Messages in this thread | | | Date | Thu, 12 Nov 2015 11:33:15 -0800 | From | "Shi, Yang" <> | Subject | Re: [PATCH 1/2] arm64: bpf: add 'store immediate' instruction |
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On 11/11/2015 4:39 AM, Will Deacon wrote: > On Wed, Nov 11, 2015 at 12:12:56PM +0000, Will Deacon wrote: >> On Tue, Nov 10, 2015 at 06:45:39PM -0800, Z Lim wrote: >>> On Tue, Nov 10, 2015 at 2:41 PM, Yang Shi <yang.shi@linaro.org> wrote: >>>> aarch64 doesn't have native store immediate instruction, such operation >>> >>> Actually, aarch64 does have "STR (immediate)". For arm64 JIT, we can >>> consider using it as an optimization. >> >> Yes, I'd definitely like to see that in preference to moving via a >> temporary register. > > Wait a second, we're both talking rubbish here :) The STR (immediate) > form is referring to the addressing mode, whereas this patch wants to > store an immediate value to memory, which does need moving to a register > first.
Yes, the immediate means immediate offset for addressing index. Doesn't mean to store immediate to memory.
I don't think any load-store architecture has store immediate instruction.
Thanks, Yang
> > So the original patch is fine. > > Will >
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