[Bug middle-end/125508] New: speed up cl_optimization_hash

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125508

            Bug ID: 125508
           Summary: speed up cl_optimization_hash
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---
            Target: aarch64

I was running the GCC testsuite on aarch64-linux-gnu (this is still with
checking turned on) and looking into the top functions and
iterative_hash_host_wide_int was the top function since cl_optimization_hash
calls it.


I think we should be using add_int here rather than add_hwint for most of
these.

That should speed up things slightly because the upper 32bits will be 0.
In fact most of these are going to be 0 or 1 even. So maybe there is a way to
optimize this even more.