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Re: [PATCH/RFA] SH: work around insn duplication issues


Joern Rennecke <joern.rennecke@superh.com> wrote:
>>         * config/sh/sh.c (unspec_caller_rtx_p): New.
>>         (sh_cannot_copy_insn_p): New.
>>         (TARGET_CANNOT_COPY_INSN_P): New.
> 
> OK for now.

Thanks. I'll check it in ASAP.

> In order to allow basic block reordering in some of the
> affected cases, we have to consider that the load can
> be copied without the call, but the call cannot be copied
> without the load.  Of course, if the load was duplicated first,
> the call would have to be copied together with all the loads,
> or not at all.  So we'd want to change the insn patterns to
> reference each other (e.g. we could have an insn_list inside
> the unspecs), and have a target hook that is kind of a copy
> constructor that can fail.  The function used for the default
> setting of that hook - plain copying with label mapping -
> should be global so that it can be used to handle the ordinary
> cases in the various target specific definitions for this hook.

I didn't consider it. Thank you for the explanation.

Regards,
	kaz


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