add logical shift by shamt

cpu/src/alu/utils.mj

@@ -32,6 +32,21 @@ extand_const_n<n, offset>(c:[n]) = (o:[n + offset]) where
 end where
 
 
+shift_by_shamt_n<n, m, shift_val>(input:[n], shamt:[m], is_right, keep_sign) =
+																																(out:[n]) where
+	aux = mux(shamt[m-1],
+						mux(is_right,
+							extand_right_n<n - shift_val, shift_val>
+								(input[..(n-1) - shift_val], mux(keep_sign, input[0])),
+							extand_left_n<n - shift_val, shift_val>
+								(input[shift_val..])),
+						input);
+	out = shift_by_const_n<n, m-1, 2*m>(aux, shamt[..m-2], is_right, keep_sign);
+end where
+
+shift_by_shamt(input:[32], shamt:[5], is_right, keep_sign) = (out:[32]) where
+	out = shift_by_shamt_n<32, 5, 1>(input, shamt, is_right, keep_sign)
+end where
 
 (* ------------------------------------------------------------------------- *)
 (* Opérations booléennes *)
@@ -126,14 +141,12 @@ end where
 
 (* Fonction d'addition, qui fait la soustraction si le drapeau vaut 1 *)
 (* flag est le drapeau d'overflow, sub le drapeau de soustraction *)
-add_ALU(a:[32], b:[32], sub) = (o:[32], flag) where
+add_ALU(a:[32], b:[32], sub) = (o:[32]) where
 	(o, flag) = adder_n<32>(a, mux(sub, change_sign_n<32>(b), b), 0);
-	zero = equal_zero_n<32>(o);
 end where
 
-addi_ALU(a:[32], c:[16], sub) = (o:[32], flag) where
+addi_ALU(a:[32], c:[16], sub) = (o:[32]) where
     (o, flag) = add_ALU(a, extand_const_n<16,16>(c), sub);
-		zero = equal_zero_n<32>(o);
 end where
 
 (* Une fonction multiplication absolument peu pratique *)