[Bug fortran/30388] New: gfortran42 is slower than g77 3.4 about 10%

["chat95 at mac dot com" <gcc-bugzilla at gcc dot gnu dot org>]

1. download http://accc.riken.jp/HPC/HimenoBMT/Load_module/himenoBMTxp_m.lzh
% wget http://accc.riken.jp/HPC/HimenoBMT/Load_module/himenoBMTxp_m.lzh
2. extract with lha
% lha x himenoBMTxp_m.lzh 
himenobmtxp_m.f - Melted   :  o
3. apply following patch:
--- himenobmtxp_m.f~    Mon Jan  7 13:54:48 2002
+++ himenobmtxp_m.f     Sat Jan  6 09:02:22 2007
@@ -39,7 +39,6 @@
 C "use portlib" statement on the next line is for Visual fortran
 C to use UNIX libraries. Please remove it if your system is UNIX.
 C -------------------
-      use portlib
       IMPLICIT REAL*4(a-h,o-z)
 C
 C      PARAMETER (mimax=513,mjmax=257,mkmax=257)

4. compile with gfortran42 and g77-34.
% g77-34 -O -o himenobmtxp_m himenobmtxp_m.f
% ./himenobmtxp_m
  mimax= 257 mjmax= 129 mkmax= 129
  imax= 256 jmax= 128 kmax= 128
  Start rehearsal measurement process.
  Measure the performance in 3 times.
   MFLOPS:  421.095337  time(s):  0.976774991  0.00169381942
 Now, start the actual measurement process.
 The loop will be excuted in 184 times.
 This will take about one minute.
 Wait for a while.
  Loop executed for  184 times
  Gosa :  0.00126111682
  MFLOPS:  431.486053  time(s):  58.4661865
  Score based on Pentium III 600MHz :  5.20866823
PAUSE  statement executed
To resume execution, type go.  Other input will terminate the job.

STOP
% gfortran42 -O -o himenobmtxp_m himenobmtxp_m.f
himenobmtxp_m.f:111.72:

      pause                                                             
                                                                       1
Warning: Obsolete: PAUSE statement at (1)
% ./himenobmtxp_m
  mimax=         257  mjmax=         129  mkmax=         129
  imax=         256  jmax=         128  kmax=         128
  Start rehearsal measurement process.
  Measure the performance in 3 times.
   MFLOPS:   190.3127       time(s):   2.161261      1.6937795E-03
 Now, start the actual measurement process.
 The loop will be excuted in          83  times.
 This will take about one minute.
 Wait for a while.
  Loop executed for           83  times
  Gosa :  1.4101295E-03
  MFLOPS:   372.9143       time(s):   30.51566    
  Score based on Pentium III 600MHz :   4.501622    
PAUSE
To resume execution, type go.  Other input will terminate the job.

5 result:
g77-34 MFLOPS: 431.486053
gfortran MFLOPS: 372.9143

% g77-34 -v
Reading specs from
/usr/local/lib/gcc/i386-portbld-freebsd6.1/3.4.6/gcc/i386-portbld-freebsd6.1/3.4.6/specs
Configured with: ./..//gcc-3.4.6/configure --disable-nls --with-system-zlib
--with-libiconv-prefix=/usr/local --program-suffix=34
--libdir=/usr/local/lib/gcc/i386-portbld-freebsd6.1/3.4.6
--with-gxx-include-dir=/usr/local/lib/gcc/i386-portbld-freebsd6.1/3.4.6/include/c++/
--infodir=/usr/local/info/gcc34 --prefix=/usr/local i386-portbld-freebsd6.1
Thread model: posix
gcc version 3.4.6 [FreeBSD]

% gfortran42 -v
Using built-in specs.
Target: i386-portbld-freebsd6.1
Configured with: ./..//gcc-4.2-20070102/configure --disable-nls
--with-system-zlib --with-libiconv-prefix=/usr/local --with-gmp=/usr/local
--program-suffix=42 --libdir=/usr/local/lib/gcc-4.2.0
--with-gxx-include-dir=/usr/local/lib/gcc-4.2.0/include/c++/
--infodir=/usr/local/info/gcc42 --disable-rpath --prefix=/usr/local
i386-portbld-freebsd6.1
Thread model: posix
gcc version 4.2.0 20070102 (prerelease)


-- 
           Summary: gfortran42 is slower than g77 3.4 about 10%
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: chat95 at mac dot com
 GCC build triplet: i386-portbld-freebsd6.1
  GCC host triplet: i386-portbld-freebsd6.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30388