frontend: remove usage of opaque module `unread'

Signed-off-by: Alban Gruin <alban.gruin@irit.fr>

src/frontend/bht.sv

@@ -34,8 +34,6 @@ module bht #(
     localparam ROW_ADDR_BITS = $clog2(ariane_pkg::INSTR_PER_FETCH);
     // number of bits we should use for prediction
     localparam PREDICTION_BITS = $clog2(NR_ROWS) + OFFSET + ROW_ADDR_BITS;
-    // we are not interested in all bits of the address
-    unread i_unread (.d_i(|vpc_i));
 
     struct packed {
         logic       valid;

src/frontend/btb.sv

@@ -36,8 +36,6 @@ module btb #(
     localparam PREDICTION_BITS = $clog2(NR_ROWS) + OFFSET + ROW_ADDR_BITS;
     // prevent aliasing to degrade performance
     localparam ANTIALIAS_BITS = 8;
-    // we are not interested in all bits of the address
-    unread i_unread (.d_i(|vpc_i));
 
     // typedef for all branch target entries
     // we may want to try to put a tag field that fills the rest of the PC in-order to mitigate aliasing effects

src/frontend/instr_queue.sv

@@ -374,12 +374,6 @@ module instr_queue (
     .pop_i      ( pop_address                  )
   );
 
-  unread i_unread_address_fifo (.d_i(|{empty_address, address_queue_usage}));
-  unread i_unread_branch_mask (.d_i(|branch_mask_extended));
-  unread i_unread_lzc (.d_i(|{branch_empty}));
-  unread i_unread_fifo_pos (.d_i(|fifo_pos_extended)); // we don't care about the lower signals
-  unread i_unread_instr_fifo (.d_i(|instr_queue_usage));
-
   always_ff @(posedge clk_i or negedge rst_ni) begin
     if (!rst_ni) begin
       idx_ds_q        <= 'b1;