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-rw-r--r--src/codegen.ml186
-rw-r--r--src/mips.ml6
-rw-r--r--src/mips.mli6
3 files changed, 127 insertions, 71 deletions
diff --git a/src/codegen.ml b/src/codegen.ml
index 70ed095..5dde4d7 100644
--- a/src/codegen.ml
+++ b/src/codegen.ml
@@ -3,11 +3,19 @@ open Typing
exception Very_bad_error of string
+(* Convention pour les registres :
+ - a0, a1, a2, a3 : contiennent les (éventuels) 4 premiers arguments de la fonction
+ - v0 : contient la valeur de retour des fonctions
+ - v0-v1, t0-t9, s0-s1 : utilisés pour les calculs
+ Tous les registres doivent être sauvés par l'appellant
+*)
+
(* Environnement pour accéder aux variables *)
type whereis_var =
| VGlobal
| VStack of int (* position relative à $fp *)
| VStackByRef of int
+ | VRegister of register
type cg_env = {
c_penv : env;
@@ -28,11 +36,20 @@ let id =
(* Génération de code des machins *)
-let cr r a = if a then lw r areg (0, r) else nop (* conditionnally read *)
+type expr_type =
+ | Addr (* top register contains address of value *)
+ | Copy (* top register contains copy of value *)
+ | Value of register (* other register is home to the value *)
+
+let cr r a = match a with (* conditionnally read *)
+ | Addr -> lw r areg (0, r)
+ | Copy -> nop
+ | Value(k) -> if r <> k then move r k else nop
+
+let use_regs = [ v0; v1; t0; t1; t2; t3; t4; t5; t6; t7; t8; t9 ]
+let spare_reg = s0
+let spare_reg2 = s1
-let use_regs = [ a0; a1; a2; a3; t0; t1; t2; t3 ]
-let spare_reg = v0
-let spare_reg2 = v1
(* Convention : doit garder $sp invariant ; renvoie le résultat dans le premier registre de free_regs *)
let rec gen_expr env free_regs save_regs e =
@@ -45,15 +62,16 @@ let rec gen_expr env free_regs save_regs e =
(fun code r -> code ++ pop r) nop save_regs in
(* the generator... *)
match e.te_desc with
- | TEInt(k) -> li r k, false
- | TENull -> move r zero, false
- | TEThis -> (* convention : this is always the last-pushed argument *)
- lw r areg (8, fp), false
+ | TEInt(k) -> li r k, Copy
+ | TENull -> move r zero, Copy
+ | TEThis -> (* convention : this is always the last-pushed argument, so in a0 *)
+ lw r areg (8, fp), Copy
| TEIdent(i) ->
begin match Smap.find i env.c_names with
- | VGlobal -> la r alab i, true
- | VStack(i) -> la r areg (i, fp), true
- | VStackByRef(i) -> lw r areg (i, fp), true
+ | VGlobal -> la r alab i, Addr
+ | VStack(i) -> la r areg (i, fp), Addr
+ | VStackByRef(i) -> lw r areg (i, fp), Addr
+ | VRegister(r) -> nop, Value r
end
| TEAssign(e1, e2) ->
let t2, ae2 = gen_expr env free_regs save_regs e2 in
@@ -61,47 +79,73 @@ let rec gen_expr env free_regs save_regs e =
begin match more with
| [] ->
let t1, ae1 = gen_expr env free_regs save_regs e1 in
- assert ae1;
- t1 ++ push r ++ t2 ++ pop spare_reg ++ sw r areg (0, spare_reg), false
+ begin match ae1 with
