llvm dev - Apr 2009 - [LLVMdev] glibc 2.10 featuring new elf trick

Hi,

I just wanted to brought you attention to the glibc 2.10 changelog. Take a 
special attention to the bottom (to the 'Automatic use of optimized 
function' section). URL: http://udrepper.livejournal.com/20948.html
This seems to be a nice way to make fat binaries. Not in the apple lingo, 
but to make binaries with code optimized for different archs. This sounds 
great to, at least, bundle different versions of some functions like strlen 
and the likes.

Nuno

"Nuno Lopes" <nunoplopes at sapo.pt> writes:
> Hi,
Hello,
> I just wanted to brought you attention to the glibc 2.10 changelog. Take a 
> special attention to the bottom (to the 'Automatic use of optimized 
> function' section). URL: http://udrepper.livejournal.com/20948.html
> This seems to be a nice way to make fat binaries.
IMO, fat binaries should go away and be replaced by LLVM bitcode, with
code generation performed by the OS at load time. This would have many
advantages: the compatibility with all current and future
architectures would be guaranteed, the code could be optimized at load
time to take advantage of specific features of the host (and even user
preferences), link-time optimization could happen with dynamic
libraries too, executable files would be smaller, assertions and other
debugging features could be turned on and off by the user, etc.

(But thanks for the pointer, nevertheless)

Michel.

Hello, Michael
> IMO, fat binaries should go away and be replaced by LLVM bitcode, with
> code generation performed by the OS at load time. This would have many
> advantages: the compatibility with all current and future
> architectures would be guaranteed,
Unfortunately no, the IR obtained from languages like C, C++, etc is
not target neutral.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University