6841110bd6
`edata_cmp_summary_comp` is one of the very hottest functions, taking up 3% of all time spent inside Jemalloc. I noticed that all existing callsites rely only on the sign of the value returned by this function, so I came up with this equivalent branchless implementation which preserves this property. After empirical measurement, I have found that this implementation is 30% faster, therefore representing a 1% speed-up to the allocator as a whole. At @interwq's suggestion, I've applied the same optimization to `edata_esnead_comp` in case this function becomes hotter in the future.
jemalloc is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support. jemalloc first came into use as the FreeBSD libc allocator in 2005, and since then it has found its way into numerous applications that rely on its predictable behavior. In 2010 jemalloc development efforts broadened to include developer support features such as heap profiling and extensive monitoring/tuning hooks. Modern jemalloc releases continue to be integrated back into FreeBSD, and therefore versatility remains critical. Ongoing development efforts trend toward making jemalloc among the best allocators for a broad range of demanding applications, and eliminating/mitigating weaknesses that have practical repercussions for real world applications. The COPYING file contains copyright and licensing information. The INSTALL file contains information on how to configure, build, and install jemalloc. The ChangeLog file contains a brief summary of changes for each release. URL: https://jemalloc.net/