I'd love to see ffmpeg compared with ASM switched off - so we can actually see which is the better compiler of C code and produces the faster binaries - yes I know no one in their right mind would use these binaries on a real system but the results could be normalised against the ASM builds
A couple of interesting things I see:
1. In C-Ray, intel was faster with gcc 4.2, amd ends up faster with gcc 4.7/4.8.
2. In FLAC audio encoding, the stiuation is actually reversed (though the differences are smaller this time): amd start out on top end ends up at the bottom.
Now the question is why? I wish Phoronix had a big editorial staff...
But why didn't those changes also affect Intel systems the same way?
I think someone here once said that the CRay results were heavily linked with how aggressively the compiler was at inlining code (with more inlining = faster), so it's possible that affects each processor differently. (Differently sized caches, branch predictors, etc.)
Thanks a lot for this benchmarking, Michael. As a Gentoo user I know what to do.
But something must be done about the horrible assortments of colours, e.g. whenever red is used. I am aware (from other threads) it looks easier said than done but the current color assortment really impairs reading those graphs.
These tests oftne land in "Meh, whatever" category, at least for me.
I would like to see more thought-out in-depth tests.
For example, whole point fo using gcc-4.7x for me is -flto optimisation.
It would be nice to see what it can bring to the table when compiling programs from many sources and compilation units which are then linked into final library and/or executeable.
Of course, right programm to test this is not something like tar but something more complex.
Also it would be nice to see and compare used resources and final result during flto compilation and linking. flto has been notorious for eating memory and CPU cycles when compiling chrome or openoffice. It would be nice to see how much has this impact with gcc-4.5* - gcc-4.8*
Also, when finding regressions, it would be nice to go in-depth for their cause. Is error on the part of compiler, or simply program infrastructure misunderstood some compilers new feature, for example ?