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

Jeremy Huddleston jeremyhu at apple.com
Mon Sep 19 19:03:51 PDT 2011

```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

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