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-rw-r--r--src/codegen.ml191
1 files changed, 120 insertions, 71 deletions
diff --git a/src/codegen.ml b/src/codegen.ml
index 5042339..6ada77a 100644
--- a/src/codegen.ml
+++ b/src/codegen.ml
@@ -3,6 +3,8 @@ open Typing
exception Very_bad_error of string
+exception Reference_register of register
+
(* 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 (rien de particulier pour un constructeur)
@@ -35,6 +37,7 @@ type cg_env = {
c_fp_used : int;
c_need_fp : bool ref;
c_save_regs : register list;
+ c_free_regs : register list;
}
let env_push n e =
@@ -46,6 +49,7 @@ let env_push n e =
c_ret_lbl = e.c_ret_lbl;
c_need_fp = e.c_need_fp;
c_fp_used = kk;
+ c_free_regs = e.c_free_regs;
c_save_regs = e.c_save_regs }, -kk
let env_add_var vid vv e =
@@ -54,9 +58,21 @@ let env_add_var vid vv e =
c_ret_ref = e.c_ret_ref;
c_ret_lbl = e.c_ret_lbl;
c_save_regs = e.c_save_regs;
+ c_free_regs = e.c_free_regs;
c_fp_used = e.c_fp_used;
c_need_fp = e.c_need_fp; }
+let env_get_free_reg e =
+ let r, more = List.hd e.c_free_regs, List.tl e.c_free_regs in
+ { c_penv = e.c_penv;
+ c_names = e.c_names;
+ c_ret_ref = e.c_ret_ref;
+ c_ret_lbl = e.c_ret_lbl;
+ c_need_fp = e.c_need_fp;
+ c_fp_used = e.c_fp_used;
+ c_free_regs = more;
+ c_save_regs = r::e.c_save_regs }, r
+
let globals_env = ref Smap.empty
(* Chaînes de caractères utilisées dans le programme *)
@@ -132,6 +148,7 @@ type expr_type =
let cla r a = match a with
| Addr -> nop
| AddrByReg(x, rg) -> la r areg (x, rg)
+ | Value r -> raise (Reference_register r)
| _ -> assert false
let cr r a = match a with (* conditionnally read *)
| Addr -> lw r areg (0, r)
@@ -142,7 +159,6 @@ let crb r q a = match a with
| Value k -> q, k
| _ -> q ++ cr r a, r
-let use_regs = [ v0; v1; t0; t1; t2; t3; t4; t5; t6; t7; t8; t9 ]
let spare_reg = s0
let spare_reg2 = s1
@@ -171,6 +187,7 @@ let saver env save_regs =
c_ret_lbl = env.c_ret_lbl;
c_fp_used = new_fp_used;
c_need_fp = env.c_need_fp;
+ c_free_regs = env.c_free_regs;
c_save_regs = (List.filter (fun k -> k <> r) env.c_save_regs) }
)
(nop, nop, env) save_regs
@@ -259,7 +276,8 @@ let rec gen_expr env free_regs save_regs e =
| Value r -> t, AddrByReg (0, r)
| _ -> t ++ cr r a, Addr
end
- | Ast.Ref -> t ++ cla r a, Copy
+ | Ast.Ref ->
+ t ++ cla r a, 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
@@ -365,7 +383,7 @@ and code_for_args env arg_list regs =
let args_in_stack = List.rev args_in_stack in
let code_for_stack, _ = List.fold_left
(fun (code, u) (arg, byref) ->
- let c, addr = gen_expr kenv use_regs [] arg in
+ let c, addr = gen_expr kenv (v0::kenv.c_free_regs) [] arg in
(if byref then
c ++ cla v0 addr ++ sw v0 areg (-kenv.c_fp_used + u, fp) ++ code, u+4
else
@@ -379,7 +397,7 @@ and code_for_args env arg_list regs =
let rec mk_code_callz e = function
| [] -> nop
| (reg, (expr, byref))::more_args ->
- let c, addr = gen_expr e (reg::use_regs) [] expr in
+ let c, addr = gen_expr e (reg::kenv.c_free_regs) [] expr in
if more_args = [] then
c ++ (if byref then cla reg addr else cr reg addr)
else
@@ -395,7 +413,7 @@ and code_for_args env arg_list regs =
let code_reg_dont_call, _ =
List.fold_left
(fun (code, ur) (reg, (expr, byref)) ->
- let c, addr = gen_expr kenv (reg::use_regs) ur expr in
+ let c, addr = gen_expr kenv (reg::kenv.c_free_regs) ur expr in
code ++ c ++ (if byref then cla reg addr else cr reg addr), reg::ur)
(nop, []) arg_reg_dont_call
in
@@ -403,34 +421,34 @@ and code_for_args env arg_list regs =
in code, (List.map fst args_in_regs), kenv
-let gen_expr_v0 env = gen_expr env use_regs env.c_save_regs
-
+let gen_expr_dr dr env = gen_expr env (dr::env.c_free_regs) env.c_save_regs
+let gen_expr_v0 = gen_expr_dr v0
-let rec gen_stmt env = function
- | TSEmpty -> nop, nop, env
+let rec gen_stmt alloc_vars_in_regs env = function
+ | TSEmpty -> nop, env
| TSExpr(e) ->
- comment "expr" ++ (fst (gen_expr_v0 env e)), nop, env
