Re: cc-mode fontification feels random

[Ergus]

Going a bit more into this. And reconsidering tree-sitter.

As there is already a tree-sitter module package with some interesting
functionalities. (I know Eli didn't like some details in it's
implementation)

But maybe it is a good time to try to disable the cc-mode font-locking
(I don't actually know if it is possible to do that), and repeat the
scrolling benchmark only with the tree-sitter-mode and
tree-sitter-hl-mode enabled?

Just to see how it compares and how much of that approach is useful?



On Fri, Jun 11, 2021 at 03:57:10PM -0400, Stefan Monnier wrote:
> > Will Emacs 27.2 do?  If you must see results from an optimized build
> > of Emacs 28, I'll have to build one first.
>
> As mentioned, mine was not an optimized build, on the contrary.
>
> > > FWIW, I ran this same test with `sm-c-mode` (which should handle `xdisp.c`
> > > about as well as CC-mode, but solves an easier problem since it doesn't
> > > try to handle as much of C as CC-mode does (e.g. no support for K&R, no
> > > highlighting of types), nor does it try to handle C++, Java, ...), and
> > > most of the times for it are between 0.02 and 0.04.
> >
> > That is much better, but still too slow, IMO.  Think: it's the time
> > that it takes us to fontify a single windowful, only a couple of
> > dozens of lines.  Why does it take so long?
>
> For comparison, here it is for lisp/subr.el: it seems actually slightly
> slower than what I for with xdisp.c when using sm-c-mode.
>
>
>        Stefan
>
>
> 0.075539393
> 0.030856317
> 0.040824289
> 0.029961978
> 0.012222597
> 0.020277377
> 0.08354889
> 0.027791121
> 0.040834603
> 0.029304419
> 0.040401518
> 0.042230931
> 0.041249748
> 0.041759172
> 0.022928028
> 0.088205301
> 0.01791448
> 0.039915906
> 0.041701691
> 0.036885006
> 0.037948645
> 0.039082061
> 0.03723824
> 0.090796121
> 0.021685216
> 0.040341389
> 0.041098352
> 0.012256459
> 0.038770756
> 0.047087185
> 0.036423884
> 0.04461722
> 0.082821279
> 0.02936458
> 0.038498799
> 0.029450549
> 0.039748644
> 0.037981817
> 0.041704413
> 0.03614839
> 0.040829019
> 0.03792122
> 0.088297379
> 0.031529965
> 0.038930449
> 0.035313203
> 0.040872462
> 0.040254486
> 0.043807937
> 0.037344524
> 0.041937701
> 0.086986891
> 0.02128011
> 0.038679053
> 0.037372497
> 0.042372958
> 0.045191831
> 0.026552158
> 0.038718167
> 0.040198771
> 0.086453442
> 0.020748667
> 0.036524354
> 0.038769191
> 0.036234863
> 0.0399449
> 0.040732675
> 0.039041865
> 0.037608296
> 0.078606241
> 0.022010691
> 0.03774944
> 0.028604627
> 0.040171841
> 0.039866605
> 0.035715879
> 0.041613829
> 0.035701447
> 0.037601563
> 0.085249827
> 0.018101252
> 0.041692999
> 0.033016519
> 0.037679106
> 0.039894138
> 0.036513263
> 0.04271547
> 0.038203434
> 0.089595139
> 0.022256597
> 0.040981642
> 0.037780354
> 0.036986214
> 0.033088927
> 0.03626288
> 0.037085366
> 0.023201762
> 0.088236647
> 0.019961394
> 0.033811429
> 0.040647559
> 0.034390619
> 0.039764122
> 0.022225068
> 0.026550511
> 0.037590894
> 0.085617853
> 0.022528
> 0.040158828
> 0.039360065
> 0.015918947
> let: End of buffer