Messages in this thread | | | Subject | Re: [patch V3] lib: GCD: add binary GCD algorithm | From | James Bottomley <> | Date | Thu, 28 Apr 2016 10:22:50 -0700 |
| |
On Thu, 2016-04-28 at 19:43 +0800, zengzhaoxiu@163.com wrote: > From: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> > > Because some architectures (alpha, armv6, etc.) don't provide > hardware division, the mod operation is slow! Binary GCD algorithm > uses simple arithmetic operations, it replaces division with > arithmetic shifts, comparisons, and subtractions. > > I have compiled successfully with x86_64_defconfig and > i386_defconfig.
What's the reason for wanting to optimize this and thus have to maintain (and test) two separate code paths, which is a significant expense? As far as I can see, gcd() is mosly used in finding optimal clocks for operations, which is usually done at start of day and not time critical.
James
| |