• via Digitalmars-d-bugs (26/26) Jul 11 2017 https://issues.dlang.org/show_bug.cgi?id=17637

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=17637

          Issue ID: 17637
           Summary: Integral promotion rules not being followed
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: bugzilla digitalmars.com

Johan Engelen reports:


  import core.stdc.stdio;

  void main() {
    uint total = 0;
    void add(int x) { total += x; }
    ubyte popCount() { return 5; }

    add(popCount());
    add(-popCount());
    printf("%u\n", total);    // different result from C
  }

The trouble is that -popCount() negates the ubyte before promoting to int,
instead of after.

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