linux/include/asm-x86_64/unaligned.h

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#ifndef __X8664_UNALIGNED_H
#define __X8664_UNALIGNED_H
/*
* The x86-64 can do unaligned accesses itself.
*
* The strange macros are there to make sure these can't
* be misused in a way that makes them not work on other
* architectures where unaligned accesses aren't as simple.
*/
/**
* get_unaligned - get value from possibly mis-aligned location
* @ptr: pointer to value
*
* This macro should be used for accessing values larger in size than
* single bytes at locations that are expected to be improperly aligned,
* e.g. retrieving a u16 value from a location not u16-aligned.
*
* Note that unaligned accesses can be very expensive on some architectures.
*/
#define get_unaligned(ptr) (*(ptr))
/**
* put_unaligned - put value to a possibly mis-aligned location
* @val: value to place
* @ptr: pointer to location
*
* This macro should be used for placing values larger in size than
* single bytes at locations that are expected to be improperly aligned,
* e.g. writing a u16 value to a location not u16-aligned.
*
* Note that unaligned accesses can be very expensive on some architectures.
*/
#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
#endif