Re: Bug#609371: linux-image-2.6.37-trunk-sparc64: module scsi_mod:Unknown relocation: 36

[David Miller]

From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Date: Wed, 19 Jan 2011 17:13:27 -0500

> Hrm, I'd like to see what kind of ill-conceived 32-bit architecture would
> generate a unaligned access for a 32-bit aligned u64. Do you have examples in
> mind ? By definition, the memory accesses should be at most 32-bit, no ? AFAIK,
> gcc treats u64 as two distinct reads on all 32-bit architectures.

Sparc 32-bit has 64-bit loads and stores, GCC uses them because the ABI
specifies that every structure is at least 8 byte aligned.

> gcc on my sparc64 box (32-bit userland) disagrees with you here ;) Using
> gcc (Debian 4.3.3-14) 4.3.3, here is a demonstration that, indeed, "packed"
> generates aweful code, but that "packed, aligned(4 or 8)" generates pretty
> decent code:

Amazing, if this works then do it.

But please document this fully with comments and such :-)
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