------- Comment #6 from whaley at cs dot utsa dot edu 2006-05-31 01:09 ------- Subject: Re: gcc 4 produces worse x87 code on all platforms than gcc 3
Yes, I agree it is an x86/x86_64 issue. I have not yet scoped the performance of any of the other architectures with gcc 4 vs. 3: since 90% of my users use an x86 of some sort, I can't switch to gcc 4 support until the x86 performance is reasonable. It seems the x87 performance always goes down with any big gcc change (bugzilla 4991 is a similar performance drop between 2.x and 3.0, though the issues are not the exact same), probably because its oddball 2-op assembler / x87 stack doesn't map well to the more sane ISAs, which all compiler guys strongly prefer :) Thanks, Clint -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27827
