On 01/13/2012 10:58 AM, Richard Sandiford wrote:
> Yes, because new test ALWAYS includes the registers that were wrongly
> marked as dead by previous test due to REG_UNUSED and noclobber
> processing.
Or to put it another way: the insn-to-insn changes in the current liveness
sets are all produced by df_simulate_one_insn_{backwards,forwards}, which
uses the same information. So I don't think there's any reason why we
need to keep the current code as well.
Yes, both explanations are sound. I think the patch is good, too.
Paolo