This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug fortran/30388] gfortran42 is slower than g77 3.4 about 10%
- From: "chat95 at mac dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 6 Jan 2007 00:38:07 -0000
- Subject: [Bug fortran/30388] gfortran42 is slower than g77 3.4 about 10%
- References: <bug-30388-11045@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #3 from chat95 at mac dot com 2007-01-06 00:38 -------
% gfortran42 -o himenobmtxp_m.gfortran42 -O2 -ffast-math -finline-functions
-fomit-frame-pointer -funroll-loops -fexpensive-optimizations himenobmtxp_m.f
% ./himenobmtxp_m.gfortran42
mimax= 257 mjmax= 129 mkmax= 129
imax= 256 jmax= 128 kmax= 128
Start rehearsal measurement process.
Measure the performance in 3 times.
MFLOPS: 194.9637 time(s): 2.109703 1.6937795E-03
Now, start the actual measurement process.
The loop will be excuted in 85 times.
This will take about one minute.
Wait for a while.
Loop executed for 85 times
Gosa : 1.4063698E-03
MFLOPS: 391.9939 time(s): 29.72989
Score based on Pentium III 600MHz : 4.731940
PAUSE
To resume execution, type go. Other input will terminate the job.
% g77-34 -o himenobmtxp_m.g77 -O2 -ffast-math -finline-functions
-fomit-frame-pointer -funroll-loops -fexpensive-optimizations himenobmtxp_m.f
% ./himenobmtxp_m.g77
mimax= 257 mjmax= 129 mkmax= 129
imax= 256 jmax= 128 kmax= 128
Start rehearsal measurement process.
Measure the performance in 3 times.
MFLOPS: 242.952499 time(s): 1.69298697 0.00169377949
Now, start the actual measurement process.
The loop will be excuted in 106 times.
This will take about one minute.
Wait for a while.
Loop executed for 106 times
Gosa : 0.00136957248
MFLOPS: 246.231003 time(s): 59.0223999
Score based on Pentium III 600MHz : 2.97236848
PAUSE statement executed
To resume execution, type go. Other input will terminate the job.
Summary:
g77-34 with -O : 431.486053 MFLOPS
g77-34 with -O2 -ffast-math -finline-functions -fomit-frame-pointer
-funroll-loops -fexpensive-optimizations
: 246.231003 MFLOPS
gfortran42 with -O : 372.9143 MFLOPS
gfortran42 with -O2 -ffast-math -finline-functions -fomit-frame-pointer
-funroll-loops -fexpensive-optimizations
: 391.9939 MFLOPS
gfortran42 with -O2 ... produced faster code than gfortran42 -O, but
slower than g77-34 with -O, but g77-34 with -O2 ... produces very slow
code.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30388