On Tue, Nov 11, 2014 at 12:21:49PM +0530, Aravinda Prasad wrote: > > > On Tuesday 11 November 2014 11:41 AM, David Gibson wrote: > > On Tue, Nov 11, 2014 at 11:18:05AM +0530, Aravinda Prasad wrote: > >> > >> > >> On Tuesday 11 November 2014 08:49 AM, David Gibson wrote: > >>> On Thu, Nov 06, 2014 at 03:30:01PM +0530, Aravinda Prasad wrote: > >>>> On Wednesday 05 November 2014 09:16 PM, Tom Musta wrote: > >>>>> On 11/5/2014 2:32 AM, Alexander Graf wrote: > >>>>>> On 05.11.14 08:13, Aravinda Prasad wrote: > >>> > >>> [snip] > >>>>>>> + /* > >>>>>>> + * ori r3,r3,KVMPPC_H_REPORT_MC_ERR. The KVMPPC_H_REPORT_MC_ERR > >>>>>>> + * value is patched below > >>>>>>> + */ > >>>>>>> +1: ori 3,3,0 > >>>>> > >>>>> Why do "li 3,0" followed by "ori 3,3,X"? Isn't this just "li 3,X" ? > >>>>> (aka "addi 3,0,X") > >>>> > >>>> I remember I first tried doing li r3,X but faced some problem (but not > >>>> able to exactly recall what was the problem) may be due to not familiar > >>>> with ppc assembly. > >>> > >>> This would be because with the offset to the private hcalls, the > >>> actual hcall number is 0xf003, which means an li instruction will sign > >>> extend it incorrectly. So you will need two instructions to load the > >>> number. > >> > >> hmm.. ok > > > > At least, I think you'll need to instructions. I don't remember for > > certain if 'ori 3,0,X' will OR X with literal 0 or the contents of r0. > > It is ORed with r0 > > >From ISA: > > ori RA,RS,UI > > (RA) <- (RS) | (0 || UI) > > The contents of register RS are ORed with 0 || UI and > the result is placed into register RA.
Right, thought so. So unless there's some instruction I haven't
thought of, you'll need two instructions to load the value.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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