This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Thoughts on LLVM and LTO
- From: Diego Novillo <dnovillo at redhat dot com>
- To: gcc at gcc dot gnu dot org
- Cc: Benjamin Kosnik <bkoz at redhat dot com>
- Date: Wed, 23 Nov 2005 07:32:52 -0500
- Subject: Re: Thoughts on LLVM and LTO
- References: <200511221817.jAMIH2Co014676@porkchop.devel.redhat.com>
On Tuesday 22 November 2005 13:17, Benjamin Kosnik wrote:
> What about compile-time performance?
>
Well, it's hard to say, I have not really used LLVM extensively. The only
real data I have is compile times for SPECint:
SPECint build times (secs)
-O2 -O3
GCC 4.1.0 (20051117) 354 398
LLVM 1.6 (-Wl,-native-cbe) 802 805
So there appears to be a factor of 2 slowdown in LLVM. However, I know
LLVM has a separate GCC invokation. It seems as if it emitted C code that
is then compiled with GCC (I'm using -Wl,-native-cbe).
I don't think this would be standard procedure in an integrated LLVM.
Chris, how would one compare compile times? Not using -Wl,-native-cbe
implies emitting bytecode, right?