[Bug c/60619] New: new -solve-sign-conflicts at -Wsign-compare cases (easy work)

[aleks at physik dot tu-berlin.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60619

            Bug ID: 60619
           Summary: new -solve-sign-conflicts at -Wsign-compare cases
                    (easy work)
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: aleks at physik dot tu-berlin.de

GCC detects sign problems (-Wconversion -Wsign-compare -Wsign-conversion).

int i; unsigned u; if (u == i) // warning sign ..

my gcc feature suggestion: new -solve-sign-conflicts
==> some problems could be solved by gcc alone (if switch).

I could provide compare functions, that are used by gcc in case of above
warning and the new switch.

// e.g. 3 compare functions, handle signs
inline int cmp_su32_equal(int s, uint32 u) { /* == */
    const int o = s | (int) u;
    if (s != (int) u) return 0;
    if (o < 0) return 0; // (s<0) || (u>INT_MAX)
    return 1;
}
inline int cmp_su32_lt(int s, uint32 u) { /* < */
    const int o = s | (int) u;
    if (o < 0) return 1; // (s<0) || (u>INT_MAX)
    if (s < (int) u) return 1;
    return 0; // return (s < (int) u);
}
inline int cmp_su32_gt(int s, uint32 u) { /* > */
    const int o = s | (int) u;
    if (o < 0) return 0; // (s<0) || (u>INT_MAX)
    if (s > (int) u) return 1;
    return 0; // return (s > (int) u);
}