PR16752[PATCH]: 'mode' attribute for unusual targets doesn't work properly.

[Stepan Dyatkovskiy]

Committed in r190926.
-Stepan.

Eli Friedman wrote:
> Sorry about the delayed response.
>
> XC mode is not valid on PPC; if there's a test trying to use it, the
> test is wrong.  Please just fix the test.
>
> -Eli
>
>
> On Tue, Sep 17, 2013 at 11:54 AM, Stepan Dyatkovskiy <stpworld at narod.ru
> <mailto:stpworld at narod.ru>> wrote:
>
>     Hi Eli,
>     I have to resend you PR16752 fix. Since I had changed it. The
>     previous one causes failures on some buildbots.
>     This fix also contains customization for PPC case:
>     For 'XC' mode (96 bit float) PPC uses 128 bit fp type.
>
>     -Stepan.
>
>     Eli Friedman wrote:
>
>         LGTM.
>
>         -Eli
>
>
>         On Mon, Sep 9, 2013 at 5:04 AM, Stepan Dyatkovskiy
>         <stpworld at narod.ru <mailto:stpworld at narod.ru>
>         <mailto:stpworld at narod.ru <mailto:stpworld at narod.ru>>> wrote:
>
>              Since I had split the patch and committed only ASTContext and
>              TargetInfo getIntTypeByWidth and friends, there is the
>         second patch,
>              that fixes PR16752 itself.
>
>              Please, find it in attachment for review.
>
>              -Stepan.
>              Eli Friedman wrote:
>
>                  On Tue, Sep 3, 2013 at 2:16 AM, Stepan Dyatkovskiy
>                  <stpworld at narod.ru <mailto:stpworld at narod.ru>
>         <mailto:stpworld at narod.ru <mailto:stpworld at narod.ru>>
>                  <mailto:stpworld at narod.ru <mailto:stpworld at narod.ru>
>         <mailto:stpworld at narod.ru <mailto:stpworld at narod.ru>>>> wrote:
>
>                       Hi Eli,
>                       Sorry for latency.
>                       As you remember this patch should correct 'mode' attr
>                       implementation. You proposed to use generic way of
>         type
>                  detection
>                       for each target: just scan for target types and
>         select one with
>                       suitable width.
>
>                       Unfortunately I can't commit patch with generic
>                  implementation. I
>                       got test failure for clang. And I expect more
>         failures for
>                  another
>                       targets. The reason is next.
>
>                       The target could still keep mode unsupported even
>         if it has
>                  type of
>                       suitable width. I mean the next.
>                       For example this string should cause error for i686
>                  machines (128
>                       bit float):
>                       typedef          float f128ibm __attribute__
>         ((mode (TF)));
>                       But in case of generic approach for all targets it
>         would be
>                  passed.
>                       In this case virtual functions allows to implement
>         exceptions.
>
>
>                  The generic implementation is still essentially
>         correct; the the
>                  issue
>                  is that getLongDoubleWidth() isn't actually the right
>         value to
>                  check.
>                     It returns "sizeof(long double) * 8", not the actual
>         width of the
>                  underlying float format.  You should be able to work
>         around this by
>                  checking getLongDoubleFormat() instead of
>         getLongDoubleWidth().
>
>                       In this case 'getIntTypeByWidth' may be a bit
>         confusing name.
>                       Instead it is supposed to return type for some
>         particular
>                  mode, not
>                       by width. Something like
>         getInt/RealTypeForMode(width, sign).
>                       Though, currently I kept the original name.
>
>
>                  If you want to change it, that's fine.
>
>                  -Eli
>
>
>
>
>