+ | Addr -> t1 ++ push r ++ t2 ++ pop spare_reg ++ sw r areg (0, spare_reg), Copy
+ | Value k when t1 = nop && k <> r -> t2 ++ move k r, Copy
+ | _ -> assert false
+ end
| b::_ ->
let t1, ae1 = gen_expr env more (r::save_regs) e1 in
- assert ae1;
- t2 ++ t1 ++ sw r areg (0, b), false
+ begin match ae1 with
+ | Addr -> t2 ++ t1 ++ sw r areg (0, b), Copy
+ | Value k when t1 = nop && k <> r -> t2 ++ move k r, Copy
+ | _ -> assert false
+ end
end
| TECallFun(id, args, b) ->
let code = List.fold_left
(fun code (arg, byref) ->
- let c, addr = gen_expr_a0 env arg in
- assert (addr || not byref);
- c ++ cr a0 (addr && not byref) ++ push a0 ++ code) nop args in
+ let c, addr = gen_expr_v0 env arg in
+ assert (addr = Addr || not byref);
+ c ++ (if not byref then cr v0 addr else nop) ++ push v0 ++ code) nop args in
code_save_regs ++ code ++ jal id ++ popn (4 * (List.length args))
- ++ (if r <> a0 then move r a0 else nop) ++ code_restore_regs, b
+ ++ (if r <> v0 then move r v0 else nop) ++ code_restore_regs, if b then Addr else Copy
| TECallVirtual(obj, fi, args, b) ->
let code = List.fold_left
(fun code (arg, byref) ->
- let c, addr = gen_expr_a0 env arg in
- assert (addr || not byref);
- c ++ cr a0 (addr && not byref) ++ push a0 ++ code) nop args in
- let code2, a = gen_expr_a0 env obj in
- assert a;
+ let c, addr = gen_expr_v0 env arg in
+ assert (addr = Addr || not byref);
+ c ++ (if not byref then cr v0 addr else nop) ++ push v0 ++ code) nop args in
+ let code2, a = gen_expr_v0 env obj in
+ assert (a = Addr);
code_save_regs
- ++ code ++ code2 ++ push a0 ++ lw a0 areg (0, a0) ++ lw a0 areg (fi, a0)
- ++ jalr a0 ++ popn (4 * (1 + List.length args))
- ++ (if r <> a0 then move r a0 else nop) ++ code_restore_regs, b
+ ++ code ++ code2 ++ push v0 ++ lw v0 areg (0, v0) ++ lw v0 areg (fi, v0)
+ ++ jalr v0 ++ popn (4 * (1 + List.length args))
+ ++ (if r <> v0 then move r v0 else nop) ++ code_restore_regs, if b then Addr else Copy
| TEUnary (x, e) ->
let t, a = gen_expr env free_regs save_regs e in
begin match x with
- | Ast.Deref -> t ++ cr r a, true
- | Ast.Ref -> assert a; t, false
- | Ast.Plus -> t ++ cr r a, false
- | Ast.Minus -> t ++ cr r a ++ neg r r, false
- | Ast.Not -> t ++ cr r a ++ not_ r r, false
- | Ast.PreIncr -> assert a; t ++ lw spare_reg areg (0, r) ++ add spare_reg spare_reg oi 1 ++ sw spare_reg areg (0, r), true
- | Ast.PreDecr -> assert a; t ++ lw spare_reg areg (0, r) ++ sub spare_reg spare_reg oi 1 ++ sw spare_reg areg (0, r), true
- | Ast.PostIncr -> assert a; t ++ move spare_reg r ++ lw spare_reg2 areg(0, spare_reg) ++ move r spare_reg2 ++
- add spare_reg2 spare_reg2 oi 1 ++ sw spare_reg2 areg(0, spare_reg), false
- | Ast.PostDecr -> assert a; t ++ move spare_reg r ++ lw spare_reg2 areg(0, spare_reg) ++ move r spare_reg2 ++
