Re: GHC build time graphs

On Tue, Feb 9, 2016 at 11:20 AM, Karel Gardas wrote:

On 01/28/16 11:34 PM, Ben Gamari wrote:

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Joachim Breitner writes:

Hi Oleg,

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Am Freitag, den 29.01.2016, 00:22 +0200 schrieb Oleg Grenrus:

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Is the same compiler used to build HEAD and 7.10,1?

Good call. In fact, no: 7.10.1 is built with 7.6.3, while HEAD is built with 7.10.3.

Anthony’s link, i.e.

https://perf.haskell.org/ghc/#compare/ca00def1d7093d6b5b2a937ddfc8a01c152038... has links to the build logs of either build; there I could find that information.

That might be (part) of the problem. But if it is, it is even worse, as it would mean not only building the compiler got slower, but the compiler itself...

I can verify that the build itself is indeed slower. Validating the

current state of ghc-7.10 takes 19 minutes, whereas ghc-8.0 takes 25.5 minutes. This isn't entirely unexpected but the change is quite a bit larger than I had thought. It would be nice to know which commits are responsible.

btw, just recent experience on ARM64 (X-gene board):

bootstrapping 7.10.1 with 7.6.x took: ~120 minutes bootstrapping 8.0.1 RC2 with 7.10.1 took: ~446 minutes

both run as: ./configure; time make -j8

It would be interesting to have the time for bootstrapping 7.10.1 with 7.10.1 too, for comparison. Regards, Reid Barton