glibc BoF Wei Wu * Can b4 be used for glibc patches posted on libc-alpha? Joseph Myers * I didn't get a reply to my recent message to overseers about glibc commits not getting filed properly. * For glibc, we rely on marking bugs fixed as soon as fixed on master, for the automatic generation of the list of fixed bugs for NEWS (which only looks at FIXED bugs with the relevant milestone). Joseph Myers * Could we do Bugzilla triage better, especially making sure bugs that have been fixed are closed? This seems like a similar backlog issue to patch review. Jeff Law * We've run into situations where invoking a program via ld.so results in a different memory layout (particularly the relationship between the .bss and heap) is changed and as a result we end up unexpectedly changing malloc arenas due sbrk failure. Has anyone else stumbled over this and does it really matter, or this kind of use really only important for the testsuite? Wei Wu * lazyparser has handed over this account to MaskRay :) * Will glibc be happy with Clang buildability? The most important patch is to removal C nested functions https://sourceware.org/bugzilla/show_bug.cgi?id=27220 * (the patch has been up for several weeks now) Jonathan Wakely * there's an open libstdc++ bug I need to look at, where the wrong symbol from the DSO seems to be getting used. But it's not a glibc bug, it's something in my court. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100912 ------------------------------------------ Power PC BOF Questions: Christoph Müllner * You were mentioning a "single-line-patch" in the backend, that pushed the SPEC performance by more than 2%. Can you explain more details and/or give some pointers to this amazing patch? Jonathan Wakely * Should std::random_device use the power DARN instruction (ISA 3.0) to get a random number? We support using RDRAND and RDSEED on x86 Joseph Myers: * Any plans to add _Float16 support (to the psABIs and the GCC back end), such as was recently added for x86_64 and has been present for AArch64 for a long time? Power has conversion instructions between binary16 and wider floating-point formats (thought not yet direct arithmetic on binary16, I think). Pedro Caldeira * Hey ppl, about AI libraries, do you guys have an idea how better MMA performs for AI, for example, any benchmark result for OpenBLAS? Another one, is MMA available for Tensorflow already? Neal Gompa * I'd be curious if these POWER changes would make it so we don't get weird things with the defaults for ppc64le with boolean. For example, lots of apps break with AltiVec bool by default. --------------------------------------- * Alexander Potapenko How does call registers wiping perform compared to control-flow integrity instrumentation provided by Clang? * Alexander Potapenko Question: Clang performs locals initialization in the frontend. How is this done in GCC? Also, do you have any performance data for GCC-implemented auto-initialization? Jeremy Bennett Question: Does the register erasure work across longjump? Or C++ throwing exceptions