[Help-glpk] RE: Building glpk with vs2008

[Meketon, Marc]

Very interesting.  This corresponds to Luiz's finding that MinGW (with
-O2) is twice as fast as VS2008 without -O2.

So I guess that the conclusion is to explicitly add the -O2 to the
VS2008 build.  And then MinGW would be about the same speed as VS2008.

[BTW, I have a special attachment to the dfl001 problem - thanks for
including that in the benchmark!]


-----Original Message-----
From: Andrew Makhorin [mailto:address@hidden 
Sent: Monday, December 08, 2008 5:26 AM
To: glpk xypron
Cc: Meketon, Marc; address@hidden; address@hidden
Subject: Building glpk with vs2008

Monday, December 8, 2008, 9:57:42 AM, you wrote:

> Hello Mark,

>> May I recommend to Andrew or Xypron that at least -O2 is set on for
the
>> VS2008 makefile?

> thank you for your recommendations

> Flag /O2 is described here
> http://msdn.microsoft.com/en-us/library/8f8h5cxt.aspx
> as a default setting for release builds.

> Flag /GL is described here
> http://msdn.microsoft.com/en-us/library/0zza0de8.aspx
> Some caveats do exist:
> "The format of files produced with /GL in the current version may not
> be readable by subsequent versions of Visual C++."

> I will test with these two flags.

> Best regards

> Xypron

I did not find the difference between /O2 and /Ox (please see some
benchmarks below). However, the code is about twice faster than without
any optimization flags.

(It is interesting to note that the number of simplex iterations is
the same in all cases.)

Andrew Makhorin

------------------------------------------------------------------------
Solver:     glpsol 4.34
Computer:   Intel Pentium 4 CPU 3GHz, 2GB of RAM
Platform:   Windows XP 5.1 Build 2600 Service Pack 3
Compiler:   Microsoft 32-bit C/C++ Optimizing Compiler
            Version 15.00.30729.01 for 80x86
Build:      w32/Build_GLPK_with_VC9.bat
Test set:   Netlib LP collection <ftp://ftp.netlib.org/lp/data/>
Cmd line:   glpsol --mps foobar.mps
------------------------------------------------------------------------
CFLAGS = /I. /DHAVE_CONFIG_H /nologo /W3

Problem    Iters   Time,s   Mem,Mb
d2q06c      5398     11.0     5.8
dfl001     38894    181.6    11.0
greenbeb    2595      3.7     5.3
pilot87     7952     53.8    12.2
------------------------------------------------------------------------
CFLAGS = /I. /DHAVE_CONFIG_H /nologo /W3 /O2

Problem    Iters   Time,s   Mem,Mb
d2q06c      5398      6.2     5.8
dfl001     38894    109.6    11.0
greenbeb    2595      2.0     5.3
pilot87     7952     31.2    12.2
------------------------------------------------------------------------
CFLAGS = /I. /DHAVE_CONFIG_H /nologo /W3 /Ox

Problem    Iters   Time,s   Mem,Mb
d2q06c      5398      6.2     5.8
dfl001     38894    109.8    11.0
greenbeb    2595      2.0     5.3
pilot87     7952     30.9    12.2
------------------------------------------------------------------------

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