[Bug rtl-optimization/82889] Unnecessary sign extension of int32 to int64

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82889

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |law at redhat dot com

--- Comment #3 from Jeffrey A. Law <law at redhat dot com> ---
That would seem possible.  We'd turn expansion into a dominator walk with
embedded range analysis.  We'd then be able to perform queries as we expand
from trees/ssa into RTL.

I haven't looked at the tree/ssa->rtl expansion bits since Matz's (?)
reorganization a few years ago.  I don't know how difficult it would be to turn
it into a dominator walk over the blocks.

Alternately we'd have to wait for Andrew's work to be able to perform the
queries purely on-demand.