On Thu, Dec 10, 2015 at 01:26:06PM +0100, Eric Botcazou wrote: > Thanks. It seems a little odd for the condition to test the POS (operand #2) > and not also the LEN (operand #1) of the ZERO_EXTRACT before returning true, > but I'm not sure what the test would be given the above example. Or maybe > it's implicitly contained in the POS test because of the little-endian case.
The test looks weird because it only handles the LE case. What it says is simply "if copying the rightmost part of a register to itself", and it then does not matter how many bits are copied. This really does not belong here I'd say (whatever creates this RTL should already simplify it), but I'm just fixing a bug ;-) Segher