- sub spare_reg2 spare_reg2 oi 1 ++ sw spare_reg2 areg(0, spare_reg), false
+ | Ast.Deref -> t ++ cr r a, Addr
+ | Ast.Ref -> assert (a = Addr); t, Copy
+ | Ast.Plus -> t ++ cr r a, Copy
+ | Ast.Minus -> t ++ cr r a ++ neg r r, Copy
+ | Ast.Not -> t ++ cr r a ++ not_ r r, Copy
+ | Ast.PreIncr ->
+ begin match a with
+ | Addr -> t ++ lw spare_reg areg (0, r) ++ add spare_reg spare_reg oi 1 ++ sw spare_reg areg (0, r), Addr
+ | Value v when t = nop && v <> r -> add v v oi 1 ++ move r v, Copy
+ | _ -> assert false
+ end
+ | Ast.PreDecr ->
+ begin match a with
+ | Addr -> t ++ lw spare_reg areg (0, r) ++ sub spare_reg spare_reg oi 1 ++ sw spare_reg areg (0, r), Addr
+ | Value v when t = nop && v <> r -> sub v v oi 1 ++ move r v, Copy
+ | _ -> assert false
+ end
+ | Ast.PostIncr ->
+ begin match a with
+ | Addr -> t ++ move spare_reg r ++ lw spare_reg2 areg(0, spare_reg) ++ move r spare_reg2 ++
+ add spare_reg2 spare_reg2 oi 1 ++ sw spare_reg2 areg(0, spare_reg), Copy
+ | Value v when t = nop && v <> r -> move r v ++ add v v oi 1, Copy
+ | _ -> assert false
+ end
+ | Ast.PostDecr ->
+ begin match a with
+ | Addr -> t ++ move spare_reg r ++ lw spare_reg2 areg(0, spare_reg) ++ move r spare_reg2 ++
+ sub spare_reg2 spare_reg2 oi 1 ++ sw spare_reg2 areg(0, spare_reg), Copy
+ | Value v when t = nop && v <> r -> move r v ++ sub v v oi 1, Copy
+ | _ -> assert false
+ end
end
| TEBinary(e1, op, e2) when op <> Ast.Lor && op <> Ast.Land ->
let rb, precode = match more with
@@ -131,67 +175,67 @@ let rec gen_expr env free_regs save_regs e =
| Ast.Gt -> sgt r r rb
| Ast.Ge -> sge r r rb
| _ -> assert false
- ), false
+ ), Copy
| TEBinary(e1, op, e2) (* when op = Ast.Lor || op = Ast.Land *) ->
let t1, ae1 = gen_expr env free_regs save_regs e1 in
let t2, ae2 = gen_expr env free_regs save_regs e2 in
let t1 = t1 ++ cr r ae1 in
let t2 = t2 ++ cr r ae2 in
let lazy_lbl = id "_lazy" in
- t1 ++ (if op = Ast.Lor then bnez r lazy_lbl else beqz r lazy_lbl) ++ t2 ++ label lazy_lbl ++ sne r r zero, false
+ t1 ++ (if op = Ast.Lor then bnez r lazy_lbl else beqz r lazy_lbl) ++ t2 ++ label lazy_lbl ++ sne r r zero, Copy
| TEMember(e, i) ->
let c, a = gen_expr env free_regs save_regs e in
if i <> 0 then begin
- assert a;
- c ++ la r areg (i, r), true
+ assert (a = Addr);
+ c ++ la r areg (i, r), Addr
end else
c, a
| TEPointerCast(e, i) ->
let c, a = gen_expr env free_regs save_regs e in
- c ++ cr r a ++ (if i = 0 then nop else la r areg (i, r)), false
+ c ++ cr r a ++ (if i = 0 then nop else la r areg (i, r)), Copy
| TENew(cls, constr, args) ->
let args_code = List.fold_left
(fun code (arg, byref) ->
- let c, addr = gen_expr_a0 env arg in
- assert (addr || not byref);
- c ++ cr a0 (addr && not byref) ++ push a0 ++ code) nop args in
+ let c, addr = gen_expr_v0 env arg in
+ assert (addr = Addr || not byref);
+ c ++ (if not byref then cr v0 addr else nop) ++ push v0 ++ code) nop args in
