(you can then replace .double with .quad to load your own bit pattern
instead of having to work our the desired float, see:
https://github.com/cirosantilli/linux-kernel-module-cheat/blob/657c59249e56d861bb0a437a1b1c757797281910/userland/arch/aarch64/gas_data_sizes.S#L26
)

On Mon, Jan 13, 2020 at 10:41 AM Ciro Santilli <[email protected]> wrote:
>
> There is no silly question.
>
> I think the easiest thing is to put the desired bit patterns in memory
> use LD1 as shown here:
> https://github.com/cirosantilli/linux-kernel-module-cheat/blob/657c59249e56d861bb0a437a1b1c757797281910/userland/arch/aarch64/fadd_vector.S#L21
>
> This may also be of interest:
> https://github.com/cirosantilli/linux-kernel-module-cheat/blob/657c59249e56d861bb0a437a1b1c757797281910/userland/arch/aarch64/gdb_tests/floating_registers.S
>
> On Mon, Jan 13, 2020 at 3:29 AM Gabe Black <[email protected]> wrote:
> >
> > Hi folks. I do most of my aarch64 assembly level programming by example, ie
> > by just doing what other code I can find is already doing. I'm trying to
> > test some code I wrote to checkpoint the FP state in a fast model ARM CPU,
> > and to do that I need to load known values into those registers to make
> > sure they end up in the right place in the checkpoint.
> >
> > What assembly instruction should I use to maximally load up those registers
> > with a known bit pattern? Ideally it would be something where I could tell
> > that the right bits ended up in the right register and in the right part of
> > the register.
> >
> > This particular CPU (CortexA76) does not seem to have SVE, so this would
> > need to be a neon type instruction. Sorry for the dumb question, but I
> > figure this might be a very easy question for somebody to answer which
> > would save me a lot of trial and error trying to find the right instruction
> > and syntax to get it going.
> >
> > Thanks!
> > Gabe
> > _______________________________________________
> > gem5-dev mailing list
> > [email protected]
> > http://m5sim.org/mailman/listinfo/gem5-dev
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