What you are doing is *compiler* dependant, not *platform* dependant. You might
want to check for compiler-specific conditionals instead.
Or avoid the whole problem and just do it by hand, as Al Cilcius suggests. It's
uglier, but more portable.
-- Keith
"Mike Margerum" <[EMAIL PROTECTED]> on 05/19/2000 01:26:04 PM
Please respond to "Palm Developer Forum" <[EMAIL PROTECTED]>
Sent by: "Mike Margerum" <[EMAIL PROTECTED]>
To: "Palm Developer Forum" <[EMAIL PROTECTED]>
cc: (Keith Rollin/HQ/3Com)
Subject: Re: Bit packing and endianess
I just conditionally compile the struct based on whether its for windows or
the palm:
#ifdef WIN32
typedef struct {
Word day :5;
Word month :4;
Word year :7;
} DateType;
#else
typedef struct {
Word year :7;
Word month :4;
Word day :5;
} DateType;
#endif
----- Original Message -----
From: "Chris Faherty" <[EMAIL PROTECTED]>
To: "Palm Developer Forum" <[EMAIL PROTECTED]>
Sent: Friday, May 19, 2000 3:51 PM
Subject: Bit packing and endianess
> I'm porting some of my palmos code over to a little-endian device
(RIM950).
> It uses the MS Visual C++ compiler for the SDK. The problem I am having
is
> with structures that use bit packing:
>
> typedef struct {
> Word year :7;
> Word month :4;
> Word day :5;
> } DateType;
>
> On Codewarrior and GCC the bits are packed starting with msb. In VC++
they
> start at lsb. So in VC++ I have to use:
>
> typedef struct {
> Word day :5;
> Word month :4;
> Word year :7;
> } DateType;
>
> I realize that Word (an unsigned short) is LSB versus MSB and though I
> already take that into account, the position of the bit components is
> opposite. For example on the palm compilers year is the most significant
7
> bits of the Word, but in VC++ (using the top structure) year is the least
> significant 7 bits.
>
> Just wondering if there is a compiler directive to tell VC++ to pack those
> bits starting at the msb. It doesn't really seem like an endianess issue
but
> rather a compiler preference issue.
>
>
> /* Chris Faherty <[EMAIL PROTECTED]> */
> /* Your Stock has crashed - you must now restart your system */
>
>
> --
> For information on using the Palm Developer Forums, or to unsubscribe,
please see http://www.palmos.com/dev/tech/support/forums/
>
>
--
For information on using the Palm Developer Forums, or to unsubscribe, please
see http://www.palmos.com/dev/tech/support/forums/
--
For information on using the Palm Developer Forums, or to unsubscribe, please see
http://www.palmos.com/dev/tech/support/forums/
