Fix rs3 forwarding for cvxif

Author: flague

core/issue_read_operands.sv

@@ -185,6 +185,8 @@ module issue_read_operands
   logic [ CVA6Cfg.NrIssuePorts-1:0]                                rs3_raw_check;
   logic [ CVA6Cfg.NrIssuePorts-1:0]                                rs3_has_raw;
   logic [ CVA6Cfg.NrIssuePorts-1:0]                                rs3_fpr;
+  // CVXIF rs3 is a gpr and has to be accessed
+  logic [ CVA6Cfg.NrIssuePorts-1:0]                                rs3_gpr_cvxif;
 
 
   logic [CVA6Cfg.NR_SB_ENTRIES-1:0][ariane_pkg::REG_ADDR_SIZE-1:0] rd_list;
@@ -428,6 +430,8 @@ module issue_read_operands
     assign rs1_fpr[i] = (CVA6Cfg.FpPresent && ariane_pkg::is_rs1_fpr(issue_instr_i[i].op));
     assign rs2_fpr[i] = (CVA6Cfg.FpPresent && ariane_pkg::is_rs2_fpr(issue_instr_i[i].op));
     assign rs3_fpr[i] = (CVA6Cfg.FpPresent && ariane_pkg::is_imm_fpr(issue_instr_i[i].op));
+    assign rs3_gpr_cvxif[i] = CVA6Cfg.CvxifEn && (OPERANDS_PER_INSTR == 3)
+                          && issue_instr_i[i].fu == CVXIF;
   end
 
   // ----------------------------------
@@ -485,7 +489,7 @@ module issue_read_operands
         .idx_o(idx_hzd_rs3[i]),
         .valid_o(rs3_raw_check[i])
     );
-    assign rs3_has_raw[i] = rs3_raw_check[i] && rs3_fpr[i];
+    assign rs3_has_raw[i] = rs3_raw_check[i] && (rs3_fpr[i] || rs3_gpr_cvxif[i]);
   end
 
   // ----------------------------------
@@ -557,7 +561,7 @@ module issue_read_operands
         end
       end
 
-      if (rs3_has_raw[i] && rs3_fpr[i]) begin
+      if (rs3_has_raw[i]) begin
         if (rs3_valid[i]) begin
           forward_rs3[i] = 1'b1;
         end else begin  // the operand is not available -> stall