[PATCH libXi] 1UL may be 4 bytes, force to 1ULL

Jeremy Huddleston jeremyhu at apple.com
Tue Sep 20 10:01:45 PDT 2011

```I just realized I made (at least one) error in the inline functions I wrote below.  s/< 0/< 1/ ... there're probably others, but that just emphasizes my point that there should be conversion routines rather than repeating this code with possible error in other locations.

On Sep 19, 2011, at 7:03 PM, Jeremy Huddleston wrote:

> I'm curious... why is the cls_wire->increment.frac getting cast to unsigned int?  It's already typed as uint32_t.
>
> Looking at the context a bit more, I agree with Jamey that this should work (with or without explicit casts):
>
> cls_lib->increment  = (double)cls_wire->increment.integral;
> cls_lib->increment += ldexp((double)cls_wire->increment.frac, -32);
>
> But I think it would be more useful to provide something like this in the proto to help with conversion:
>
> static inline double fp1616_to_double(FP1616 in) {
>    double ret;
>    ret = (double)(in >> 16);
>    ret += ldexp((double)(in & 0xff), -16);
>    return ret;
> }
>
> static inline double fp3232_to_double(FP3232 in) {
>    double ret;
>    ret = (double)in.integral;
>    ret += ldexp((double)in.frac, -32);
>    return ret;
> }
>
>
> static FP1616 double double_to_fp1616(double in) {
>    FP1616 ret;
>    int32_t integral
>    double frac_f;
>    uint32_t frac_d;
>
>    integral = (int32_t)in << 16;
>    frac_f = in - (double)((int32_t)(in));
>
>    if (fabs(frac_f) < 0) {
>      frac_d = (uint32_t)ldexp(frac_f,16);
>    } else {
>      /* crap */
>      frac_d = 0;
>    }
>
>    ret = integral << 16;
>    ret |= frac & 0xff;
>    return ret;
> }
>
> static FP3232 double double_to_fp3232(double in) {
>    FP3232 ret;
>    int32_t integral
>    double frac_f;
>    uint32_t frac_d;
>
>    integral = (int32_t)in << 16;
>    frac_f = in - (double)((int32_t)(in));
>
>    if (fabs(frac_f) < 0) {
>      frac_d = (uint32_t)ldexp(frac_f,16);
>    } else {
>      /* crap */
>      frac_d = 0;
>    }
>
>    ret.integral = integral;
>    ret.frac = frac_d;
>    return ret;
> }
>
> On Sep 19, 2011, at 5:37 PM, Jamey Sharp wrote:
>
>> I'm a bit skeptical... Would ldexp(frac, -32) work for you? Otherwise
>> I'd argue for (UINT64_C(1) << 32).
>>
>> Jamey
>>
>> On Tue, Sep 20, 2011 at 10:19:54AM +1000, Peter Hutterer wrote:
>>> Reported-by: Jeremy Huddleston <jeremyhu at apple.com>
>>> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
>>> ---
>>> something like this good enough?
>>>
>>> src/XExtInt.c |    2 +-
>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/src/XExtInt.c b/src/XExtInt.c
>>> index d74a8d4..4009285 100644
>>> --- a/src/XExtInt.c
>>> +++ b/src/XExtInt.c
>>> @@ -1577,7 +1577,7 @@ copy_classes(XIDeviceInfo* to, xXIAnyInfo* from, int *nclasses)
>>>                    cls_lib->scroll_type= cls_wire->scroll_type;
>>>                    cls_lib->flags      = cls_wire->flags;
>>>                    cls_lib->increment  = cls_wire->increment.integral;
>>> -                    cls_lib->increment += (unsigned int)cls_wire->increment.frac/(double)(1UL << 32);
>>> +                    cls_lib->increment += (unsigned int)cls_wire->increment.frac/(double)(1ULL << 32);
>>>
>>>                    to->classes[cls_idx++] = any_lib;
>>>                }
>>> --
>>> 1.7.6
>>>
>>> _______________________________________________
>>> xorg-devel at lists.x.org: X.Org development
>>> Archives: http://lists.x.org/archives/xorg-devel
>>> Info: http://lists.x.org/mailman/listinfo/xorg-devel
>

---
Jeremy Huddleston

Rebuild Sudan
- Board of Directors
- http://www.rebuildsudan.org

Berkeley Foundation for Opportunities in Information Technology
- http://www.bfoit.org

```