------- Comment #17 from whaley at cs dot utsa dot edu 2006-06-25 13:17 ------- OK, thanks for the reply. I will assume gcc 4 won't be fixed in the near future. My guess is this will make icc an easier compiler for users, which I kind of hate, which is why I worked as much as I did on this report . . .
I hope you will consider adding the mmbench4s.tar.gz attachment above (the one that runs both single and double precision) to the gcc regression tests. Notice that it caught this problem between 3 and 4, as well as a similar fp performance drop between gcc 2 and 3 (bugzilla 4991). The kernel here is typical of those used in ATLAS, which is used by hundreds of thousands of people worldwide. I believe these kernels are also typical of pretty much any register blocked fp code, so having them in the regression tests may help other open source fp packages (eg, fftw, etc) as well. Notice that closed-source alternatives that ship binaries do not face this challenge, so that having the compiler drop between releases gives them an advantage, and can drive HPC users (where performance dictates everything) to proprietary solutions. Thanks, Clint -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27827