On 05/21/2015 05:39 AM, Segher Boessenkool wrote: >> > Trying 18, 9 -> 24: >> > Failed to match this instruction: >> > (set (reg:DI 4 4 [+8 ]) >> > (plus:DI (plus:DI (reg:DI 5 5 [ val+8 ]) >> > (reg:DI 76 ca)) >> > (reg:DI 169 [+8 ]))) > For some reason it has the CA reg not last. I think we should add to > the canonicalisation rules so that fixed regs sort after other regs. > That requires a lot of testing.
Actually, I believe that the way CA is modeled at the moment is dangerous. It's not a 64-bit value, but a 1-bit value. If we rearrange the expanded rtl to be (zero_extend:DI (reg:BI CA)), then normal canonicalization rules will apply and it'll always appear first in the chain of PLUS. r~
