This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Do C++ signed types have modulo semantics?
- From: Ulrich Weigand <uweigand at de dot ibm dot com>
- To: stevenb at suse dot de (Steven Bosscher)
- Cc: gcc at gcc dot gnu dot org, dewar at adacore dot com (Robert Dewar), mark at codesourcery dot com (Mark Mitchell), VEKSLER at il dot ibm dot com (Michael Veksler), pkoning at equallogic dot com (Paul Koning), gdr at integrable-solutions dot net, nathan at codesourcery dot com
- Date: Tue, 28 Jun 2005 14:02:07 +0200 (CEST)
- Subject: Re: Do C++ signed types have modulo semantics?
Steven Bosscher wrote:
> Anyway, I've started a SPEC run with "-O2" vs. "-O2 -fwrapv". Let's see
> how big the damage would be ;-)
Please make sure to include a 64-bit target, where it actually makes any
difference. (I recall performance degradations of 20-30% in some
SPECfp cases from getting induction variable reduction wrong ...)
Bye,
Ulrich
--
Dr. Ulrich Weigand
Linux on zSeries Development
Ulrich.Weigand@de.ibm.com