On 06/23/2010 11:10 AM, Shlomi Fish wrote: > Hi all, > > I've been using gcc-4.5.0 with -flto to build Freecell Solver ( > http://fc-solve.berlios.de/ ) - a C library for solving several types of > Solitaire games. During one commit to the svn repository, I got a major > slowdown in the performance of a benchmark. The attached text file explains > how to reproduce this. > > Here's what I know: > > 1. There doesn't appear to be a slowdown on my Acer x86-64 Dual Core laptop. > > 2. It's only on my Pentium 4 2.4 GHz machine. > > 3. gcc-4.4.3-2mnb2 is better in this respect, though naturally, without > gcc-4.5.0's -flto it produces slower binaries. > > 4. I'm running Mandriva GNU/Linux Cooker in case that matters. > > 5. I'm using Google's tcmalloc - > http://goog-perftools.sourceforge.net/doc/tcmalloc.html . > > Can anyone shed some light on why this is the case? Do you have profile data? If not, I'd start with oprofile. Andrew.
