[cfe-commits] r76911 - /cfe/trunk/lib/Analysis/CFG.cpp

[Sebastian Redl]

Ted Kremenek wrote:
> On Jul 23, 2009, at 9:33 PM, Eli Friedman wrote:
>   
>> (int)x == false is semantically equivalent to (int)x == 0 due to
>> integer promotion rules.  That said, it is slightly confusing the way
>> it's written.
>>     
>
>
> The problem isn't with 'x == 0', but with 'x == -1'.  Since (I  
> believe) both '1' and '-1' convert to true when int is casted to a  
> bool, the 'KnownVal == true' would evaluate to true in both cases  
> (which isn't the desired behavior).
>   
Integer promotion rules are the same no matter the values. In KnownVal
== true the 'true' literal is converted to the integer 1, and KnownVal
is not touched.

Sebastian