2009/2/17 Ian Lance Taylor <i...@google.com>: > > The problem with reload is that it interferes with register allocation. > Even if gcc had a perfect register allocator, we would still generate > suboptimal code because reload would mess up the allocation. The key to > solving that problem is that we need to do instruction selection (in gcc > terms, picking which insn alternative to use) either before register > allocation or in conjunction with it.
I have a strong opinion that better to have a right insn's before the register allocation. (right insn is an insn which satisfies it's constraints.) Because of that idea I have realised pre-relod in new-ra. (I'm agree that pre-reload is an ugly pieces of code) Even more, today I have a set of experiments with pre-reload pass before IRA. I have founded that IRA costs calculation process work better if I have a right insn's before IRA. Denis.
