vrp?

[Richard Henderson]

Any idea what the state of the last value-range propagation patch is?

I've been looking at killing the cse-follow-jumps nonsense from cse.c,
and one case we're missing by removing it is

	if (x == 0)
	  foo ();
	else if (x == 0)
	  bar ();

The current cse code marks (x != 0) true on the else branch of the
first if.  But our current gcse code has no way to make (x = NOT(0))
available on an edge.

I wouldn't think we'd need too terribly strong VRP to replace what
cse.c does now, but given how often this shows up within gcc source
itself I don't think I can kill what we have without a replacement.

Thoughts?


r~