https://issues.dlang.org/show_bug.cgi?id=22116

          Issue ID: 22116
           Summary: optimize values based on prior comparisons
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: bugzilla@digitalmars.com

Consider:

    bool b = (a == 3) ? a : 0;

which can be replaced with:

    bool b = (a == 3);

The idea is to do data flow analysis and note that `a` has the value of 3 or !=3 when on a leg of a conditional code path.

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