Thanks for linking this here. One thing that I did not follow up at the issue; why do we see the FMA being applied when the value is a slice element, but not when it's a single float64 value?
Second query, are there plans for adding FMA support to amd64 akin to how it is on arm64? Dan On Mon, 2020-01-13 at 15:45 -0800, 'Keith Randall' via golang-nuts wrote: > Note: discussion at https://github.com/golang/go/issues/36536 . TL;DR > fused > floating point multiply-add gives higher precision results. > > On Sunday, January 12, 2020 at 8:19:54 PM UTC-8, kortschak wrote: > > > > I am going through failures that I see in Gonum tests when we build > > on > > arm64 (Travis now provide this). > > > > In many cases there are slight differences that I'm OK with adding > > a > > tolerance to accept, but in one case (stat.ROC[0][1]) I see an > > error > > that can be completely avoided by changing the expression from what > > is > > at [1] to > > > > ``` > > for i := range tpr { > > tpr[i] = 1 - tpr[i]/nPos > > fpr[i] = 1 - fpr[i]/nNeg > > } > > ``` > > > > Should I expect `inv := 1/c; v *= inv` and `v /= c` to give the > > same > > results for reasonable cases? (or at least to match the behaviour > > on > > amd64/386/arm - which all agree). > > > > thanks > > Dan > > > > [0]https://godoc.org/gonum.org/v1/gonum/stat#ROC > > [1] > > > > https://github.com/gonum/gonum/blob/683ee363d56e77121c6640345bb9d40644f02a1f/stat/roc.go#L107-L114 > > > > > > > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/d4c647c4e76f979b8e71cd14278978b795d14045.camel%40kortschak.io.
