🚀 go-pugleaf

In the field of Logic Programming, we have a kind of optimization
technique called the Last Call Optimization.  The idea is simple.

	p(a,b,c)
	{	x(a);
		y(b);
		z(c);
	}

In the above procedure, we may discard the current stack frame (or reg
window in Sparc) before calling z.  We then replace the call z
instruction by a jump instruction.

	p(a)
	{	x(a);
	}

In the above kind of procedure where there is only one call, no stack
frame is necessary.  It can be optimized as if it were a leaf procedure.

It is a sad thing to notice that such a nice optimization is not
implemented in languages other than Prolog and on RISC architectures.

				Tong Bo-Ming
				Department of Computer Science
				The Chinese University of Hong Kong