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Re: ARM peephole2 from 2003 never merged, still valid


On Thu, Jun 06, 2019 at 05:06:35PM +0100, Richard Earnshaw (lists) wrote:
> The reason combine doesn't catch this is because at the time it runs the
> MOV is in a different basic block.  Later on it is sunk into the same
> basic block, but it's then too late to do the merge.

Or you could say the MOV didn't even exist yet: the insn that is merged
by the peephole is created by the prologue code, eventually.

This isn't really a target problem, it is very much generic, but I don't
see a better solution than a peephole either.


Segher


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