Vortex 2.0 changes:

+ Microarchitecture optimizations
+ 64-bit support
+ Xilinx FPGA support
+ LLVM-16 support
+ Refactoring and quality control fixes

hw/rtl/libs/VX_lzc.sv

@@ -1,31 +1,55 @@
+// Copyright © 2019-2023
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 `include "VX_platform.vh"
 
 `TRACING_OFF
 module VX_lzc #(
-    parameter N    = 2,
-    parameter MODE = 0, // 0 -> trailing zero, 1 -> leading zero
-    parameter LOGN = $clog2(N)
+    parameter N       = 2,
+    parameter REVERSE = 0,  // 0 -> leading zero, 1 -> trailing zero,
+    parameter LOGN    = `LOG2UP(N)
 ) (
-    input  wire [N-1:0]    in_i,
-    output wire [LOGN-1:0] cnt_o,
-    output wire            valid_o
+    input  wire [N-1:0]    data_in,
+    output wire [LOGN-1:0] data_out,
+    output wire            valid_out
 );
-    wire [N-1:0][LOGN-1:0] indices;
+    if (N == 1) begin
+
+        `UNUSED_PARAM (REVERSE)
+
+        assign data_out  = '0;
+        assign valid_out = data_in;
+
+    end else begin
+
+        wire [N-1:0][LOGN-1:0] indices;
+
+        for (genvar i = 0; i < N; ++i) begin
+            assign indices[i] = REVERSE ? LOGN'(i) : LOGN'(N-1-i);
+        end
+
+        VX_find_first #(
+            .N       (N),
+            .DATAW   (LOGN),
+            .REVERSE (!REVERSE)
+        ) find_first (        
+            .data_in   (indices),
+            .valid_in  (data_in),
+            .data_out  (data_out),
+            .valid_out (valid_out)
+        );
 
-    for (genvar i = 0; i < N; ++i) begin
-        assign indices[i] = MODE ? LOGN'(N-1-i) : LOGN'(i);
     end
-
-    VX_find_first #(
-        .N       (N),
-        .DATAW   (LOGN),
-        .REVERSE (MODE)
-    ) find_first (        
-        .data_i  (indices),
-        .valid_i (in_i),
-        .data_o  (cnt_o),
-        .valid_o (valid_o)
-    );
   
 endmodule
-`TRACING_ON
+`TRACING_ON