[PATCH] Keep lattice abstract in the SSA propagator, substitue lattice values at defs

[Paolo Bonzini]

On 08/08/2010 04:44 AM, Richard Guenther wrote:
> arithmetic.  But - we can do so if reassociating constants only
> as in the example above.  Because if (L43b_216 - 1) - 2147483648
> doesn't overflow then L43b_216 + 2147483647 doesn't either.

Huh?

a - 1 - 2147483648 is valid if a >= 1.

a + 2147483647 is valid if a < 1.

Paolo