Re: Add private syscalls to support NPTL

Andreas Schwab
2009-08-19T08:37:57Z

Brad Boyer <flar@allandria.com> writes:

> On Tue, Aug 18, 2009 at 11:07:26AM +0400, Maxim Kuvyrkov wrote:
>> The reason for this calling convention is to minimize difference in
>> invokation of the vDSO helper and the syscall. The helper gets its
>> arguments in a0 (mem), d0 (oldval) and d1 (newval); in a stub, which is
>> used when vDSO is not available, one then can do:
>>
>> movel %d0,%a1
>> movel #NR,%d0
>> trap #0
>
> Then wouldn't it make sense to use %d2 instead of %a1?

d2 is a callee-saved register, a1 isn't.

Andreas.

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Andreas Schwab, schwab@linux-m68k.org
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