[Bug other/17028] New: Code Slowdown wth -freduce-all-givs in C++

["CaptainSifff at gmx dot de" <gcc-bugzilla at gcc dot gnu dot org>]

In the Man-page, you said you're interested in Code that runs slower, with  
-freduce-all-givs -fmove-all-movables. I encounter in my programm ca. 5%-10%  
slowdown. 
 
If it's interresting: Compilation of my programm with -fnew-ra makes the Code  
20%-30% slower 
 
 
I'm using glibc-2.3.2 
on a SuSE System. Kernel 2.6.8-rc4 
 
I couldn't attach the relevant preprocessed Source-files, due to the  
restrictions of your mailing-List.And I couldn't send to your mailing List 
because it filters the header of my ISP. If someone is interrested in working 
on this, he can mail me(CaptainSifff@gmx.de). The compressed source is 212 kB.   
 
Feel free to ask for further Information. 
 
 
Processing of Polygon.cpp produces this Console-Output: 
 
Lese Spezifikationen von /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/specs 
Konfiguriert mit: ../gcc-3.4.1/configure --host=i686-pc-linux-gnu  
--with-gnu-as --with-gnu-ld --with-system-zlib --enable-threads  
--enable-shared --prefix=/usr --with-cpu=i586 --with-arch=i586  
--with-tune=i586 
Thread-Modell: posix 
gcc-Version 3.4.1 
 /usr/libexec/gcc/i686-pc-linux-gnu/3.4.1/cc1plus -E -quiet -v -D_GNU_SOURCE  
Polygon.cpp -march=athlon-xp -mmmx -msse -m3dnow -ffast-math -funroll-loops  
-funswitch-loops -fpeel-loops -funit-at-a-time -ftracer -fweb -O2 -o  
Polygon.ii 
nicht vorhandenes Verzeichnis  
»/usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../i686-pc-linux-gnu/include«  
wird ignoriert 
#include "..." - Suche beginnt hier: 
#include <...> - Suche beginnt hier: 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../include/c++/3.4.1 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../include/c++/3.4.1/i686-pc-linux-gnu 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../include/c++/3.4.1/backward 
 /usr/local/include 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/include 
 /usr/include 
Ende der Suchliste. 
In Datei, eingefügt von Polygon.cpp:21: 
Polygon.h:33:1: Warnung: "M_PI" redefined 
In Datei, eingefügt von Polygon.h:28, 
                    von Polygon.cpp:21: 
/usr/include/math.h:323:1: Warnung: this is the location of the previous  
definition 
 /usr/libexec/gcc/i686-pc-linux-gnu/3.4.1/cc1plus -fpreprocessed Polygon.ii  
-quiet -dumpbase Polygon.cpp -march=athlon-xp -mmmx -msse -m3dnow -auxbase  
Polygon -O2 -version -ffast-math -funroll-loops -funswitch-loops -fpeel-loops  
-funit-at-a-time -ftracer -fweb -o Polygon.s 
GNU C++ version 3.4.1 (i686-pc-linux-gnu) 
        compiled by GNU C version 3.4.1. 
GGC-Heuristik: --param ggc-min-expand=64 --param ggc-min-heapsize=64348 
 as -V -Qy -o Polygon.o Polygon.s 
 
Processing of dreidstudiomaxloader.cpp produces this output 
 
g++ -v -save-temps -march=athlon-xp -O2 -mmmx -msse -m3dnow -ffast-math  
-funroll-loops -funswitch-loops -fpeel-loops -funit-at-a-time -ftracer -fweb  
dreidstudiomaxloader.cpp -I. 
Lese Spezifikationen von /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/specs 
Konfiguriert mit: ../gcc-3.4.1/configure --host=i686-pc-linux-gnu  
--with-gnu-as --with-gnu-ld --with-system-zlib --enable-threads  
--enable-shared --prefix=/usr --with-cpu=i586 --with-arch=i586  
--with-tune=i586 
Thread-Modell: posix 
gcc-Version 3.4.1 
 /usr/libexec/gcc/i686-pc-linux-gnu/3.4.1/cc1plus -E -quiet -v -I.  
-D_GNU_SOURCE dreidstudiomaxloader.cpp -march=athlon-xp -mmmx -msse -m3dnow  
-ffast-math -funroll-loops -funswitch-loops -fpeel-loops -funit-at-a-time  
-ftracer -fweb -O2 -o dreidstudiomaxloader.ii 
nicht vorhandenes Verzeichnis  
»/usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../i686-pc-linux-gnu/include«  
wird ignoriert 
#include "..." - Suche beginnt hier: 
#include <...> - Suche beginnt hier: 
 . 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../include/c++/3.4.1 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../include/c++/3.4.1/i686-pc-linux-gnu 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/../../../../include/c++/3.4.1/backward 
 /usr/local/include 
 /usr/lib/gcc/i686-pc-linux-gnu/3.4.1/include 
 /usr/include 
Ende der Suchliste. 
In Datei, eingefügt von 3dsMax.h:20, 
                    von dreidstudiomaxloader.cpp:28: 
Polygon.h:33:1: Warnung: "M_PI" redefined 
In Datei, eingefügt von Polygon.h:28, 
                    von 3dsMax.h:20, 
                    von dreidstudiomaxloader.cpp:28: 
/usr/include/math.h:323:1: Warnung: this is the location of the previous  
definition 
 /usr/libexec/gcc/i686-pc-linux-gnu/3.4.1/cc1plus -fpreprocessed  
dreidstudiomaxloader.ii -quiet -dumpbase dreidstudiomaxloader.cpp  
-march=athlon-xp -mmmx -msse -m3dnow -auxbase dreidstudiomaxloader -O2  
-version -ffast-math -funroll-loops -funswitch-loops -fpeel-loops  
-funit-at-a-time -ftracer -fweb -o dreidstudiomaxloader.s 
GNU C++ version 3.4.1 (i686-pc-linux-gnu) 
        compiled by GNU C version 3.4.1. 
GGC-Heuristik: --param ggc-min-expand=64 --param ggc-min-heapsize=64348 
 as -V -Qy -o dreidstudiomaxloader.o dreidstudiomaxloader.s

-- 
           Summary: Code Slowdown wth -freduce-all-givs in C++
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: other
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: CaptainSifff at gmx dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-linux-gnu
  GCC host triplet: i686-linux-gnu
GCC target triplet: i686-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17028