On Fri, Jun 2, 2023 at 8:45 AM Mason <slash.tmp@xxxxxxx> wrote: > > On 01/06/2023 10:40, Uros Bizjak wrote: > [...] > > There is no use case to maintain two > > interleaved carry chains, > > What do you mean by "there is no use-case" ? > Are you saying ADCX/ADOX are useless? The advertised use case for dual addc instructions is big integer operations. I read that somewhere in the Intel docs several years ago. When I benchmarked ADCX/ADOX several years ago, ADCX/ADOX were slower than using a single ADDC. So I stayed with ADDC. Maybe cpu manufacturers have improved things nowadays. Jeff
