On Mon, May 16, 2016 at 8:53 PM, Benjamin Smedberg <benja...@smedbergs.us> wrote: > On Mon, May 16, 2016 at 8:47 AM, Henri Sivonen <hsivo...@hsivonen.fi> wrote: >> For clarification: Does this decision apply to 32-bit x86 Linux as >> well? (It would be sad to have to supply and maintain non-SSE2 x86 >> code paths just for Linux.) > > Nobody asked about that, so it's wasn't specifically included. ... > so the real question here is whether we want > to support distros that don't require SSE2?
So we now require SSE2 on * All x86_64 (since SSE2 is part of the x86_64 baseline) * 32-bit x86 Mac, which means just the plugin-container now that we no longer support 10.6, which was the last OS X version that ran on 32-bit hardware. * 32-bit x86 Windows. It seems that we are almost ready to require SSE2 for Mozilla-built Firefox for 32-bit x86 Linux. What do we need to do to reach a decision on that? That leaves Linux distro-shipped Firefox and *BSD ports. The combination of the lack of function-level instruction set options in LLVM and the inconvenience of per-function compilation units in Rust probably would naturally make *run-time* selection of SSE2 vs. non-SSE2 a "patches not even welcome" kind of thing. (At least until LLVM and then rustc get per-function instruction set options.) What do we need to do to reach a decision that it's indeed OK to treat *run-time* selection of SSE2 vs. non-SSE2 especially in Rust code as a "patches not even welcome" kind of thing, considering that this may lead to Linux distros shipping an 32-bit x86 "Firefox" with degraded performance relative to Mozilla-shipped 32-bit x86 Firefox? On Mon, May 16, 2016 at 9:14 PM, Ralph Giles <gi...@mozilla.com> wrote: > It's also not clear how many of the distros which technically target > i[345]86 actually function on non-SSE2 hardware. It's easy for > non-compliant binaries to slip in if there's no active testing for > this. Should we prepare a list of distros that already documentedly require SSE2 and then test the other ones on non-SSE2 hardware to see if they already de facto require SSE2, too? Who would do the testing? Does there exist computers whose GPU has OpenGL driver support in Ubuntu and Fedora but whose CPU doesn't have SSE2? Because if the GPU doesn't have OpenGL driver support, the llvmpipe seems to bring a SSE2 requirement. (Maybe such computers run LXDE instead of an OpenGL-composited environment anyway.) -- Henri Sivonen hsivo...@hsivonen.fi https://hsivonen.fi/ _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
