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Equivalent of __packed for arm-linux-gcc ?



Hi all,
            Quoted from "http://www.arm.com/support/faqdev/1228.html";.

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"For example if a pointer pointing at the address 0x8006 was loaded from, then you might expect to load the contents of bytes from 0x8006, 0x8007, 0x8008 and 0x8009. However on the ARM, such an access would actually load the rotated contents of bytes from 0x8004, 0x8005, 0x8006 and 0x8007.

Thus if you wish to define a pointer to a word that can be at any address (i.e. that can be at a non-natural alignment) then you must specify this using the __packed qualifier when defining the pointer:
  __packed int *pi; // pointer to unaligned int

The ARM compilers will not then use an LDR, but instead generate code which correctly accesses the value regardless of the alignment of the pointer. This code generated will be a sequence of byte accesses, or variable alignment-dependent shifting and masking (depending on the compile options) and will therefore incur a performance and code size penalty. "

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iam stuck with this problem, since many days. I have read about this problem from several arm-mailing lists.Now the scene is , ive understood the problem but failed to get a solution, from arm-linux-gcc for this .

the following definition would work armcc :
How can i declare  something of this kind using arm-linux-gcc?

  __packed int *pi; // pointer to unaligned int

thanks for your time.

cheers,
Amith

PS: using __attribute__((packed)) is not used for this case. i got confused initially. Now i realise it is for something else.













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