+ comment "expr" ++ (fst (gen_expr_v0 env e)), env
| TSIf(cond, s1, s2) ->
let c, a = gen_expr_v0 env cond in
let c, reg = crb v0 c a in
let l_else = id "_cond_else" 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
+ let c_then = gen_block env [s1] in
+ let c_else = gen_block env [s2] in
comment "if"
++ c ++ beqz reg l_else
++ c_then ++ b l_end
++ label l_else ++ c_else
- ++ label l_end, d_then ++ d_else, env
+ ++ label l_end, env
| TSWhile(cond, body) ->
let c, a = gen_expr_v0 env cond in
let c, reg = crb v0 c a 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
+ let c_body = gen_block env [body] in
comment "while" ++ b l_cond
++ label l_begin ++ c_body
- ++ label l_cond ++ c ++ bnez reg l_begin, d_body, env
+ ++ label l_cond ++ c ++ bnez reg l_begin, env
| TSFor(before, cond, after, body) ->
let l_begin = id "_for_begin" in
let l_cond = id "_for_cond" in
@@ -444,38 +462,44 @@ let rec gen_stmt env = function
let c, a = gen_expr_v0 env x in
let c, reg = crb v0 c a in
c ++ bnez reg l_begin in
- let c_body, d_body, _ = gen_stmt env body in
+ let c_body = gen_block 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
+ ++ label l_cond ++ c_cond, env
| TSBlock(b) ->
- let c, d = gen_block env b in
- comment "block" ++ c, d, env
+ let c = gen_block env b in
+ comment "block" ++ c, env
| TSReturn (None) ->
- comment "return" ++ b env.c_ret_lbl, nop, env
+ comment "return" ++ b env.c_ret_lbl, env
| TSReturn (Some e) ->
let c, a = gen_expr_v0 env e in
comment "return"
++ c ++ (if env.c_ret_ref then cla v0 a else cr v0 a)
- ++ b env.c_ret_lbl, nop, env
+ ++ b env.c_ret_lbl, env
| TSDeclare (ty, id) ->
- let s = type_size env.c_penv ty in
- let env2, pos = env_push s env in
- let code = match ty with
- | TClass(i) ->
- 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
- let code_save_regs, code_restore_regs, env_regs_saved = saver env2 env.c_save_regs in
- code_save_regs
- ++ la a0 areg (pos, fp)
- ++ la sp areg (-env_regs_saved.c_fp_used, fp) ++ jal cproto.tp_unique_ident
- ++ code_restore_regs
- | _ -> sw zero areg (pos, fp)
- in
- comment ("declare " ^ id) ++ code, nop,
- env_add_var id (VStack pos) env2
+ if num ty && alloc_vars_in_regs && List.length env.c_free_regs > 5 then
+ (* allocate variable in register *)
+ let env2, reg = env_get_free_reg env in
+ comment ("declare " ^ id) ++ move reg zero,
+ env_add_var id (VRegister reg) env2
+ else
+ let s = type_size env.c_penv ty in
+ let env2, pos = env_push s env in
+ let code = match ty with
+ | TClass(i) ->
+ 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
+ let code_save_regs, code_restore_regs, env_regs_saved = saver env2 env.c_save_regs in
+ code_save_regs
+ ++ la a0 areg (pos, fp)
+ ++ la sp areg (-env_regs_saved.c_fp_used, fp) ++ jal cproto.tp_unique_ident
+ ++ code_restore_regs
+ | _ -> sw zero areg (pos, fp)
+ in
+ comment ("declare " ^ id) ++ code,
+ env_add_var id (VStack pos) env2
| TSDeclareAssignConstructor(cls, id, constr, args) ->
let env2, pos = env_push cls.tc_size env in
let code =
@@ -486,49 +510,63 @@ let rec gen_stmt env = function
++ la sp areg (-env_args.c_fp_used, fp) ++ jal constr
++ code_restore_regs
in
- comment ("declare " ^ id) ++ code, nop,
+ comment ("declare " ^ id) ++ code,
env_add_var id (VStack pos) env2
| TSDeclareAssignExpr ((ty, ref), id, e) ->
- let s = if ref then 4 else type_size env.c_penv ty in
- assert (s = 4);
- let env2, pos = env_push 4 env in
- let code, a = gen_expr_v0 env e in
- comment ("declare " ^ id)
- ++ (if ref then
- code ++ cla v0 a ++ sw v0 areg (pos, fp)
- else
- let k, b = crb v0 code a in
- k ++ sw b areg (pos, fp)
- ), nop,
- env_add_var id (if ref then VStackByRef pos else VStack pos) env2
+ assert (ref || num ty);
+ if alloc_vars_in_regs && List.length env.c_free_regs > 5 then
+ (* allocate variable in register *)
+ let env2, reg = env_get_free_reg env in
