which is faster

[dis1411]

bool func(int* i)
{
return (*i == 5);
}

bool func(const int& i)
{
return (i == 5);
}

[SpS]

Profile and check.

[DNA7433]

I would bet the latter.

[penagate]

A good compiler should optimise both to the same.

[dis1411]

i would agree with penagate... however i am providing a simplified situation.. so ignore compiler omptimizations

[sunburnt]

i would agree with penagate... however i am providing a simplified situation.. so ignore compiler omptimizations

References, behind the scene, are pointers, just with the dereferencing done for you -- there's no way around it. I would wager that regardless of optimization, the machine code is the same.

[CornedBee]

Non-optimizing compilers will generate the same code. But by non-optimizing, I mean the very worst load-for-every-read style compilers.
For good compilers that however have no information about the content of these two functions, calling the second one could be faster, because the argument is a reference to const. If the compiler keeps the passed value in a callee-saved register in the calling function, it doesn't have to generate code to read it back in from memory, because it can't have changed.
If the compiler has access to the body of the functions, it should again generate the same code, because it's trivial to prove that the value isn't actually modified. It should also inline the functions if that is enabled.