[LLVMdev] Instruction dependency in ARM backend

[pmon mail]

> You definitely can glue them together.
Do you mean instruction bundling?

I see that sometimes (I guess) some optimization does insert other
instructions between movw+movt pair. Is there a flag to say "don't touch
them"?


On Sun, Apr 6, 2014 at 8:42 PM, Anton Korobeynikov
<anton at korobeynikov.info>wrote:

> Hello
>
> > What should be the right approach to implement this?
> You definitely can glue them together. Alternatively, you can disable
> the generation of movt / movw instruction pairs at all. The latter
> probably looks the better solution give the target weirdness :)
>
> > Is this something I can describe in target description for ARM?
> If you mean .td files, then no. movt / movw pairs is inserted via
> "pseudo instruction expansion pass". Look into
> ARMExpandPseudoInsts.cpp
>
>
> --
> With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University
>
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