Optimisation possibilities: current, future and enhancements

[kinke via Digitalmars-d]

I found it hard to believe LDC generates such crappy code when 
optimizing. These are my results using LDC master on Win64 (`ldc2 
-O -release -output-s`):

struct Foo
{
     immutable _u = 8;
     int foo() const
     {
         return 8 * _u;
     }
}
int use(ref const(Foo) foo)
{
     return foo.foo() + foo.foo();
}

int main()
{
     Foo f;
     return use(f);
}


_D7current3Foo3fooMxFZi:
	movl	(%rcx), %eax
	shll	$3, %eax
	retq

_D7current3useFKxS7current3FooZi:
	movl	(%rcx), %eax
	shll	$4, %eax
	retq

_Dmain:
	movl	$128, %eax
	retq

Sure, Foo.foo() and use() could return a constant, but otherwise 
it can't get much better than this.