hw: Add VFCVT(U).D.S instructions (#170)

Author: alex96295

hw/snitch/src/riscv_instr.sv

@@ -703,6 +703,8 @@ package riscv_instr;
   localparam logic [31:0] VFCPKB_B_D         = 32'b1011010??????????111?????0110011;
   localparam logic [31:0] VFCPKC_B_D         = 32'b1011011??????????011?????0110011;
   localparam logic [31:0] VFCPKD_B_D         = 32'b1011011??????????111?????0110011;
+  localparam logic [31:0] VFCVT_D_S          = 32'b100110000100?????001?????0110011;
+  localparam logic [31:0] VFCVTU_D_S         = 32'b100110000100?????101?????0110011;
   localparam logic [31:0] VFCVT_S_B          = 32'b100110000111?????000?????0110011;
   localparam logic [31:0] VFCVTU_S_B         = 32'b100110000111?????100?????0110011;
   localparam logic [31:0] VFCVT_B_S          = 32'b100110000100?????011?????0110011;

hw/snitch/src/snitch.sv

@@ -1349,6 +1349,19 @@ module snitch import snitch_pkg::*; import riscv_instr::*; #(
           illegal_inst = 1'b1;
         end
       end
+      VFCVT_D_S,
+      VFCVTU_D_S: begin
+        if (FP_EN && XFVEC && RVF && FLEN >= 32) begin
+          if (RVF && RVD) begin
+            write_rd = 1'b0;
+            acc_qvalid_o = valid_instr;
+          end else begin
+            illegal_inst = 1'b1;
+          end
+        end else begin
+          illegal_inst = 1'b1;
+        end
+      end
       VFCPKA_H_S,
       VFCPKB_H_S,
       VFCVT_H_S,

hw/snitch_cluster/src/snitch_fp_ss.sv

@@ -561,6 +561,16 @@ module snitch_fp_ss import snitch_pkg::*; #(
         vectorial_op = 1'b1;
         set_dyn_rm   = 1'b1;
       end
+      riscv_instr::VFCVT_D_S,
+      riscv_instr::VFCVTU_D_S: begin
+        fpu_op = fpnew_pkg::F2F;
+        op_select[0] = RegA;
+        src_fmt      = fpnew_pkg::FP32;
+        dst_fmt      = fpnew_pkg::FP64;
+        vectorial_op = 1'b1;
+        set_dyn_rm   = 1'b1;
+        if (acc_req_q.data_op inside {riscv_instr::VFCVTU_D_S}) op_mode = 1'b1;
+      end
       // Double Precision
       riscv_instr::FADD_D: begin
         fpu_op = fpnew_pkg::ADD;