> Date: Tue, 20 Dec 2005 11:13:06 +0100 (CET) > From: Steven Bosscher <[EMAIL PROTECTED]>
> You really have to wonder if cleaning up this jump is a job combine > should be doing. I want it done there *only* because that's what it does for the similar but even more complex cc0 code and because combine does multi-insn simplifications in general. I suggest not being hung up on it being a jump that's simplified. Anyhow, I'd like to disconnect the un-cc0-ification of the CRIS port while retaining performance, from overhaul of GCC passes as much as possible, please, however TRT the overhaul may be. > I would have thought we'd clean this up _before_ > combine Me too... Might be a simple oversight somewhere. I'll have a closer look; seems at a glance that gcse thinks it does this. > (and no, I don't mean the tree optimizers, but e.g. CSE, or jump > bypassing (even though the latter doesn't work for critical > edges)). FWIW, jump bypassing doesn't do anything transformationwise but calling the usual cfgcleanup things. CFG apparently doesn't perform the necessary kind of simplifications. See rest_of_handle_jump2. > Are > there other cases, you think, where we fail to combine 2 insns into 2 > cheaper ones?? I don't know, but as combine seems to be the only pass performing inter-insn simplifications, I'd guess so. brgds, H-P
