cmd/compile: broken link https://rsc.googlecode.com/hg/testdata/slow.go in plive.go

[mdempsky]

In plive.go, there's this comment:

// the same type t. On https://rsc.googlecode.com/hg/testdata/slow.go, onebitwalktype1
// accounts for 40% of the 6g execution time.

The link no longer works though, and perhaps isn't even true anymore. We should update it appropriately.

/cc @rsc @griesemer

[mdempsky]

slow.go now resides at https://github.com/rsc/rsc/blob/master/testdata/slow.go

[mdempsky]

I just used cmd/compile -cpuprofile on slow.go, and the compiler's only spending 17% of its time in all of plive.go, most of which seems to be going towards livenessprologue and livenesssolve. It doesn't seem like onebitwalktype1 is a bottleneck for slow.go anymore, and it doesn't even show up.

Tangentially, compiling slow.go takes around 3 seconds on my laptop with Go 1.4's 6g, whereas at HEAD it takes around 1.8 seconds.

I think the comment can just be removed.

[gopherbot]

Change https://golang.org/cl/65110 mentions this issue: cmd/compile/internal/gc: update comment in plive.go