[prim_util_pkg] Fix DC warning in _clog2()
DC warns about assigning to an input port (`value`). Use an intermediate
variable instead.
```
Warning: ../src/lowrisc_prim_util_0.1/rtl/prim_util_pkg.sv:30: Port value of type input is being assigned. (VER-1005)
Warning: ../src/lowrisc_prim_util_0.1/rtl/prim_util_pkg.sv:32: Port value of type input is being assigned. (VER-1005)
```
Signed-off-by: Philipp Wagner <phw@lowrisc.org>
diff --git a/hw/ip/prim/rtl/prim_util_pkg.sv b/hw/ip/prim/rtl/prim_util_pkg.sv
index 6093646..36960c6 100644
--- a/hw/ip/prim/rtl/prim_util_pkg.sv
+++ b/hw/ip/prim/rtl/prim_util_pkg.sv
@@ -27,9 +27,12 @@
*/
function automatic integer _clog2(integer value);
integer result;
- value = value - 1;
- for (result = 0; value > 0; result = result + 1) begin
- value = value >> 1;
+ // Use an intermediate value to avoid assigning to an input port, which produces a warning in
+ // Synopsys DC.
+ integer v = value;
+ v = v - 1;
+ for (result = 0; v > 0; result++) begin
+ v = v >> 1;
end
return result;
endfunction
@@ -77,7 +80,7 @@
// to an implementation without a system function. Remove this workaround
// if we require a newer Xcelium version.
// See #2579 and #2597.
- return (value == 1) ? 1 : prim_util_pkg::_clog2(value);
+ return (value == 1) ? 1 : _clog2(value);
`else
return (value == 1) ? 1 : $clog2(value);
`endif
