As of bug 1326486, our clang toolchains for Linux and Windows are built with PGO. (Apologies to Mac users: that toolchain is cross-compiled.)
Under optimal conditions (Spidermonkey build, touch mfbt) I've seen 10-15% compile time improvements locally, but in more common scenarios the gains will be diluted by other parts of the system. Perfherder measured 5-9% improvements in CI. To pick up a new compiler: after the next time you update your tree, run `./mach bootstrap` or `cd ~/.mozbuild && /path/to/mach artifact toolchain --from-build linux64-clang`, or on Windows replace the last part with `win64-clang-cl`. Happy compiling! _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
