So how long until we set up opt-in build time telemetry? ;) Andrew
----- Original Message ----- > On 3/28/14, 2:16 PM, Chris Peterson wrote: > > warp is Facebook's new C/C++ preprocessor, written by Walter Bright (in > > D, of course). They claim build time (not just preprocessing time) of > > 10% to 40%. > > > > https://code.facebook.com/posts/476987592402291/under-the-hood-warp-a-fast-c-and-c-preprocessor > > I have a patch at > https://hg.stage.mozaws.net/gecko-collab/rev/d6ea4c36aa65 that will > change the build system to measure different phases of compiler > execution. For each compile command, it essentially runs -E + > -fsyntax-only + -c as separate commands and measures the results. > > I'm not sure if isolating the run time of -E is sufficient to measure > the performance overhead of the preprocessor. But what I do know is that > the last time I ran this (a few months ago), mozilla-central's problem > was in AST generation and codegen, not preprocessor. I believe -E > processes were only a few ms on average (assuming SSD, which you should > all be using if you have a choice - MoCo employees have a choice) and > AST/codegen were an order of magnitude longer. > > I encourage people to play around with this patch to measure things. > Better yet, try to hook up Warp and see if it actually makes a > difference. If it does, then by all means let's integrate it into the > build system like we already do with ccache. > _______________________________________________ > dev-platform mailing list > [email protected] > https://lists.mozilla.org/listinfo/dev-platform > _______________________________________________ dev-platform mailing list [email protected] https://lists.mozilla.org/listinfo/dev-platform
