code: public static int[] getParameterRegisters(Method obj) {
          Type[] argTypes = obj.getArgumentTypes();
          int[] regs = new int[argTypes.length];
  
          int curReg = obj.isStatic() ? 0 : 1;
          for (int t = 0; t < argTypes.length; t++) {
              String sig = argTypes[t].getSignature();
              regs[t] = curReg;
              curReg += SignatureUtils.getSignatureSize(sig);
          }
          return regs;
      }
docs: gets the set of registers used for parameters
  
  @param obj
  the context object for the method to find the parameter registers of
  
  @return the set of registers that parameters are using