考虑以下 SystemC 代码:
#include <iostream>
#include "systemc.h"
using namespace std;
int
sc_main(int argc, char* argv[])
{
sc_bv<3> foo;
operand_0 = "0d6";
cout << foo.to_long() << endl; // prints -2
return EXIT_SUCCESS;
}
如我所料,这会打印出 -2 而不是 6。这样做的明显原因是 to_long() 将位向量 0b110 解释为有符号。但是,在IEEE Std 1666-2011中,它在第 7.2.9 节中提到了整数转换函数,例如 to_long():
These member functions shall interpret the bits within a SystemC integer,
fixed-point type or vector, or any part-select or concatenation thereof,
as representing an unsigned binary value, with the exception of signed
integers and signed fixed-point types.
我是否误解了某些东西,或者 Accellera 的 SystemC 实现在这方面没有遵守标准?