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Re: powerpc & unaligned block moves with fp registers
- To: dje at watson dot ibm dot com
- Subject: Re: powerpc & unaligned block moves with fp registers
- From: degger at fhm dot edu
- Date: Mon, 12 Nov 2001 16:49:53 +0100 (CET)
- Cc: gcc at gcc dot gnu dot org
- Reply-to: degger at fhm dot edu
On 11 Nov, David Edelsohn wrote:
>> Depends on the CPU, The latest PPCs for example combine
>> accesses under most conditions, however having several
>> accesses instead of a single one will lead to higher I-Cache
>> pressure. I would prefer aligning the complete structure on a
>> natural boundary and extract single components by masking
> Aligning the structure on particular boundaries violates the
> existing PowerPC ABIs. Next...
So the linker is not free to choose where to put the structures in
memory? Dang, I haven't thought about this I have to admit. At least we
could issue a warning telling the developper to reconsider the structure
entries to get a better alignment.