Messages in this thread | | | Date | Wed, 10 Mar 1999 12:42:08 -0800 (PST) | From | Jeremy Fitzhardinge <> | Subject | Re: Linux/IA-64 byte order |
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On 10-Mar-99 Zygo Blaxell wrote: > The one caveat is that you can't do a memcpy() from BE to LE and > vice-versa. If you do, then you have BE data on an LE page and the magic > translation doesn't work properly any more.
It's worse than that. A simple byte-at-a-time memcpy will work OK in some predictable way, but optimised memcpy implementation will use a mixture of byte, word and even cache line memory reads/writes depending on the CPU and memory architecture. This will completely confuse the hardware byte-swizzler and you end up with a complete mess.
The solution, I suppose, is to have memory instructions with always use a fixed endianness, regardless of what the page endianness properties are, but "clean" and "elegant" are long gone.
J
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