[LLVMdev] [cfe-dev] Disable Short-Circuit Evaluation?

[Konstantin Tokarev]

10.10.2011, 18:29, "David A. Greene" <greened at obbligato.org>:
> Justin Holewinski <justin.holewinski at gmail.com> writes:
>
>>  int globalIndexY2 = get_group_id(1)*186 + 6*get_local_id(1) + 2 + 1;
>>  bool valid2       = validX && globalIndexY2 >= 4 && globalIndexY2 < 3910;
>>
>>  Clang, even at -O0, is performing short-circuit evaluation of these
>>  expressions, resulting in a fair number of branch instructions being
>>  generated.
>
> It has to.  This is the semantics of C.  Short-circuiting is used to
> defend against all sorts of undefined behavior in real code.

More precisely, && and || are sequence points (though in C++ they may not be
sequence points if respective operator is overloaded)

[1] http://en.wikipedia.org/wiki/Sequence_point

-- 
Regards,
Konstantin