let alloc = li v0 9 ++ li a0 cls.tc_size ++ syscall in
code_save_regs ++ args_code ++ alloc ++ push v0 ++ jal constr
- ++ pop r ++ popn (4 * List.length args) ++ code_restore_regs, false
+ ++ pop r ++ popn (4 * List.length args) ++ code_restore_regs, Copy
-and gen_expr_a0 env = gen_expr env use_regs []
+and gen_expr_v0 env = gen_expr env use_regs []
let rec gen_stmt env = function
| TSEmpty -> nop, nop, env
| TSExpr(e) ->
- comment "expr" ++ (fst (gen_expr_a0 env e)), nop, env
+ comment "expr" ++ (fst (gen_expr_v0 env e)), nop, env
| TSIf(cond, s1, s2) ->
- let c, a = gen_expr_a0 env cond in
+ let c, a = gen_expr_v0 env cond in
let l_else = id "_cond_then" in
let l_end = id "_cond_end" in
let c_then, d_then, _ = gen_stmt env s1 in
let c_else, d_else, _ = gen_stmt env s2 in
- comment "if" ++ c ++ cr a0 a ++ beqz a0 l_else ++ c_then ++ b l_end ++
+ comment "if" ++ c ++ cr v0 a ++ beqz v0 l_else ++ c_then ++ b l_end ++
label l_else ++ c_else ++ label l_end, d_then ++ d_else, env
| TSWhile(cond, body) ->
- let c, a = gen_expr_a0 env cond in
+ let c, a = gen_expr_v0 env cond in
let l_begin = id "_while_begin" in
let l_cond = id "_while_cond" in
let c_body, d_body, _ = gen_stmt env body in
comment "while" ++ b l_cond ++ label l_begin ++ c_body ++
- label l_cond ++ c ++ cr a0 a ++ bnez a0 l_begin, d_body, env
+ label l_cond ++ c ++ cr v0 a ++ bnez v0 l_begin, d_body, env
| TSFor(before, cond, after, body) ->
let l_begin = id "_for_begin" in
let l_cond = id "_for_cond" in
let c_before = List.fold_left
- (fun code expr -> let c, _ = gen_expr_a0 env expr in code ++ c) nop before in
+ (fun code expr -> let c, _ = gen_expr_v0 env expr in code ++ c) nop before in
let c_after = List.fold_left
- (fun code expr -> let c, _ = gen_expr_a0 env expr in code ++ c) nop after in
+ (fun code expr -> let c, _ = gen_expr_v0 env expr in code ++ c) nop after in
let c_cond = match cond with
| None -> b l_begin
- | Some x -> let c, a = gen_expr_a0 env x in
- c ++ cr a0 a ++ bnez a0 l_begin in
+ | Some x -> let c, a = gen_expr_v0 env x in
+ c ++ cr v0 a ++ bnez v0 l_begin in
let c_body, d_body, _ = gen_stmt env body in
comment "for" ++ c_before ++ b l_cond ++ label l_begin ++ c_body ++ c_after ++ label l_cond
++ c_cond, d_body, env
@@ -201,9 +245,9 @@ let rec gen_stmt env = function
| TSReturn (None) ->
comment "return" ++ b "_return", nop, env
| TSReturn (Some e) ->
- let c, a = gen_expr_a0 env e in
- assert (a || not env.c_ret_ref);
- comment "return" ++ c ++ cr a0 (not env.c_ret_ref && a) ++ b "_return", nop, env
+ let c, a = gen_expr_v0 env e in
+ assert (a = Addr || not env.c_ret_ref);
+ comment "return" ++ c ++ (if not env.c_ret_ref then cr v0 a else nop) ++ b "_return", nop, env
| TSDeclare (ty, id) ->
let s = type_size env.c_penv ty in
let new_fp_used = env.c_fp_used + s in
