Re: Bus error after casting (well defined) const unsigned char * to const double *

[Martin Kaul]

Earl Purple wrote:
> g++ 3.4.2 (32 bit) on Solaris:
>
> I am passing doubles in binary format.
>
> So I receive the binary representation for a double (500000 in this
> particular case, which is 0x41 0x1e 0x84 0x80 0x00 0x00 0x00 0x00)
>
> If I reinterpret_cast the pointer to const double * then dereference it
> I get a Bus Error (core dumped).
>
> The workaround (that works) is to copy the buffer into a double, i.e.
> take a double, reinterpret_cast its address to unsigned char * and copy
> the buffer. That works, no crash.
>
> It worked fine until I compiled in release mode with O3 optimisation
> setting. -ffloat-store flag makes no difference.
hmm try to define the const double * as volatile

        volatile const double *d_ptr = ...;

Volatile variables not optimised by the compiler...

regards
  Martin