On Thu, 8 Aug 2019, Segher Boessenkool wrote: > These current patterns all take the same mode for all inputs and outputs > (that's what <mode>3 indicates, say, fadddf3). You will need to define > something that takes two SFs in and produces a DF. That cannot really
For example, md.texi describes standard patterns such as mulhisi3 that multiply two HImode values and produce an SImode result (widening integer multiply). Using a similar naming pattern, you might have a pattern adddfsf3 that multiplies two DFmode values and produces an SFmode result (or you could call it something like add_truncdfsf3 if you wish to emphasise the truncation involved, for example). Similarly addtfsf3 that multiplies TFmode and produces an SFmode result, and so on. Of course these names need documenting (and you need corresponding RTL for them to generate that distinguishes the fused add+truncate from the different RTL for separate addition and truncation with double rounding). In cases where long double and double have the same mode, the daddl function should use the existing adddf3 pattern. -- Joseph S. Myers jos...@codesourcery.com
