[llvm-commits] [llvm] r80907 - /llvm/trunk/lib/Analysis/ProfileInfoLoaderPass.cpp

[Andreas Neustifter]

Hi,

Daniel Dunbar wrote:
> On Thu, Sep 3, 2009 at 12:53 AM, Andreas Neustifter<astifter-llvm at gmx.at> wrote:
>> Hi,
>>
>> thank you very much for investigating this!
>>
>> Daniel Dunbar wrote:
>>> -  if (weight != (unsigned)MissingValue) {
>>> +  if (weight != ~0U) {
>> Since allmost all my other development takes place on platforms that do
>> not even support floating point my float-typecasting knowledge is a bit
>> rusty.
>>
>> If you have time: can you explain why this is necessary and why the cast
>> from double to unsigned does not work? (At least not on all platforms...)
> 
> I didn't know this off the top of my head either, but the relevant
> language for C99 (I presume C++ is similar is):
> --
> 6.3.1.4p1: When a finite value of real floating type is converted to
> an integer type other than _Bool, the fractional part is discarded
> (i.e., the value is truncated toward zero). If the value of the
> integral part cannot be represented by the integer type, the behavior
> is undefined.
> --

Thanks, so maybe we should convert all the counters to (signed) int64_t
to clean up this problem and get larger counters...

Andi

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