Thread (62 messages) flat view 62 messages, 25 authors, 2016-06-15

Re: [RFC] Convert builin-mailinfo.c to use The Better String Library.

From: Andreas Ericsson <hidden>
Date: 2016-06-15 22:43:34

Wincent Colaiuta wrote:
El 7/9/2007, a las 13:54, Andreas Ericsson escribió:
quoted
Johannes Schindelin wrote:
quoted
Hi,
On Fri, 7 Sep 2007, Andreas Ericsson wrote:
quoted
Wincent Colaiuta wrote:
quoted
El 7/9/2007, a las 2:21, Dmitry Kakurin escribi?:
quoted
I just wanted to get a sense of how many people share this "Git 
should
be in pure C" doctrine.
Count me as one of them. Git is all about speed, and C is the best 
choice
for speed, especially in context of Git's workload.
Nono, hand-optimized assembly is the best choice for speed. C is just
a little more portable ;-)
I have a buck here that says that you cannot hand-optimise assembly 
(on modern processors at least) as good as even gcc.

http://www.gelato.unsw.edu.au/archives/git/0504/1746.html

I win. Donate $1 to FSF next time you get the opportunity ;-)
Well, you picked a very specific algorithm amenable to that kind of 
optimization: small, manageable, with a minimal and well-defined 
performance critical section that could be written in assembly. Note how 
a good chunk of the implementation was still in C. At most I'd give you 
75 cents for that one. ;-)
Yes, but that's what I said in the original email as well. C is just so
much more pleasant to write in that the only place you'd (sanely) use
asm is in exactly these tight loops, where the code is likely to be used
and reused until the algorithm it describes is no longer a viable option
for doing what it was originally designed to do.

It still proves the point though, as surely as n+1 > n for any value of n:
Hand-optimized assembly is faster than compiler-optimized C code.

It might be harder to do properly on some architectures than others (RISC
comes to mind), but it's still possible.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help