TweetFollow Us on Twitter

LS FORTRAN 3.3
Volume9
Number11
Column TagJörg's Folder

Language Systems FORTRAN 3.3

Performance test & FORTRAN to C conversion

By Jörg Langowski, MacTech Magazine Regular Contributing Author

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

Since Absoft has just brought out a new Fortran compiler (see July column, MacFORTRAN 3.2), the competition wasn’t sleeping: as I told you in my last column, Language Systems has brought out version 3.3 of their Fortran. It’s now installed (I got it the day I sent off the last column) and here are the Benchmark figures. Note: All benchmark tests were run at optimization level 3 for the LS Fortran compiler and at level -O (i.e. basic optimizations but no loop unrolling and subroutine folding) for the Absoft compiler. First, the results of the Linpack program for LS Fortran 3.3:

Linpack performance, single precision

LSF 3.3 MacIIx 0.125 MFlops

Q700, 68030 code 1.33 MFlops

Q700, 68040 code 1.33 MFlops

These performances are exactly the same as for version 3.0.1. It is interesting that it makes no difference at all whether 68030 or 68040 code is generated; it seems that the Absoft compiler is still making better use of the 68040 specifics. For example, Absoft MacFortran v3.3 runs the same code at 1.30 MFlops on a Quadra 700 when 68030 code is generated (thus at the same speed as LS Fortran) and at 1.61 MFlops for native 68040 code, i.e. 25% faster.

Language Systems has added a faster transcendental function library for the 68040, however. Since the Linpack does not use transcendental functions, this feature is not tested. Another known program, the Savage benchmark, tests accuracy and speed of some built-in math functions (see listing). The results, comparing the latest versions of the LS and Absoft compilers:

Savage Benchmark (execution times and results)

LSF 3.3 MacIIx 3.60 s 2500.000

Q700, 68030 code 3.02 s 2500.000

Q700, 68040 code 1.80 s 2500.000

Absoft MacIIx 3.52 s 2499.886

extended precision 3.65 s 2500.000

Q700, 68030 code 3.23 s 2499.886

Q700, 68040 code 1.37 s 2477.244

Q700, double precision

68040 code 1.43 s 2500.000

One thing that is immediately evident is the shabby performance of the 68040 on 68030 code; the Quadra 700 is no faster here than a Mac IIx! But this comes as no surprise: the 68040 FPU has no transcendental functions and EXP, LOG, etc. must be emulated in software. The 68040 math libraries of both LS and Absoft Fortran are much faster than the Apple emulation. For Absoft on the 68040, you have to take care that you compile with the ‘double precision transcendentals’ option, on the 68040, or with the extended precision option on the 68030, otherwise precision really breaks down. On the 68030, two compilers have identical performance speed- and precision-wise on the Savage benchmark. On the 68040, Absoft again has the speed edge over LS Fortran by about 30%.

So it is fair to say that Absoft’s compiler still produces the fastest-running Fortran code for the 68040; however, when you port programs from other systems, you should be very careful in checking the numerical accuracy against known results. Or play it safe in any case by using default double or extended precision, which doesn’t slow down execution too much.

To save the honor of the Macintosh, one should say that on so-called ‘bigger’ systems you have similar problems: for instance, on a VAX or on a Silicon Graphics workstation you have to declare A double precision to get the correct answer of 2500.000.

It seems at the moment that the Fortran compilers for the Macintosh are at a stage where they have converged to their respective limits of performance, and both are very similar speed- and precision-wise except for Absoft’s higher speed on a 68040. On the other hand, LS Fortran is still the only compiler that creates code to run on systems without an FPU. I guess what one should expect next from Language Systems is that they work on their Macintosh interface, for instance it would be nice to have multiple output windows connected to Fortran units.

Fortran to C

For those of you who have inherited some thousand lines of Fortran code and want to port it to the Mac, there may still be another way to go than using one of those excellent Fortran compilers. Even though Fortran is much better than its reputation with some people (you just have to look at the code provided by Language Systems of Absoft for full Macintosh applications), you might prefer to put in the work of converting your whole program into C, or C++. It is true that you may can gain a lot in readability and maintainability this way; but that mountain of work rewriting the code

Well, if you want to give up your Fortran nostalgia and like the fast compile/test cycle that Think C offers (there is no Think Fortran), here is a program for you: f2c, a public domain Fortran-to-C translator that has been around on Unix systems for quite a while. Some time ago, Basil Duval from Switzerland took the time to convert this program to Think C and put the result into the public domain Info-Mac archives at Stanford. His README file explains what he did:

“IMPORTANT--- This file and the others are available via anonymous ftp on elpp1.epfl.ch.

f2c Conversion on the MAC

Basil P. Duval Jan 1992, EPFL/CRPP Bassenges 1015 Lausanne, Switzerland

(This software is submitted free of change and may not be sold)

Email: Duval@elpp1.epfl.ch

Subject

This note describes a port of f2c to the THINK C Mac environment. The program f2c and the libraries libI77 and libF77 were converted and fortran programs have been successfully translated and linked to form working applications. In this first port, the default THINK C standard "Glass Window" screen is used to perform user input and output.

