------- Comment #18 from hjl at lucon dot org 2007-06-04 21:14 ------- (In reply to comment #12) > Maybe someone should timings without the second reassoc. > Jeff mentioned the loop optimizers cause new reassociations: > http://gcc.gnu.org/ml/gcc-patches/2005-12/msg00469.html > And Daniel Berlin agreed with him (but this was before a DCE was added): > http://gcc.gnu.org/ml/gcc-patches/2005-12/msg00473.html >
Here are SPEC CPU 2K -O2 -ffast-math differences between revision 125030 without the second reassoc and revision 125029 on Intel64: (r125030 w/o reassoc2 - r125029)/r125029 164.gzip -0.282686% 175.vpr -0.928613% 176.gcc -0.34774% 181.mcf -0.430339% 186.crafty 0.430192% 197.parser -0.231839% 252.eon -0.487013% 253.perlbmk -0.592417% 254.gap 0% 255.vortex -0.211775% 256.bzip2 -1.2024% 300.twolf 0.0389257% Est. SPECint_base2000 -0.344149% 168.wupwise -0.881057% 171.swim -0.690449% 172.mgrid 3.89688% 173.applu -4.26743% 177.mesa -2.82981% 178.galgel -2.04283% 179.art -2.65207% 183.equake -0.347222% 187.facerec 0.191791% 188.ammp -5.33402% 189.lucas 1.65726% 191.fma3d 0.586667% 200.sixtrack -0.405954% 301.apsi 1.47219% Est. SPECfp_base2000 -0.836636% -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32183