cofix ndef arity rfv in let lbl = Label.create () in - let cont1 = - compile_constr env_body body (arity+1) (cont_cofix arity) in - let cont2 = - add_grab (arity+1) lbl cont1 in + let comp arity = + (* 4 stack slots are needed to update the cofix when forced *) + set_max_stack_size (arity + 4); + compile_constr env_body body (arity+1) (cont_cofix arity) + in + let cont = ensure_stack_capacity comp arity in lbl_bodies.(i) <- lbl; - fun_code := [Ksequence(cont2,!fun_code)]; + fun_code := [Ksequence(add_grab (arity+1) lbl cont,!fun_code)]; done; let fv = !rfv in + set_max_stack_size (sz + fv.size + ndef + 2); compile_fv reloc fv.fv_rev sz (Kclosurecofix(fv.size, init, lbl_types, lbl_bodies) :: cont) @@ -713,9 +758,11 @@ let rec compile_constr reloc c sz cont = let lbl_eblocks = Array.make neblock Label.no in let branch1,cont = make_branch cont in (* Compiling return type *) - let lbl_typ,fcode = - label_code (compile_constr reloc t sz [Kpop sz; Kstop]) - in fun_code := [Ksequence(fcode,!fun_code)]; + let fcode = + ensure_stack_capacity (compile_constr reloc t sz) [Kpop sz; Kstop] + in + let lbl_typ,fcode = label_code fcode in + fun_code := [Ksequence(fcode,!fun_code)]; (* Compiling branches *) let lbl_sw = Label.create () in let sz_b,branch,is_tailcall = @@ -725,14 +772,9 @@ let rec compile_constr reloc c sz cont = sz, branch1, true | _ -> sz+3, Kjump, false in - let annot = {ci = ci; rtbl = tbl; tailcall = is_tailcall} in - (* Compiling branch for accumulators *) - let lbl_accu, code_accu = - label_code(Kmakeswitchblock(lbl_typ,lbl_sw,annot,sz) :: branch::cont) - in - lbl_blocks.(0) <- lbl_accu; - let c = ref code_accu in - (* perform the extra match if needed (to many block constructors) *) + + let c = ref cont in + (* Perform the extra match if needed (too many block constructors) *) if neblock <> 0 then begin let lbl_b, code_b = label_code ( @@ -762,14 +804,34 @@ let rec compile_constr reloc c sz cont = compile_constr reloc branchs.(i) (sz_b+arity) (Kappterm(arity,sz_appterm) :: !c) in let code_b = - if tag < last_variant_tag then Kpushfields arity :: code_b - else Kacc 0::Kpop 1::Kpushfields(arity+1)::Kpop 1::code_b in + if tag < last_variant_tag then begin + set_max_stack_size (sz_b + arity); + Kpushfields arity :: code_b + end + else begin + set_max_stack_size (sz_b + arity + 1); + Kacc 0::Kpop 1::Kpushfields(arity+1)::Kpop 1::code_b + end + in let lbl_b,code_b = label_code code_b in if tag < last_variant_tag then lbl_blocks.(tag) <- lbl_b else lbl_eblocks.(tag - last_variant_tag) <- lbl_b; c := code_b done; - c := Klabel lbl_sw :: Kswitch(lbl_consts,lbl_blocks) :: !c; + + let annot = + {ci = ci; rtbl = tbl; tailcall = is_tailcall; + max_stack_size = !max_stack_size - sz} + in + + (* Compiling branch for accumulators *) + let lbl_accu, code_accu = + set_max_stack_size (sz+3); + label_code(Kmakeswitchblock(lbl_typ,lbl_sw,annot,sz) :: branch :: !c) + in + lbl_blocks.(0) <- lbl_accu; + + c := Klabel lbl_sw :: Kswitch(lbl_consts,lbl_blocks) :: code_accu; let code_sw = match branch1 with (* spiwack : branch1 can't be a lbl anymore it's a Branch instead @@ -786,12 +848,14 @@ let rec compile_constr reloc c sz cont = code_sw) and compile_str_cst reloc sc sz cont = + set_max_stack_size sz; match sc with | Bconstr c -> compile_constr reloc c sz cont | Bstrconst sc -> Kconst sc :: cont | Bmakeblock(tag,args) -> - let nargs = Array.length args in - comp_args compile_str_cst reloc args sz (code_makeblock nargs tag cont) + let arity = Array.length args in + let cont = code_makeblock ~stack_size:(sz+arity-1) ~arity ~tag cont in + comp_args compile_str_cst reloc args sz cont | Bconstruct_app(tag,nparams,arity,args) -> if Int.equal (Array.length args) 0 then code_construct tag nparams arity cont @@ -805,6 +869,7 @@ and compile_str_cst reloc sc sz cont = (* spiwack : compilation of constants with their arguments. Makes a special treatment with 31-bit integer addition *) and compile_get_global reloc (kn,u) sz cont = + set_max_stack_size sz; let kn = get_alias !global_env kn in if Univ.Instance.is_empty u then Kgetglobal kn :: cont @@ -813,11 +878,13 @@ and compile_get_global reloc (kn,u) sz cont = compile_universe reloc () (Univ.Instance.to_array u) sz cont and compile_universe reloc uni sz cont = + set_max_stack_size sz; match Univ.Level.var_index uni with | None -> Kconst (Const_univ_level uni) :: cont | Some idx -> pos_universe_var idx reloc sz :: cont and compile_const reloc kn u args sz cont = + set_max_stack_size sz; let nargs = Array.length args in (* spiwack: checks if there is a specific way to compile the constant if there is not, Not_found is raised, and the function @@ -879,7 +946,7 @@ let compile fail_on_error ?universes:(universes=0) env c = let reloc, init_code = if Int.equal universes 0 then let reloc = empty_comp_env () in - reloc, compile_constr reloc c 0 cont + reloc, ensure_stack_capacity (compile_constr reloc c 0) cont else (* We are going to generate a lambda, but merge the universe closure * with the function closure if it exists. @@ -896,18 +963,24 @@ let compile fail_on_error ?universes:(universes=0) env c = let r_fun = comp_env_fun ~univs:universes arity in let lbl_fun = Label.create () in let cont_fun = - compile_constr r_fun body full_arity [Kreturn full_arity] + ensure_stack_capacity (compile_constr r_fun body full_arity) + [Kreturn full_arity] in fun_code := [Ksequence(add_grab full_arity lbl_fun cont_fun,!fun_code)]; let fv = fv r_fun in - reloc, compile_fv reloc fv.fv_rev 0 (Kclosure(lbl_fun,fv.size) :: cont) + let init_code = + ensure_stack_capacity (compile_fv reloc fv.fv_rev 0) + (Kclosure(lbl_fun,fv.size) :: cont) + in + reloc, init_code in let fv = List.rev (!(reloc.in_env).fv_rev) in (if !Flags.dump_bytecode then - Pp.msg_debug (dump_bytecodes init_code !fun_code fv)) ; + Feedback.msg_debug (dump_bytecodes init_code !fun_code fv)) ; Some (init_code,!fun_code, Array.of_list fv) with TooLargeInductive tname -> - let fn = if fail_on_error then Errors.errorlabstrm "compile" else Pp.msg_warning in + let fn = if fail_on_error then CErrors.errorlabstrm "compile" else + (fun x -> Feedback.msg_warning x) in (Pp.(fn (str "Cannot compile code for virtual machine as it uses inductive " ++ Id.print tname ++ str str_max_constructors)); |