------- Comment #15 from zadeck at naturalbridge dot com 2007-10-05 20:17 ------- Subject: Re: [4.3 regression]: wrong code with -fforce-addr
kargl at gcc dot gnu dot org wrote: > ------- Comment #13 from kargl at gcc dot gnu dot org 2007-10-05 17:50 > ------- > (In reply to comment #9) > >>> Hope this helps. >>> >> Sure, I've got the problem. The problem is actually in RTL optimization, >> where >> dse1 pass removes wrong insn. >> >> Suprisingly, the problem is in line 61 of comunpack.f: >> >> --> bscale = 2.0**real(idrstmpl(2)) >> dscale = 10.0**real(-idrstmpl(3)) >> >> > > This meant for Manfred instead of Uros, but it does contain the > relevant info. Manfred, you told me elsewhere that you use -fforce-addr > to achieve better performance. Whoever wrote this code should be > flogged. idrstmpl is an INTEGER variable, and gfortran can generate > much faster code for integer exponents than calling __builtin_powf. > > Try changing the lines to > > bscale = 2.0**idrstmpl(2) > dscale = 10.0**(-idrstmpl(3)) > > This, of course, doesn't fix the underlying bug. > > > neither richi nor myself are able to reproduced the problem. ./xgcc -B. -O2 -march=pentium4 -c mova2i.c -DLINUX ./gfortran -fforce-addr -B. -B../i686-pc-linux-gnu/libgfortran/.libs -O2 - march=pentium4 -o main main.f comunpack.f rdieee.f gbytesc.f mova2i.o and i get the same thing with and without -fforce-addr -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33638
