Left shift with zero results in

[katang]

In my program, I have a member variable

    sc_dt::sc_uint<MASK_WIDTH>
  mymask; ///< One-hot bitmask corresponding to ID 

In my constructor, I can initialize that variable like

  mymask(ID ? 1 << ID : 1)

because using only

mymask(1 << ID )

SC library results in

 

Error: (E5) out of bounds: sc_uint[_base] initialization: length = -2147483648 violates 1 <= length <= 64

In file: ../../../../src/sysc/datatypes/int/sc_uint_base.cpp:342

 I see nothing against shifting a value by zero position. Is there any deeper reason?

 

[Philipp A Hartmann]

Shifting by zero should of course be supported. Can you provide a self-contained example demonstrating the problem?

Instead, the error message indicates, that you try to create an sc_uint<-2147483648> (or rather an sc_uint_base with the dynamic width of this value, e.g.), which is not allowed.

• What's the definition of MASK_WIDTH?
• What's the definition of ID?

Hope that helps,
  Philipp

[katang]

In a config file, I have

#define CORE_BUS_WIDTH 5

In my SC_MODULE I have

//    sc_dt::sc_uint<CORE_BUS_WIDTH>
    int
  mID; ///< internal ID (sequence number) of the core

Changing the data type from int to sc_unit provokes the error message, with all others unchanged.

Works also with line

sc_dt::sc_uint<5>

 

[Philipp A Hartmann]

Can you please post a complete, self-contained example to demonstrate the issue?  Reading your post, I still cannot infer what actual values, types, ... are involved and not even where you changed the "line" to sc_uint<5>.

The following code works for me:

#include <systemc>

int sc_main (int, char *[]) {

   using namespace sc_dt;

   #define CORE_BUS_WIDTH 5
   #define MASK_WIDTH 32
   {
     sc_uint<CORE_BUS_WIDTH> id;
     sc_uint<MASK_WIDTH>     mask(1 << id);
     std::cout << "id=" << id << "\t- mask=" << mask.to_string(SC_BIN) << std::endl;
   }
   {
     sc_uint<CORE_BUS_WIDTH> id(-1);
     sc_uint<MASK_WIDTH>     mask(1 << id);
     std::cout << "id=" << id << "\t- mask=" << mask.to_string(SC_BIN) << std::endl;
   }
   return 0;
}

From your original error message, it looks more like an issue with MASK_WIDTH or CORE_BUS_WIDTH to me.

Do you see any compiler warnings?

Hope that helps,
 Philipp

[katang]

Sorry for bothering you. I named it as MASK_WIDTH and set it as MASK_MAXIMUM_VALUE.

Later I believed to myself that the definition was really a width.