+ let code, a = gen_expr env (reg::env2.c_free_regs) env.c_save_regs e in
+ comment ("declare " ^ id)
+ ++ code ++ (if ref then cla reg a else cr reg a),
+ env_add_var id (if ref then VRegisterByRef reg else VRegister reg) env2
+ else
+ let code, a = gen_expr_v0 env e in
+ let env2, pos = env_push 4 env in
+ comment ("declare " ^ id)
+ ++ (if ref then
+ code ++ cla v0 a ++ sw v0 areg (pos, fp)
+ else
+ let k, b = crb v0 code a in
+ k ++ sw b areg (pos, fp)
+ ),
+ env_add_var id (if ref then VStackByRef pos else VStack pos) env2
| TSWriteCout(sl) ->
let save_code, restore_code, env2 = saver env
(if List.mem a0 env.c_save_regs then [a0] else []) in
- let text1, data1 = List.fold_left
- (fun (text, data) -> function
+ let text1 = List.fold_left
+ (fun text -> function
| TSEExpr(e) ->
- let t, a = gen_expr env2 (a0::use_regs) (env2.c_save_regs) e in
- text ++ t ++ cr a0 a ++ li v0 1 ++ syscall, data
+ let t, a = gen_expr_dr a0 env2 e in
+ text ++ t ++ cr a0 a ++ li v0 1 ++ syscall
| TSEStr(s) ->
- let l, d =
+ let l =
if Hashtbl.mem strings s then
- Hashtbl.find strings s, nop
+ Hashtbl.find strings s
else
let l = id "_s" in Hashtbl.add strings s l;
- l, label l ++ asciiz s
+ l
in
- text ++ la a0 alab l ++ li v0 4 ++ syscall, data ++ d)
- (nop, nop) sl in
+ text ++ la a0 alab l ++ li v0 4 ++ syscall)
+ nop sl in
comment "cout<<..."
- ++ save_code ++ text1 ++ restore_code, data1, env
+ ++ save_code ++ text1 ++ restore_code, env
and gen_block env b =
- let text, data, fin_env =
- List.fold_left (fun (t, d, e) s ->
- let tt, dd, ee = gen_stmt e s in
- t ++ tt, d ++ dd, ee)
- (nop, nop, env) b
+ let rec fold env = function
+ | [] -> nop
+ | stmt::next ->
+ let does_call_after = List.exists stmt_does_call next in
+ try
+ let tt, ee = gen_stmt (not does_call_after) env stmt in
+ let more_code = fold ee next in
+ tt ++ more_code
+ with Reference_register _ ->
+ let tt, ee = gen_stmt false env stmt in
+ let more_code = fold ee next in
+ tt ++ more_code
in
- text, data
+ fold env b
let gen_decl tenv decl = match decl with
| TDGlobal(ty, id) ->
@@ -558,6 +596,7 @@ let gen_decl tenv decl = match decl with
c_ret_lbl = "_return_" ^ proto.tp_unique_ident;
c_fp_used = 8;
c_need_fp = need_fp;
+ c_free_regs = [ t0; t1; t2; t3; t4; t5; t6; t7; t8; t9; v1 ];
c_save_regs = List.filter (fun r -> not (List.mem r free_regs)) [a0; a1; a2; a3];
} in
let code_for_constructor, does_calls = match proto.tp_ret_type with
@@ -575,19 +614,26 @@ let gen_decl tenv decl = match decl with
let save_code, unsave_code, env2 =
saver env (List.filter (fun x -> x <> a0 || proto.tp_class = None) env.c_save_regs)
in
- let text, data = gen_block env2 block in
+ let text = gen_block env2 block in
label proto.tp_unique_ident
++ sw fp areg (-4, sp) ++ sw ra areg (-8, sp) ++ move fp sp
++ code_for_virtual ++ save_code ++ code_for_constructor ++ text
++ label env.c_ret_lbl ++ move sp fp ++ lw fp areg (-4, sp) ++ lw ra areg (-8, sp)
- ++ jr ra, data
+ ++ jr ra, nop
else
- let text, data = gen_block env block in
+ let rec bb_fp e =
+ try
+ gen_block e block
+ with Reference_register r ->
+ let save_code, _, env2 = saver env [r] in
+ save_code ++ bb_fp env2
+ in
+ let text = bb_fp env in
label proto.tp_unique_ident
++ (if !need_fp then sw fp areg (-4, sp) ++ move fp sp else nop)
++ code_for_virtual ++ text
++ label env.c_ret_lbl ++ (if !need_fp then move sp fp ++ lw fp areg (-4, sp) else nop)
- ++ jr ra, data
+ ++ jr ra, nop
| TDClass(c) ->
let constructor_calls_something = ref false in
(* Call default constructor of parent classes *)
@@ -667,8 +713,11 @@ let generate p =
++ li v0 10 ++ syscall
++ label "_nothing" ++ jr ra
++ text in
+ let str = Hashtbl.fold
+ (fun str lbl data -> data ++ label lbl ++ asciiz str)
+ strings nop in
{ text = text;
- data = data }
+ data = data ++ str }
with
| Assert_failure (k, a, b) -> raise (Very_bad_error (
"(unexpected) Assertion failure: "^k^" at "^(string_of_int a)^":"^(string_of_int b)))