9938a64ca9
This brings to newlib a performance improvement that we developed in Bionic libc. That change has been submitted for review to Bionic libc: https://android-review.googlesource.com/418279 A similar patch has been submitted for review in glibc: https://sourceware.org/ml/libc-alpha/2017-06/msg01143.html Patch written by Vikas Sinha and Sebastian Pop. The performance was measured on the bionic-benchmarks on a hikey (aarch64 8xA53) board. There was no performance change to the existing benchmark and a performance improvement on the new benchmark for memcmp on the unaligned side. The new benchmark has been submitted for review at https://android-review.googlesource.com/414860 The overall performance improves by 18% for the small data set 8 and the performance improves by 450% for the large data set 64k. The base is with the libc from /system/lib64. The bionic libc with this patch is in /data. hikey:/data # export LD_LIBRARY_PATH=/system/lib64 hikey:/data # ./bionic-benchmarks --benchmark_filter='BM_string_memcmp*' Run on (8 X 2.4 MHz CPU s) Benchmark Time CPU Iterations ---------------------------------------------------------------------- BM_string_memcmp/8 30 ns 30 ns 22955680 251.07MB/s BM_string_memcmp/64 57 ns 57 ns 12349184 1076.99MB/s BM_string_memcmp/512 305 ns 305 ns 2297163 1.56496GB/s BM_string_memcmp/1024 571 ns 571 ns 1225211 1.66912GB/s BM_string_memcmp/8k 4307 ns 4306 ns 162562 1.77177GB/s BM_string_memcmp/16k 8676 ns 8675 ns 80676 1.75887GB/s BM_string_memcmp/32k 19233 ns 19230 ns 36394 1.58695GB/s BM_string_memcmp/64k 36986 ns 36984 ns 18952 1.65029GB/s BM_string_memcmp_aligned/8 199 ns 199 ns 3519166 38.3336MB/s BM_string_memcmp_aligned/64 386 ns 386 ns 1810734 158.073MB/s BM_string_memcmp_aligned/512 1735 ns 1734 ns 403981 281.525MB/s BM_string_memcmp_aligned/1024 3200 ns 3200 ns 218838 305.151MB/s BM_string_memcmp_aligned/8k 25084 ns 25080 ns 28180 311.507MB/s BM_string_memcmp_aligned/16k 51730 ns 51729 ns 13521 302.057MB/s BM_string_memcmp_aligned/32k 103228 ns 103228 ns 6782 302.727MB/s BM_string_memcmp_aligned/64k 207117 ns 207087 ns 3450 301.806MB/s BM_string_memcmp_unaligned/8 339 ns 339 ns 2070998 22.5302MB/s BM_string_memcmp_unaligned/64 1392 ns 1392 ns 502796 43.8454MB/s BM_string_memcmp_unaligned/512 9194 ns 9194 ns 76133 53.1104MB/s BM_string_memcmp_unaligned/1024 18325 ns 18323 ns 38206 53.2963MB/s BM_string_memcmp_unaligned/8k 148579 ns 148574 ns 4713 52.5831MB/s BM_string_memcmp_unaligned/16k 298169 ns 298120 ns 2344 52.4118MB/s BM_string_memcmp_unaligned/32k 598813 ns 598797 ns 1085 52.188MB/s BM_string_memcmp_unaligned/64k 1196079 ns 1196083 ns 540 52.2539MB/s hikey:/data # export LD_LIBRARY_PATH=/data hikey:/data # ./bionic-benchmarks --benchmark_filter='BM_string_memcmp*' Run on (8 X 2.4 MHz CPU s) Benchmark Time CPU Iterations ---------------------------------------------------------------------- BM_string_memcmp/8 30 ns 30 ns 23209918 252.802MB/s BM_string_memcmp/64 57 ns 57 ns 12348447 1076.95MB/s BM_string_memcmp/512 305 ns 305 ns 2296878 1.56471GB/s BM_string_memcmp/1024 572 ns 571 ns 1224426 1.6689GB/s BM_string_memcmp/8k 4309 ns 4308 ns 162491 1.77109GB/s BM_string_memcmp/16k 9348 ns 9345 ns 74894 1.63285GB/s BM_string_memcmp/32k 18329 ns 18322 ns 38249 1.6656GB/s BM_string_memcmp/64k 36992 ns 36981 ns 18952 1.65045GB/s BM_string_memcmp_aligned/8 199 ns 199 ns 3513925 38.3162MB/s BM_string_memcmp_aligned/64 386 ns 386 ns 1814038 158.192MB/s BM_string_memcmp_aligned/512 1735 ns 1735 ns 402279 281.502MB/s BM_string_memcmp_aligned/1024 3204 ns 3202 ns 218761 304.941MB/s BM_string_memcmp_aligned/8k 25577 ns 25569 ns 27406 305.548MB/s BM_string_memcmp_aligned/16k 52143 ns 52123 ns 13522 299.769MB/s BM_string_memcmp_aligned/32k 105169 ns 105127 ns 6637 297.26MB/s BM_string_memcmp_aligned/64k 206508 ns 206383 ns 3417 302.835MB/s BM_string_memcmp_unaligned/8 282 ns 282 ns 2482953 27.062MB/s BM_string_memcmp_unaligned/64 542 ns 541 ns 1298317 112.77MB/s BM_string_memcmp_unaligned/512 2152 ns 2152 ns 325267 226.915MB/s BM_string_memcmp_unaligned/1024 4025 ns 4025 ns 173904 242.622MB/s BM_string_memcmp_unaligned/8k 32276 ns 32271 ns 21818 242.09MB/s BM_string_memcmp_unaligned/16k 65970 ns 65970 ns 10554 236.851MB/s BM_string_memcmp_unaligned/32k 131241 ns 131242 ns 5129 238.11MB/s BM_string_memcmp_unaligned/64k 266159 ns 266160 ns 2661 234.821MB/s
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.