Fw: [RE-SENDING]Re: MCSoC2013: to enhance embedded Linux for many-core system

["ETANI NORIKO" <noriko-e at fc dot ritsumei dot ac dot jp>]

-----Forwarded message-----
From: ETANI NORIKO <noriko-e@fc.ritsumei.ac.jp>
To: iant <iant@google.com>
Date: Sun, 16 Dec 2012 21:26:34 +0900 (JST)
Subject: [RE-SENDING]Re: MCSoC2013: to enhance embedded Linux for many-core system

Dear Sir,

Thank you for replying my e-mail.

This is an implementation issue for OpenCL or parallel computing environment for embedded many-core system with Linux. OpneCL has two computing components which are a host core and a computing core.

The reason why GCC is not available for a computing device of OpenCl is that a load address for a binary file must be specified by a developer. In a case of GCC, a load address for a binary file is specified by Linux system.

Of course, we can use GCC on a host core, and we can use MPFR and GMP. However, as long as we use LD to link object files and create a binary file for a computing device core, we cannot use MPFR and GMP.

Here, we would like to ask you as follows:
1) Can LD have a function to link MPFR and GMP like GCC?
Or
2) MPFR and GMP are installed in GCC with GCC toolchain. Can MPFR and GMP be created as static libraries independent of GCC？

Best Regards,
Noriko Etani


-----Original message-----
From:Ian Lance Taylor <iant@google.com>
To:noriko-e@fc.ritsumei.ac.jp
Cc:gcc <gcc@gcc.gnu.org>
Date:Tue, 11 Dec 2012 17:45:37 -0800
Subject:Re: MCSoC2013: to enhance embedded Linux for many-core system

On Mon, Dec 10, 2012 at 2:00 AM, ETANI NORIKO
<noriko-e@fc.ritsumei.ac.jp> wrote:
>
> We have been developing many-core system in a program of摘xtremely Low-power Circuits and Systems (Green IT Project)敗ponsored by New Energy and Industrial Technology Development Organization (NEDO) which is one of National Project in Japan.
>
> We of Ritsumeikan University team are engaged in developing high-level API for a parallel computing on device cores and the software developing environment for many-core system.
>
> Here, we found out two important issues for the future of embedded Linux as follows:
> 1. uClibc cannot support some functions which glibc can support.
> A embedded system is developed for a specific field, and requires some functions in glibc.
> 2. Math functions and full computing of float and double are supported with MPFR and GMP libraries installed into GCC.
> In many-core system, GCC is not available because a load address must be specified. LD links object files and creates a binary file. This LD cannot load MPFR and GMP libraries. So, a computing device in many-core system cannot use math functions and full computing of float and double.

You seem to be talking about issues that make it harder to run GCC, or
indeed any conventional program, on your many-core system.  Is that
really what is interesting here?  Why not run GCC on a conventional
system as a cross-compiler, generating code for your many-core system?

Ian