Gentoo Archives: gentoo-dev

From: "C Bergström" <cbergstrom@×××××××××.com>
To: "Anthony G. Basile" <gentoo-dev@l.g.o>
Cc: llvm@g.o
Subject: Re: [gentoo-dev] New project: LLVM
Date: Fri, 19 Aug 2016 03:12:03
Message-Id: CAOnawYqzQjLYwLTF62mDw2DcW6eA2hhA-PFduQo9MOBWDtj3Vg@mail.gmail.com
In Reply to: Re: [gentoo-dev] New project: LLVM by Lei Zhang
1 I think you're getting a bit confused
2
3 libsupc++ is the default now, from GNU
4
5 libcxxabi is the bloated runtime from Apple
6
7 libcxxrt is the faster c++ runtime, PathScale+David Chisnall, which
8 PathScale and FreeBSD use by default. We don't need a version number
9 because it's pretty much rock solid stable for a while.
10 I'd encourage you to consider libcxxrt for at least the code size and
11 performance reasons. Build it and you'll see. Locally my unoptimized
12 libcxxrt.so is like 88K. How much is your libcxxabi (static and
13 shared)
14
15 88K /opt/enzo-2016-06-26/lib/6.0.983/x8664/64/libcxxrt.so
16 140K /opt/enzo-2016-06-26/lib/6.0.983/x8664/64/libcxxrt.a
17 // This seems larger than I remember and I need to check why.
18
19 https://github.com/pathscale/libcxxrt
20
21 On Fri, Aug 19, 2016 at 10:40 AM, Lei Zhang <zhanglei.april@×××××.com> wrote:
22 > 2016-08-19 10:07 GMT+08:00 <cbergstrom@×××××××××.com>:
23 >> That seems a lot like what we've already done. I guess a GSOC student is working on the libcxxabi piece.
24 >
25 > I am that GSoC student :)
26 >
27 > I'm currently trying to push libc++abi to replace libcxxrt as the
28 > default runtime: https://github.com/gentoo/gentoo/pull/2048
29 >
30 > The reason is I think libc++abi blends in more naturally with other
31 > LLVM components, and it has a clear version number as opposed to
32 > libcxxrt.
33 >
34 >> The only advantage to using our runtime, libcxxrt, is performance and code size.‎
35 >
36 > Honestly I don't know what essential difference these two libs have; I
37 > can't find any decent comparison of them on the internet. Do you have
38 > some real numbers to show the difference in performance and code size?
39 >
40 >
41 > Lei
42 >

Replies

Subject Author
Re: [gentoo-dev] New project: LLVM Luca Barbato <lu_zero@g.o>
Re: [gentoo-dev] New project: LLVM Lei Zhang <zhanglei.april@×××××.com>