On Thu, Dec 11, 2014 at 03:13:50PM +0800, Bin.Cheng wrote: > So I am wondering if I can rely on INSN_LUID checking orders of > difference instruction. If it can be done, I can easily differentiate > live range shrink and extend. > Further question is, if we don't insert new insns, can I use INSN_LUID > safely for this purpose?
I0 is before I1 is before I2 is before I3; one of the first things try_combine does is make sure this is true (by swapping the names around if necessary). The LUIDs are in strictly increasing order, and they stay that way: combine never moves or inserts insns. Segher
