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Re: Incrementing volatiles?
- To: phdm at macqel dot be (Philippe De Muyter)
- Subject: Re: Incrementing volatiles?
- From: Joe Buck <jbuck at synopsys dot com>
- Date: Mon, 13 Jul 98 8:47:24 PDT
- Cc: egcs at cygnus dot com
> eieio stands for "Enforce In-Order Execution of I/O".
... and it is definitely my favorite name for an assembly language
instruction (the non-native-English speakers on the list presumably
don't know the childhood song "Old McDonald had a farm, E-I-E-I-O").
> Without it a powerpc
> processor assumes that it may reorder the load and stores to memory-mapped
> I/O registers.
It would seem that on processors with this property, yes, you should get
an eieio in cases where otherwise, the I/O order might change, at least
where it is really needed.
How do the Linux/ppc people deal with this? I see no "eieio" instructions
in the arch/ppc part of the 2.0.30 kernel.