Version converted

The version taken from the server research.att.edu the 9 jan 1992 and has the 30 december 1991 time stamp.

Environment

The main problem with the port from UNIX to the Mac has been the 32k limit on global variables present up to version 5 of THINK C. Version 4 of THINK C allows string variables to be placed in a separate section. by simply requesting this option in the project options, the global variables were reduced from 56k to 31.6k which is acceptable in the Mac environment. Thus the program could be linked and tested. This enabled other problems of the port to surface. The main problem is due to the confusion with short and long integers. Up to THINK C 4, short was always defined as 2 bytes. In particular this causes several bugs when using the "strn..." functions which expect a (long) integer and as the code arrived were only given a 2 byte (short). The last problem was to provide a simple user interface. THINK C provides a console library which emulates the UNIX style command line via the "ccommand" routine which has been used to provide a rudimentary, but serviceable, interface. A list of the files that were changed is provided and the details of each change are provided at the end of this note.

(details omitted-JL)

Enclosed is a complete translation of the source using THINK C 5.02 together with a test file temp.f and a test project. The application has been compiled and linked for a Mac with 68030 and 68882 FPU unit but with the projects this could easily be changed. I spend the time since you mailed me getting the latest version of the f2c and putting in the bits needed to make it fly on the Mac, and so this version is labelled May 1992.

Good luck. The C source code is not supposed to be easy to edit, but it does get you quite a long way from the Fortran.

Basil Duval 2 June 1992

PS:Language Systems Fortran together with MPW 3.2 is a great combination if you decide to stay in fortran. THINK C is however a great environment for the Mac....”

The ready-to-use f2c application will be on the source code disk; for space reasons we cannot distribute the full system. If you have Internet access, you can however get the files via ftp either from the address given in the README file (see above), or from the Info-Mac archives at sumex-aim.stanford.edu. The conversion of the Savage benchmark is enclosed as an example in Listing 2. Of course you could have done this better by hand - however when you’re dealing with 4000 lines of code, that’s another story. I’ll try my hands on one of the big programs I have here until the next column and tell you my experiences - but first I have to get familiar with Think C, which I have never seriously used, believe it or not. Until then.

Listing 1: Savage Benchmark
C SAVAGE BENCHMARK
 REAL*4 A
C
CSECNDS is a real*4 function that returns 
Cseconds and fractional seconds.  The value is
Cmodified by subtracting the supplied argument.
CIt acts as in the VMS FORTRAN Manual.
C
 real*4 SECNDS
 real*4 time
 write(*,*) 'Starting '
 time = SECNDS(0.0)
 DO 200 J=1,10
 A=1.0D0
 DO 100 I=1,2499
 A=TAN(ATAN(EXP(LOG(SQRT(A*A))))) + 1.0
100CONTINUE
200CONTINUE
 time = SECNDS(time)
 WRITE (*,10) A
10 FORMAT(' A=',F17.12)
 write(*,*) time,' seconds'
 PAUSE
 END
 
 REAL FUNCTION SECNDS(time)
 real time
 n = LONG(362)
 SECNDS = FLOAT(n)/60.0 - time
 END
Listing 2: Savage Benchmark, converted to C by the f2c translator

/*  -- translated by f2c (version of 23 May 1992  14:18:33).
   You must link the resulting object file with the libraries:
 -lF77 -lI77 -lm -lc   (in that order)
*/

#include "f2c.h"

/* Table of constant values */

static integer c__9 = 9;
static integer c__1 = 1;
static real c_b4 = (float)0.;
static integer c__4 = 4;

/* !MP inlines.f */
/* SAVAGE BENCHMARK */
/* Main program */ MAIN__()
{
    /* Format strings */
    static char fmt_10[] = "(\002 A=\002,f17.12)";

    /* Builtin functions */
    integer s_wsle(), do_lio(), e_wsle();
    double sqrt(), log(), exp(), atan(), tan();
    integer s_wsfe(), do_fio(), e_wsfe();

