scoreboard: size improvements

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

src/scoreboard.sv

@@ -86,8 +86,7 @@ module scoreboard #(
   logic [NR_ENTRIES-1:0] flushed;
   logic [$clog2(NR_ENTRIES)-1:0] num_flush;
 
-  logic [NR_ENTRIES-1:0] has_mem_access_n, has_mem_access_q;
-  logic [NR_ENTRIES-1:0] is_cf_n, is_cf_q;
+  logic [NR_ENTRIES-1:0] is_cf, has_mem_access;
 
   // the issue queue is full don't issue any new instructions
   // works since aligned to power of 2
@@ -104,8 +103,17 @@ module scoreboard #(
   end
 
   // check instructions in the scoreboard for memory operations and ctrl flow
-  assign has_mem_access_o = (|has_mem_access_q);
-  assign has_control_flow_o = (|is_cf_q);
+  for (genvar i = 0; i < NR_ENTRIES; i++) begin
+      assign is_cf[i] = mem_q[i].issued && ~mem_q[i].sbe.valid &&
+                        mem_q[i].sbe.fu == ariane_pkg::CTRL_FLOW &&
+                        mem_q[i].sbe.op != ariane_pkg::ADD;
+      assign has_mem_access[i] = (mem_q[i].issued && ~mem_q[i].sbe.valid &&
+                                  mem_q[i].sbe.fu inside {ariane_pkg::LOAD, ariane_pkg::STORE}) ||
+                                 mem_q[i].sbe.valid && mem_q[i].sbe.fu == ariane_pkg::STORE;
+  end
+
+  assign has_control_flow_o = |is_cf;
+  assign has_mem_access_o = |has_mem_access;
 
   // maintain a FIFO with issued instructions
   // keep track of all issued instructions
@@ -113,9 +121,6 @@ module scoreboard #(
     // default assignment
     mem_n    = mem_q;
     issue_en = 1'b0;
-    has_mem_access_n = has_mem_access_q;
-    is_cf_n = is_cf_q;
-    decoded_instr_ack_o = 1'b0;
     flushed = '0;
 
     decoded_instr_ack_o = decoded_instr_valid_i && ~issue_full;
@@ -125,14 +130,11 @@ module scoreboard #(
       // the decoded instruction we put in there is valid (1st bit)
       // increase the issue counter and advance issue pointer
       issue_en = 1'b1;
-      // decoded_instr_ack_o = 1'b1;
       mem_n[write_pointer_q] = {1'b1,
                                 1'b1,                                      // valid bit
                                 ariane_pkg::is_rd_fpr(decoded_instr_i.op), // whether rd goes to the fpr
                                 decoded_instr_i                            // decoded instruction record
                                 };
-      has_mem_access_n[write_pointer_q] = decoded_instr_i.fu inside {ariane_pkg::LOAD, ariane_pkg::STORE};
-      is_cf_n[write_pointer_q] = decoded_instr_i.fu == ariane_pkg::CTRL_FLOW && decoded_instr_i.op != ariane_pkg::ADD;
     end
 
     issue_instr_o = mem_n[issue_pointer_q];
@@ -149,8 +151,6 @@ module scoreboard #(
           mem_n[i].pending = 1'b0;
           mem_n[i].issued = 1'b0;
           flushed[i] = 1'b1;
-          has_mem_access_n[i] = 1'b0;
-          is_cf_n[i] = 1'b0;
         end
       end
     end
@@ -181,11 +181,6 @@ module scoreboard #(
         // write the fflags back from the FPU (exception valid is never set), leave tval intact
         else if (mem_q[trans_id_i[i]].sbe.fu inside {ariane_pkg::FPU, ariane_pkg::FPU_VEC})
           mem_n[trans_id_i[i]].sbe.ex.cause = ex_i[i].cause;
-
-        if (mem_q[trans_id_i[i]].sbe.fu != ariane_pkg::STORE)
-          has_mem_access_n[trans_id_i[i]] = 1'b0;
-
-        is_cf_n[trans_id_i[i]] = 1'b0;
       end
     end
 
@@ -199,8 +194,6 @@ module scoreboard #(
         mem_n[commit_pointer_q[i]].pending   = 1'b0;
         mem_n[commit_pointer_q[i]].issued    = 1'b0;
         mem_n[commit_pointer_q[i]].sbe.valid = 1'b0;
-        has_mem_access_n[commit_pointer_q[i]] = 1'b0;
-        is_cf_n[commit_pointer_q[i]] = 1'b0;
       end
     end
 
@@ -214,8 +207,6 @@ module scoreboard #(
         mem_n[i].issued       = 1'b0;
         mem_n[i].sbe.valid    = 1'b0;
         mem_n[i].sbe.ex.valid = 1'b0;
-        has_mem_access_n[i]   = 1'b0;
-        is_cf_n[i]            = 1'b0;
       end
     end
   end
@@ -360,16 +351,12 @@ module scoreboard #(
       commit_pointer_q <= '0;
       issue_pointer_q  <= '0;
       write_pointer_q  <= '0;
-      has_mem_access_q <= '0;
-      is_cf_q          <= '0;
     end else begin
       issue_cnt_q      <= issue_cnt_n;
       issue_pointer_q  <= issue_pointer_n;
       write_pointer_q  <= write_pointer_n;
       mem_q            <= mem_n;
       commit_pointer_q <= commit_pointer_n;
-      has_mem_access_q <= has_mem_access_n;
-      is_cf_q          <= is_cf_n;
     end
   end