Hi! On Wed, Jan 22, 2020 at 12:06:02PM +0100, Henri Cloetens wrote: > Simplified, it looks as follows: > > (define_insn "movdi" > [(set (match_operand:DI 0 "blueproc_nonimmediate_operand" "=r,r,m") > (match_operand:DI 1 "input_operand" "r,m,r"))] > > - The options 2 (m to r) and 3 (r to m), that is clear. > - The option 1 (r to r), the processor has no instruction for it. It What you call "options 1, 2, and 3" are called "alternatives 0, 1, and 2". > needs to be translated to > 2x the movsi instruction. Now, I would prefer to avoid duplicating > the code written under the > 'movsi', and call the movsi definition. > Q. Is this possible ?. Of course ;-) > I mean, I found it can be done with define_split, but then the > compiler gets confused, splits the > instruction, and cannot do the rename any more to avoid the > copying. > (There are cases where it should rename, and cases where it should > copy.) So, it should be done > in the define_insn, but I find no way to do it. This is one of the cases where you want to split only when reload_completed. So your split condition might be "reload_completed && which_alternative == 0" for example. HTH, Segher
