[Bug tree-optimization/128045] New: Match pattern for `convert semantics of round(x) function to floor(x+0.5)` can be simplified

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128045

            Bug ID: 128045
           Summary: Match pattern for `convert semantics of round(x)
                    function to floor(x+0.5)` can be simplified
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog, easyhack
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Currently it does:
```
 (simplify
  (cond (op:c (minus:s SSA_NAME@0 (floor SSA_NAME@0))
              (minus:s (ceil SSA_NAME@0) SSA_NAME@0))
        (bt SSA_NAME@0) (bf SSA_NAME@0))
```

But the `SSA_NAME@0` can just be @0 the whole way through.  This should remove
an extra check.