[Bug rtl-optimization/93565] Combine duplicates count trailing zero instructions

[wdijkstr at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93565

Wilco <wdijkstr at arm dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |wdijkstr at arm dot com

--- Comment #6 from Wilco <wdijkstr at arm dot com> ---
(In reply to Segher Boessenkool from comment #4)
> Why would that be unlikely?  It lengthens the lifetime of that pseudo,
> potentially significantly.

The move should be easy to remove since it is already known to be redundant. I
don't understand how you can say that the lifetime is increased when
duplicating the instruction is actually what increases the lifetime. Also it
requires extra registers to hold the two identical results.