@@ -213,8 +257,8 @@ let rec gen_stmt env = function
let c = get_c env.c_penv i in
let cproto = List.find (fun p -> p.tp_ret_type = None && p.tp_name = i && p.tp_args = []) c.tc_methods in
sub sp sp oi s ++
- la a0 areg (pos, fp) ++
- push a0 ++
+ la v0 areg (pos, fp) ++
+ push v0 ++
jal cproto.tp_unique_ident
| _ -> push zero
in
@@ -229,10 +273,10 @@ let rec gen_stmt env = function
let code =
let args_code = List.fold_left
(fun code (arg, byref) ->
- let c, addr = gen_expr_a0 env arg in
- assert (addr || not byref);
- c ++ cr a0 (addr && not byref) ++ push a0 ++ code) nop args in
- sub sp sp oi cls.tc_size ++ args_code ++ la a0 areg(pos, fp) ++ push a0 ++ jal constr ++
+ let c, addr = gen_expr_v0 env arg in
+ assert (addr = Addr || not byref);
+ c ++ (if not byref then cr v0 addr else nop) ++ push v0 ++ code) nop args in
+ sub sp sp oi cls.tc_size ++ args_code ++ la v0 areg(pos, fp) ++ push v0 ++ jal constr ++
popn (4 * (List.length args + 1))
in
comment ("declare " ^ id) ++ code, nop, {
@@ -245,9 +289,9 @@ let rec gen_stmt env = function
assert (s = 4);
let new_fp_used = env.c_fp_used + 4 in
let pos = - new_fp_used in
- let code, a = gen_expr_a0 env e in
- assert (a || not ref);
- comment ("declare " ^ id) ++ sub sp sp oi 4 ++ code ++ cr a0 (a && not ref) ++ sw a0 areg (pos, fp), nop, {
+ let code, a = gen_expr_v0 env e in
+ assert (a = Addr || not ref);
+ comment ("declare " ^ id) ++ sub sp sp oi 4 ++ code ++ (if not ref then cr v0 a else nop) ++ sw v0 areg (pos, fp), nop, {
c_penv = env.c_penv;
c_names = Smap.add id (if ref then VStackByRef pos else VStack pos) env.c_names;
c_ret_ref = env.c_ret_ref;
@@ -257,8 +301,8 @@ let rec gen_stmt env = function
(fun (text, data) s ->
match s with
| TSEExpr(e) ->
- let t, a = gen_expr_a0 env e in
- text ++ t ++ cr a0 a ++ li v0 1 ++ syscall, data
+ let t, a = gen_expr_v0 env e in
+ text ++ t ++ cr v0 a ++ move a0 v0 ++ li v0 1 ++ syscall, data
| TSEStr(s) ->
let l, d =
if Hashtbl.mem strings s then
diff --git a/src/mips.ml b/src/mips.ml
index 5fe310c..0359728 100644
--- a/src/mips.ml
+++ b/src/mips.ml
@@ -17,6 +17,12 @@ let t0 : register = "$t0"
let t1 : register = "$t1"
let t2 : register = "$t2"
let t3 : register = "$t3"
+let t4 : register = "$t4"
+let t5 : register = "$t5"
+let t6 : register = "$t6"
+let t7 : register = "$t7"
+let t8 : register = "$t8"
+let t9 : register = "$t9"
let s0 : register = "$s0"
let s1 : register = "$s1"
let ra : register = "$ra"
diff --git a/src/mips.mli b/src/mips.mli
index a42f1ce..f1e39d6 100644
--- a/src/mips.mli
+++ b/src/mips.mli
@@ -57,6 +57,12 @@ val t0 : register
val t1 : register
val t2 : register
val t3 : register
+val t4 : register
+val t5 : register
+val t6 : register
+val t7 : register
+val t8 : register
+val t9 : register
val s0 : register
val s1 : register
val ra : register