Re: why some members in the struct lost after struct type compulsion transformation

On 7月15日, 下午8时32分, Manish <manishh.gu...@xxxxxxxxx> wrote:
On Jul 13, 6:02 pm, lje9292...@xxxxxxxxxxxx wrote:



On 7月12日, 下午11时53分, ganyong <ganyong2...@xxxxxxxxx> wrote:

In fact, member in structures will be aligned according to your
complier configuration.
Use #pragma pack(?) to specify packing alignment for structure
explicitly.
In your case, #pragma pack(1) should be used.

Yes, Thank your reply. But in my code it didn't use the #pragma
pack(?), not the #pragma align 1.
I don't know the difference between them. why the code use the
following:

#if ((CPU_FAMILY==I960) && (defined __GNUC__))
#pragma align 1
#endif

Could you give me the answer?
Thank you!

The code snippet means that if your processor is I960 family and you
are compiling the c code using GNU C style coding the the data will be
byte alignment.

In the code snippet mentioned by you, the alignment is playing a major
role hence you are seeing the correct results..probably your code is
4bytes aligned. Can you tell me what processor you are using ?

Probably you can check the alignment by printing the size of the three
structures and then comparing.

All the best,
Manish Gupta

Thank you for your reply. I am using the pentium processor. And the
result is
NODE_T has 8 bytes!
ARC_T has 8 bytes!
LEAF_T has 8 bytes!
Yes, if my compiler is 4bytes aligned. Maybe it is right!


.

Relevant Pages