[OT] compiler optimisations

[via Digitalmars-d]

Interestingly only clang understands that an upcast will prevent 
the overflow:

int foo(unsigned int a)
{
	if (a > 5)
		return ((unsigned long long)a * 3) / 3;
	else
		return 0;
}

Is compiled to compact code in clang:

	xorl	%eax, %eax
	cmpl	$5, %edi
	cmoval	%edi, %eax
	retq