Clean up ALU before merge

Co-authored-by: Warrick Lo <wlo@warricklo.net>
Signed-off-by: Warrick Lo <wlo@warricklo.net>

1 files changed, 18 insertions, 29 deletions

diff --git a/rtl/alu.sv b/rtl/alu.sv
index 30645c1..2966135 100644
--- a/rtl/alu.sv
+++ b/rtl/alu.sv
@@ -1,6 +1,8 @@
-module alu
-  import montreal_pkg::*;
-#(
+/* SPDX-License-Identifier: CERN-OHL-P-2.0 */
+
+`include "types.svh"
+
+module alu #(
   parameter int unsigned XLEN        = config_pkg::XLEN,
   parameter int unsigned SLICE_WIDTH = config_pkg::SLICE_WIDTH,
 
@@ -27,48 +29,35 @@ module alu
   /* Carry signals. */
   logic carry, carry_d, carry_q;
 
-  /* Adder width is SLICE_WIDTH + 1 to account for carry-out. */
-  logic [SLICE_WIDTH:0] adder_a, adder_b, adder_result;
-
-  /* For the first slice, carry-in must be driven to zero for addition 
-   * and one for subtraction or comparisons. All other slices use the 
+  /* For the first slice, carry-in must be driven to zero for addition
+   * and one for subtraction or comparisons. All other slices use the
    * carry-out from the previous slice */
+  assign carry = (count_i == '0) ? negate_b : carry_q;
 
-  assign carry   = (count_i == '0) ? negate_b : carry_q;
+  /* Adder width is SLICE_WIDTH + 1 to account for carry-out. */
+  logic [SLICE_WIDTH:0] adder_a, adder_b, adder_result;
 
-  /* ADD, SUB, SLT, SLTU use the same adder to computer their results*/
-  
   assign adder_a = {1'b0, a_i};
   assign adder_b = {1'b0, (b_i ^ {SLICE_WIDTH{negate_b}})};
+
+  /* ADD, SUB, SLT, SLTU use the same adder to computer their results*/
   assign adder_result = adder_a + adder_b + (SLICE_WIDTH + 1)'(carry);
+
   assign carry_o = adder_result[SLICE_WIDTH];
   assign carry_d = carry_o;
 
   /* Combinational arithmetic/logic core. */
   always_comb begin : alu_core
-    result_o = '0;
-
     unique casez (alu_op_i[2:0])
       /* ADD, SUB, SLT, SLTU. */
-      3'b0??: begin
-        result_o = adder_result[SLICE_WIDTH-1:0];
-      end
+      3'b0??: result_o = adder_result[SLICE_WIDTH-1:0];
       /* XOR. */
-      3'b100: begin 
-        result_o = a_i ^ b_i;
-        carry_d = 0; 
-      end
+      3'b100: result_o = a_i ^ b_i;
       /* OR. */
-      3'b110: begin
-        result_o = a_i | b_i;
-        carry_d = 0;
-      end
+      3'b110: result_o = a_i | b_i;
       /* AND. */
-      3'b111: begin 
-        result_o = a_i & b_i;
-        carry_d = 0;
-      end 
-      default: begin end
+      3'b111: result_o = a_i & b_i;
+      default: result_o = '0;
     endcase
   end : alu_core