FPU float<->int conversion optimization

hw/rtl/libs/VX_lzc.v

@@ -0,0 +1,27 @@
+`include "VX_platform.vh"
+
+module VX_lzc #(
+    parameter DATAW  = 1,
+    parameter LDATAW = `LOG2UP(DATAW)
+) (
+    input wire  [DATAW-1:0]  data_in,
+    output wire [LDATAW-1:0] data_out,
+    output wire              valid_out
+); 
+
+    reg [LDATAW-1:0] data_out_r;
+
+    always @(*) begin
+        data_out_r = 'x;
+        for (integer i = DATAW-1; i >= 0; --i) begin
+            if (data_in[i]) begin
+                data_out_r = LDATAW'(DATAW-1-i);
+                break;
+            end
+        end
+    end
+
+    assign data_out  = data_out_r;
+    assign valid_out = (| data_in);
+  
+endmodule