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Re: how to keep a hard register across multiple instrutions?


On 3 November 2014 21:51, David Kang <dkang@isi.edu> wrote:
>
>  Thank you for the tips.
> I tried the following condition for split.
>
>   "reload_completed && FP_REG_P (operands[0])"
>
> But, the registers are still changed.
> How can I specify "after register allocation" in the split condition?

Are you sure that your problem is that the split is too early, or
could you suffering
from later register renumbering?
You can get a set of dump files for all rtl passes by adding the -da
option to gcc / cc1,
so that you can see exactly when things go wrong.
I would suspect the register renaming pass causing you trouble.
You might have to define HARD_REGNO_RENAME_OK suitably for your target.


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