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

Postbox 5.0.9 - Powerful and flexible em...
Postbox is a new email application that helps you organize your work life and get stuff done. It has all the elegance and simplicity of Apple Mail, but with more power and flexibility to manage even... Read more
VueScan 9.5.61 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
DiskCatalogMaker 6.5.16 - Catalog your d...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast. Finder-like intuitive look and feel. Super-fast search algorithm. Can compress catalog data... Read more
TrailRunner 3.8.827 - Route planning for...
TrailRunner is the perfect companion for runners, bikers, hikers, and all people wandering under the sky. Plan routes on a geographical map. Import GPS or workout recordings and journalize your... Read more
Civilization VI 1.0.1 - Next iteration o...
Sid Meier’s Civilization VI is the next entry in the popular Civilization franchise. Originally created by legendary game designer Sid Meier, Civilization is a strategy game in which you attempt to... Read more
Chromium 55.0.2883.75 - 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 55.0.2883.75: Security fixes: High CVE-2016... Read more
Google Chrome 55.0.2883.75 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
VirtualBox 5.1.10 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
Pixa 1.1.9 - Quickly and easily organize...
Pixa is an image-organizing application. The new app functions well, is easy to use, and helps people organize their images quickly and easily on their computers. For those who prefer not to use the... Read more
VirtualBox 5.1.10 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more

Latest Forum Discussions

See All

Amateur Surgeon 4 Guide: Become the worl...
It's time to wield your trusty pizza cutter again, as Amateur Surgeon has returned with a whole fresh set of challenges (and some old, familiar ones, too). Starting anew isn't easy, especially when all you have at your disposal is a lighter, the... | Read more »
Le Parker: Sous Chef Extraordinaire (Ga...
Le Parker: Sous Chef Extraordinaire 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Telltale Games really is working on a Gu...
Telltale Games' next episodic adventure is indeed Guardians of the Galaxy. A document tied to the voice actors strike suggested that the project was in the work, but now we have direct confirmation following an announcement at the Game Awards that... | Read more »
Amateur Surgeon returns to iOS and Andro...
Amateur Surgeon and its two sequels disappeared from the App Store some time and it was sad days for all. But now, just in time for the holidays, the Adult Swim favorite makes its joyous return in the shape of Amateur Surgeon 4, a remake with... | Read more »
The best board games on mobile
Sometimes you need to ditch all of the high speed, high action games in favor of something a little more traditional. If you don't feel like parting ways from your mobile device, though, there are still plenty of ways to get that old-school fix.... | Read more »
The best Facebook Messenger Instant Game...
Facebook's new Instant Games is now here, meaning you can play games with your friends directly via Facebook. It's a fun new way to connect with friends, of course, but it's also proving to be a solid gaming experience in its own right, with a... | Read more »
You can now play game's on Facebook...
Facebook launched its new Instant Games platform in an exciting new attempt to engage its user base. As a result, you can now play a number of different games directly through Facebook Messenger. All of these games run with HTML5, meaning you play... | Read more »
Apollo Justice Ace Attorney (Games)
Apollo Justice Ace Attorney 1.00.00 Device: iOS Universal Category: Games Price: $.99, Version: 1.00.00 (iTunes) Description: Court Is Back In Session Star as rookie defense attorney, Apollo Justice, as he visits crime scenes,... | Read more »
KORG iWAVESTATION (Music)
KORG iWAVESTATION 1.0 Device: iOS Universal Category: Music Price: $19.99, Version: 1.0 (iTunes) Description: A revolutionary new world of sound.The Wave Sequence Synthesizer for iPad - KORG iWAVESTATION | Read more »
Don't Grind Guide: Tips for becomin...
Don’t Grind is a surprising, derpy little one touch game with fun hand-drawn graphics. The goal is simple -- get the high score without being chopped to bits. That can be tough when you’re not used to the game, and that’s compounded by the fact... | Read more »

Price Scanner via MacPrices.net

Holiday sale: Apple MacBook Airs available fo...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/128GB MacBook Air (MMGF2LL/A): $899 $100 off MSRP - 13″ 1.6GHz/... Read more
13-inch Silver Touch Bar MacBook Pro in stock...
Amazon has the new 2016 13″ 2.9GHz/256GB Silver Touch Bar MacBook Pro (MLVP2LL/A) in stock today and on sale for $1749 including free shipping. That’s $50 off MSRP, and it’s the lowest price... Read more
Parallels Toolbox 1.3 for Mac Offers 25 Singl...
Parallels has launched Parallels Toolbox 1.3 for Mac, an upgrade that adds five new utilities to the stand-alone application which was released in August and is available exclusively online at http... Read more
OWC Mercury Elite Pro Dual mini Ultra-Portabl...
OWC has introduced the new OWC Mercury Elite Pro Dual mini, a powerful yet ultra-portable dual-drive RAID solution. The new Mercury Elite Pro Dual mini packs phenomenal performance into a small... Read more
Clearance 13-inch Retina MacBook Pros availab...
B&H Photo has clearance 2015 13″ Retina Apple MacBook Pros available for up to $200 off original MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $... Read more
Roundup of 2016 13-inch 2.0GHz MacBook Pro sa...
B&H has the non-Touch Bar 13″ MacBook Pros in stock today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1449 $... Read more
New 13-inch 2.0GHz Space Gray MacBook Pro in...
Adorama has the new 13″ 2.0GHz Space Gray MacBook Pro (non-Touch Bar, MLL42LL/A) in stock for $1499 including a free 3-year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax... Read more
Finnair Adopts iOS Enterprise iPad Apps from...
Finnair and IBM have announced a first-of-its-kind agreement to utilize iOS enterprise apps from IBM to support the airline’s overall digital transformation. Finnair is focused on Asia-Europe traffic... Read more
Tech21 Launches Evo Go iPhone 7 Case Availabl...
Tech21 has announced the launch of the Evo Go case for Apple iPhone 7 and iPhone 7 Plus, exclusively at T-Mobile. Available online and at participating T-Mobile stores nationwide, Evo Go cases start... Read more
Apple Turns (RED) with More Ways to Join the...
In recognition of World AIDS Day, Apple is offering more ways than ever for customers to join (RED) in its mission to create an AIDS-free generation. Apple is the worlds largest corporate contributor... Read more

Jobs Board

*Apple* Retail - Multiple Positions- Chicago...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Hardware Design Validation Engineer - *Apple...
The Apple Watch team is looking for a Hardware Design Validation Engineer. This person will be part of the Apple Watch hardware team with responsibilities for Read more
SW Engineer *Apple* TV Frameworks - Apple I...
The Apple TV team is looking for a software...create features that reflect the look and feel of Apple TV. Description: Were looking for someone who is Read more
*Apple* Retail - Multiple Positions- Greenwi...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Brand Ambassador (Macy's) - The...
…(T-ROC), is proud of its unprecedented relationship with our partner and client, APPLE ,in bringing amazing" APPLE ADVOCATES"to "non" Apple store locations. Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.