Unaligned access question

Peter Chubb
2003-09-25T02:04:55Z

>>>>> "Ian" = Ian Wienand <ianw@gelato.unsw.edu.au> writes:

Ian> Hi,

Ian> This isn't directly related to kernel development, but I am a bit
Ian> stumped as to why my test program below causes an unaligned
Ian> access when 'i' is 7 (that is, when it tries to access across a
Ian> 64 bit boundary of 'array'). It's counter intuitive to me, I
Ian> would have expected it either fault on all loads (for every value
Ian> of 'i') or to have not faulted at all.

The IA64 can handle unaligned acceses itself if they're within a small
window -- eight bytes for Itanium-2, can't remember for Itanium-I --
and if PSR.ac is 0.

--
Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au
You are lost in a maze of BitKeeper repositories, all slightly different.