https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118384

--- Comment #12 from Jeffrey A. Law <law at gcc dot gnu.org> ---
I played with Raphael's expander adjustment in this space during stage3 last
year, but couldn't get it to behave exactly the way I wanted.  Essentially I
could get the simple testcases to produce better code, but when I looked at
larger codebases it was regresssing and I didn't feel it was the time to open
that can of worms.

Note that if the datatype is the same size as the target word, a neg
instruction would likely be better than the shift pair.  No idea what's going
to be better when the datatype is 2X the target word -- I haven't looked at
that space at all ;)

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