    /* Local variables */
    static real time, a;
    static integer i, j;
    extern doublereal secnds_();

    /* Fortran I/O blocks */
    static cilist io___1 = { 0, 6, 0, 0, 0 };
    static cilist io___6 = { 0, 6, 0, fmt_10, 0 };
    static cilist io___7 = { 0, 6, 0, 0, 0 };


/* SECNDS is a real*4 function that returns */
/* seconds and fractional seconds.  The value is */
/* modified by subtracting the supplied argument. */
/* It acts as in the VMS FORTRAN Manual. */

    s_wsle(&io___1);
    do_lio(&c__9, &c__1, "Starting\311", 9L);
    e_wsle();
    time = secnds_(&c_b4);
    for (j = 1; j <= 10; ++j) {
      a = (float)1.;
      for (i = 1; i <= 2499; ++i) {
        a = tan(atan(exp(log(sqrt(a * a))))) + (float)1.;
/* L100: */
      }
/* L200: */
    }
    time = secnds_(&time);
    s_wsfe(&io___6);
    do_fio(&c__1, (char *)&a, (ftnlen)sizeof(real));
    e_wsfe();
    s_wsle(&io___7);
    do_lio(&c__4, &c__1, (char *)&time, (ftnlen)sizeof(real));
    do_lio(&c__9, &c__1, " seconds", 8L);
    e_wsle();
} /* MAIN__ */

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

CrossOver 14.1.6 - Run Windows apps on y...
CrossOver can get your Windows productivity applications and PC games up and running on your Mac quickly and easily. CrossOver runs the Windows software that you need on Mac at home, in the office,... Read more
Printopia 2.1.14 - Share Mac printers wi...
Run Printopia on your Mac to share its printers to any capable iPhone, iPad or iPod Touch. Printopia will also add virtual printers, allowing you to save print-outs to your Mac and send to apps.... Read more
Google Drive 1.24 - File backup and shar...
Google Drive is a place where you can create, share, collaborate, and keep all of your stuff. Whether you're working with a friend on a joint research project, planning a wedding with your fiancé, or... Read more
Chromium 45.0.2454.85 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. Version 45.0.2454.85: Note: Does not contain the "... Read more
OmniFocus 2.2.5 - GTD task manager with...
OmniFocus helps you manage your tasks the way that you want, freeing you to focus your attention on the things that matter to you most. Capturing tasks and ideas is always a keyboard shortcut away in... Read more
iFFmpeg 5.7.1 - Convert multimedia files...
iFFmpeg is a graphical front-end for FFmpeg, a command-line tool used to convert multimedia files between formats. The command line instructions can be very hard to master/understand, so iFFmpeg does... Read more
VOX 2.6 - Music player that supports man...
VOX is a beautiful music player that supports many filetypes. The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features and support for all... Read more
Box Sync 4.0.6567 - Online synchronizati...
Box Sync gives you a hard-drive in the Cloud for online storage. Note: You must first sign up to use Box. What if the files you need are on your laptop -- but you're on the road with your iPhone? No... Read more
Carbon Copy Cloner 4.1.4 - Easy-to-use b...
Carbon Copy Cloner backups are better than ordinary backups. Suppose the unthinkable happens while you're under deadline to finish a project: your Mac is unresponsive and all you hear is an ominous,... Read more
OmniGraffle Pro 6.3.1 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more

