commit | 194ae3236d81cf16dc39b955efc1b9202b59d067 | [log] [tgz] |
---|---|---|
author | Rémy Oudompheng <remyoudompheng@gmail.com> | Sun Apr 14 08:16:13 2019 +0200 |
committer | Robert Griesemer <gri@golang.org> | Tue Nov 12 05:18:25 2019 +0000 |
tree | 246ff4032a9c72642e78782c018abc18d8a5e749 | |
parent | b8cb75fb17511538524ac304abe68e62699c4e23 [diff] |
math/big: implement recursive algorithm for division The current division algorithm produces one word of result at a time, using 2-word division to compute the top word and mulAddVWW to compute the remainder. The top word may need to be adjusted by 1 or 2 units. The recursive version, based on Burnikel, Ziegler, "Fast Recursive Division", uses the same principles, but in a multi-word setting, so that multiplication benefits from the Karatsuba algorithm (and possibly later improvements). benchmark old ns/op new ns/op delta BenchmarkDiv/20/10-4 38.2 38.3 +0.26% BenchmarkDiv/40/20-4 38.7 38.5 -0.52% BenchmarkDiv/100/50-4 62.5 62.6 +0.16% BenchmarkDiv/200/100-4 238 259 +8.82% BenchmarkDiv/400/200-4 311 338 +8.68% BenchmarkDiv/1000/500-4 604 649 +7.45% BenchmarkDiv/2000/1000-4 1214 1278 +5.27% BenchmarkDiv/20000/10000-4 38279 36510 -4.62% BenchmarkDiv/200000/100000-4 3022057 1359615 -55.01% BenchmarkDiv/2000000/1000000-4 310827664 54012939 -82.62% BenchmarkDiv/20000000/10000000-4 33272829421 1965401359 -94.09% BenchmarkString/10/Base10-4 158 156 -1.27% BenchmarkString/100/Base10-4 797 792 -0.63% BenchmarkString/1000/Base10-4 3677 3814 +3.73% BenchmarkString/10000/Base10-4 16633 17116 +2.90% BenchmarkString/100000/Base10-4 5779029 1793808 -68.96% BenchmarkString/1000000/Base10-4 889840820 85524031 -90.39% BenchmarkString/10000000/Base10-4 134338236860 4935657026 -96.33% Fixes #21960 Updates #30943 Change-Id: I134c6f81a47870c688ca95b6081eb9211def15a2 Reviewed-on: https://go-review.googlesource.com/c/go/+/172018 Reviewed-by: Robert Griesemer <gri@golang.org> Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Gopher image by Renee French, licensed under Creative Commons 3.0 Attributions license.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
Official binary distributions are available at https://golang.org/dl/.
After downloading a binary release, visit https://golang.org/doc/install or load doc/install.html in your web browser for installation instructions.
If a binary distribution is not available for your combination of operating system and architecture, visit https://golang.org/doc/install/source or load doc/install-source.html in your web browser for source installation instructions.
Go is the work of thousands of contributors. We appreciate your help!
To contribute, please read the contribution guidelines: https://golang.org/doc/contribute.html
Note that the Go project uses the issue tracker for bug reports and proposals only. See https://golang.org/wiki/Questions for a list of places to ask questions about the Go language.