Wilco Dijkstra <Wilco.Dijkstra@xxxxxxx> writes: >> And do you think it worth us providing a parameter to alter the iteration so that the >> accuracy can be a trade-off of speed. > > What do you mean? We already have -mlow-precision-div (and -sqrt/-recip-sqrt). The suggestion was to have a parameter to control the number of steps, rather than always use the values that are currently hard-coded into aarch64.c. That sounds OK in principle. It would fix one of the downsides of the current code, in which users can force reciprocal approximation to be used at low precision, but can't force it to be used at the precisions normally chosen by -mtune. It's probably not worth promoting to a full -m option that in theory would be supported for evermore. But now that targets can define their own --params, it might make sense to use --params here. Thanks, Richard