Rock(s) Rider - HD Edition (Games)
Rock(s) Rider - HD Edition 1.0.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.0 (iTunes) Description: *** PLEASE NOTE: Compatible with iPhone 4s, iPad 2, iPad mini, iPod touch (5th generation) or newer *** Do you... | Read more »
Rebuild 3: Gangs of Deadsville (Games)
Rebuild 3: Gangs of Deadsville 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: It's been a few years since the zombpocalypse turned the world's cities into graveyards and sent the few... | Read more »
Power Ping Pong (Games)
Power Ping Pong 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Do you wield your bat with zen-like focus or do your balls of fury give you a killer spin? Table tennis goes mobile with a... | Read more »
Z.O.N.A Project X (Games)
Z.O.N.A Project X 1.00 Device: iOS Universal Category: Games Price: $1.99, Version: 1.00 (iTunes) Description: Z.O.N.A Project X - shooter in the post-apocalyptic world. | Read more »
Trick Shot (Games)
Trick Shot 1.0.6 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0.6 (iTunes) Description: A game where all you have to do is throw a ball into a box, simple? Trick Shot is a minimalist physics puzzler with 90 levels... | Read more »
Goat Simulator MMO Simulator (Games)
Goat Simulator MMO Simulator 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: ** IMPORTANT - SUPPORTED DEVICESiPhone 4S, iPad 2, iPod Touch 5 or better.** Coffee Stain Studios brings next-gen... | Read more »
Worms™ 4 (Games)
Worms™ 4 1.02 Device: iOS Universal Category: Games Price: $4.99, Version: 1.02 (iTunes) Description: The latest instalment in the worldwide mega hit franchise! Coming soon to iPhone, iPad and iPod touch. When the guys and girls at... | Read more »
The Deer God (Games)
The Deer God 1.0 Device: iOS Universal Category: Games Price: $6.99, Version: 1.0 (iTunes) Description: 30% off launch sale!!! “It can be a struggle, but it's all worth it when you're shooting fire out your antlers.” Kotaku “The... | Read more »
AppSpy's Patreon campaign kicks off
Occasionally you'll see us use AppSpy's videos here on 148Apps to support an article we've written. That's because we're part of Steel Media, and AppSpy is Steel's video arm, so we're all part of one happy family. [Read more] | Read more »
We're Sorry to Report that Moonrise...
Moonrise is a very promising-looking, Pokemon-esque monster collecting and battling game that we were really looking forward to reviewing, but unfortunately it looks like that's never going to happen. [Read more] | Read more »

Price Scanner via MacPrices.net

Will You Buy An iPad Pro? – The ‘Book Mystiqu...
It looks like we may not have to wait much longer to see what finally materializes as a new, larger-panel iPad (Pro/Plus?) Usually reliable Apple product prognosticator KGI Securities analyst Ming-... Read more
eFileCabinet Announces SMB Document Managemen...
Electronic document management (EDM) eFileCabinet, Inc., a hosted solutions provider for small to medium businesses, has announced that its SecureDrawer and eFileCabinet Online services will be... Read more
WaterField Designs Unveils American-Made, All...
San Francisco’s WaterField Designs today unveiled their all-leather Cozmo 2.0 — an elegant attach laptop bag with carefully-designed features to suit any business environment. The Cozmo 2.0 is... Read more
Apple’s 2015 Back to School promotion: Free B...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
128GB MacBook Airs on sale for $100 off MSRP,...
B&H Photo has 11″ & 13″ MacBook Airs with 128GB SSDs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 1.6GHz/128GB MacBook Air: $799.99, $100 off MSRP... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
The Apple Store has Apple Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.... Read more
27-inch 3.2GHz iMac on sale for $1679, save $...
B&H Photo has the 27″ 3.2GHz iMac on sale for $1679.99 including free shipping plus NY sales tax only. Their price is $120 off MSRP. Read more
Apple and Cisco Partner to Deliver Fast-Lane...
Apple and Cisco have announced a partnership to create a “fast lane” for iOS business users by optimizing Cisco networks for iOS devices and apps. The alliance integrates iPhone with Cisco enterprise... Read more
Apple offering refurbished 2015 13-inch Retin...
The Apple Store is offering Apple Certified Refurbished 2015 13″ Retina MacBook Pros for up to $270 (15%) off the cost of new models. An Apple one-year warranty is included with each model, and... Read more
Apple refurbished 2015 MacBook Airs available...
The Apple Store has Apple Certified Refurbished 2015 11″ and 13″ MacBook Airs (the latest models), available for up to $180 off the cost of new models. An Apple one-year warranty is included with... Read more

Jobs Board

*Apple* Desktop Analyst - KDS Staffing (Unit...
…field and consistent professional recruiting achievement. Job Description: Title: Apple Desktop AnalystPosition Type: Full-time PermanentLocation: White Plains, NYHot Read more
Simply Mac *Apple* Specialist- Repair Techn...
Simply Mac is the greatest premier retailer of Apple products expertise in North America. We're looking for dedicated individuals to provide personalized service and Read more
Simply Mac *Apple* Specialist- Service Repa...
Simply Mac is the greatest premier retailer of Apple products expertise in North America. We're looking for dedicated individuals to provide personalized service and Read more
*Apple* Desktop Analyst - KDS Staffing (Unit...
…field and consistent professional recruiting achievement. Job Description: Title: Apple Desktop AnalystPosition Type: Full-time PermanentLocation: White Plains, NYHot Read more
Simply Mac- *Apple* Specialist- Store Manag...
Simply Mac is the largest premier retailer for Apple products and solutions. We're looking for dedicated individuals with a passion to simplify and enhance the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.