Hi, while lacking the deep insight into GCC internals most of you have, I'd never the less like to ask you to be very prudent concerning the issue of removal of seemingly unnecessary RTL optimizations. In contrast to 32 bit targets, for 8 and 16 bit targets the RTL representation possibly might look completely different than the corresponding tree representation of the code: In my opinion, now that the new tree optimizations exist, it might finally be a good approach to let all the optimizations that could be done on original DI/SI/HI mode expressions be done on the tree level already. Then one could expand the DI/SI/HI mode expressions at RTL generation to only refer to the processor's native word length modes. What one would get then is a RTL which has about nothing to do with the corresponding tree representation.
For 8/16 bit target and gcc3 it seems that it used to be necessary to do the expansion/splitting extremely late since optimizations on SI/HI mode expressions required to keep SI/HI mode objects at least until reload. Now hopefully one could consider to do the splitting much earlier and with the help of the existing RTL optimizers one might be able to find many additional optimization possibilities. I think that it would be a pity if one could no longer find these optimizations because the corresponding RTL optimizers have been removed. Yours, Björn
