On Sun, 24 Feb 2002, Dave Seff wrote: > I took gcc 2.95.3, 2.96-80 (current cooker version)
It is not. > It it obvious that gcc 2.95.3 creates code that is twice as fast as the > latter versions. I ran this test after reading this article: > http://www.cs.utk.edu/~rwhaley/ATLAS/gcc30.html That "atlas problem" should be fixed in 3.0.4-2mdk. Jan Hubicka, who made the patch, had to say on the gcc mailing-list: "There was nothing wrong with the scheduler and the analysis on page are somewhat missleading. Real problem was that gcc "forgotten" about posibility of using memory operand in certain cases of commutative i387 fp instructions requiring one additional register. (this happent as result of two independent major change sin the compiler) This register is not available in the loop curefully written for 8 registers and causes the performance drop." BTW, the patch also helps the P4 FPU, for that particular case... Bye, Gwenole.
