add substraction and division

baselib.ml

@@ -6,7 +6,9 @@ let _types_ =
   Env.of_seq
     (List.to_seq
        [ "%add", Func_t (Int_t, [ Int_t; Int_t ])
+       ; "%sub", Func_t (Int_t, [ Int_t; Int_t ])
        ; "%mul", Func_t (Int_t, [ Int_t; Int_t ])
+       ; "%div", Func_t (Int_t, [ Int_t; Int_t ])
        ])
 ;;
 
@@ -15,6 +17,8 @@ let builtins =
     (fun env (fn, impl) -> Env.add fn impl env)
     Env.empty
     [ "%add", [ Lw (T0, Mem (SP, 0)); Lw (T1, Mem (SP, 4)); Add (V0, T0, T1) ]
+    ; "%sub", [ Lw (T0, Mem (SP, 0)); Lw (T1, Mem (SP, 4)); Sub (V0, T0, T1) ]
     ; "%mul", [ Lw (T0, Mem (SP, 0)); Lw (T1, Mem (SP, 4)); Mul (V0, T0, T1) ]
+    ; "%div", [ Lw (T0, Mem (SP, 0)); Lw (T1, Mem (SP, 4)); Div (V0, T1, T0) ]
     ]
 ;;

lexer.mll

@@ -22,7 +22,9 @@ rule token = parse
 | '='           { Lassign }
 | ';'           { Lsc }
 | '+'           { Ladd }
+| '-'           { Lsub }
 | '*'           { Lmul }
+| '/'           { Ldiv }
 | ident as i    { Lvar i }
 | '#'           { comment lexbuf }
 | _ as c        { raise (Error c) }

mips.ml

@@ -48,6 +48,8 @@ type instr =
   | Addi of reg * reg * int
   | Add of reg * reg * reg
   | Mul of reg * reg * reg
+  | Sub of reg * reg * reg
+  | Div of reg * reg * reg
   | Syscall
   | B of label
   | Beqz of reg * label
@@ -127,6 +129,10 @@ let fmt_instr = function
     Printf.sprintf "  add %s, %s, %s" (fmt_reg rd) (fmt_reg rs) (fmt_reg rt)
   | Mul (rd, rs, rt) ->
     Printf.sprintf "  mul %s, %s, %s" (fmt_reg rd) (fmt_reg rs) (fmt_reg rt)
+  | Sub (rd, rs, rt) ->
+    Printf.sprintf "  sub %s, %s, %s" (fmt_reg rd) (fmt_reg rs) (fmt_reg rt)
+  | Div (rd, rs, rt) ->
+    Printf.sprintf "  div %s, %s, %s" (fmt_reg rd) (fmt_reg rs) (fmt_reg rt)
   | Syscall -> Printf.sprintf "  syscall"
   | B l -> Printf.sprintf "  b %s" l
   | Beqz (r, l) -> Printf.sprintf "  beqz %s, %s" (fmt_reg r) l

parser.mly

@@ -8,9 +8,9 @@
 %token <Ast.type_t> Ltype
 %token <string> Lvar
 %token Lend Lassign Lsc Lreturn
-%token Ladd Lmul
+%token Ladd Lsub Lmul Ldiv
 
-%left Ladd Lmul
+%left Ladd Lsub Lmul Ldiv
 
 %start prog
 
@@ -49,7 +49,13 @@ expr:
   | a = expr ; Ladd ; b = expr {
     Call { func = "%add" ; args = [ a ; b ] ; pos = $startpos($2) }
   }
+  | a = expr ; Lsub ; b = expr {
+    Call { func = "%sub" ; args = [ a ; b ] ; pos = $startpos($2) }
+  }
   | a = expr ; Lmul ; b = expr {
     Call { func = "%mul" ; args = [ a ; b ] ; pos = $startpos($2) }
   }
+  | a = expr ; Ldiv ; b = expr {
+    Call { func = "%div" ; args = [ a ; b ] ; pos = $startpos($2) }
+  }
 ;

tests/10_math.test

@@ -1 +1,2 @@
 int res = 13 * 100 + 12;
+res = res * 2 / 2;