TweetFollow Us on Twitter

Sep 90 Letters
Volume Number:6
Issue Number:9
Column Tag:Letters

A Call For Benchmarks

By Kirk Chase, Editor, MacTutor

Mouser Info Needed

David Landowne

Miami, FL

Help! I’ve been reading MacTutor for four years, great mag, but today I’m trying to track down a hot tip from the April 90 issue. In your Letter column, Greg Poole talks about the Mouser 1.2d5 and says it is available on AppleLink in the MacApp discussion folder. Soo I go to my local Link and in 20 minutes cannot find a MacApp folder or Mouser or anything with 1.2d5 in the software library. My host gets bored and says he’ll try later.

Do you have any further info or can you contact Greg Poole for me and find this browsing tool. It sounds like just what I need at my point in the learning curve.

While I have the line open, an answer to Mike Scanlin is

andi #0x8007
bpl  @1
ori  #0xFFF8
@1

Thanks and thanks for having such a great MacTutor.

[Mouser is now included in MacApp 2.0 which is available from APDA and on AppleLink, Developer Services:Macintosh Development Tool Discussions: MacApp Discussion:Mouser.-ed]

Benchmark Challenge

Walt Davis, Steve Bayer

Webster, TX

If you ask experienced programmers which language, C or Pascal, produces a faster implementation of a given algorithm on a given machine, we’d bet at least 9 out of 10 would choose C. Experienced programmers know C is closer to the native machine language, provides register variables, and is more flexible than Pascal. After all, wasn’t Unix written in C? Besides, Pascal is perceived as a higher-level language than C used mostly for teaching. Aren’t higher-level languages generally slower?

Imagine our surprise when we ran some simple comparison tests using Symantec’s THINK C 4.0 and THINK Pascal 2.0 compilers for the Mac. It all started over a discussion about the comparative performance of Case (Switch in C) and the If-Then_Else language constructs. Since we expected Case (or Switch) to be a specialized form of the If-Then-Else, we expected Case to be quicker and for the most part our results showed this to be true for both C and Pascal compilers. The code we used for our tests is summarized below:

{1}

Pascal

{If-Then-Else Test Procedure }
procedure TestIfThenElse;
var
 i, startT, stopT: longint;
 b: integer;
begin
 GetDateTime(startT);
 for i:= 1 to 1000000 do
 begin
 if b = 1 then
 begin
 end
 else if b = 2 then
 begin
 end
  
 else if b = 15 then
 begin
 end;
 end;
 GetDateTime(stopT);
 ShowElapsedTime(startT, stopT);
end;

{ Case Test Procedure }
procedure TestCase;
var
 b: integer;
 i, startT, stopT: longint;
begin
 GetDateTime(startT);
 for i := 1 to 1000000 do
 begin
 case b of
 1:
 begin
 end;
 2:
 begin
 end;
  
 15:
 begin
 end;
 otherwise
 end;
 end;
 GetDateTime(stopT);
 ShowElapsedTime(startT, stopT);
end;

/* 2 */

C

/* If-Then-Else Test Function */
TestIfThenElse() {
int b;
long i, startT, stopT;

GetDateTime(&startT)
for (i = 0; i < 1000000; i++) {
 if (b==1) {} else
 if (b==2) {} else
  
 if (b==15) {};
}
GetDateTime(&stopT);
ShowElapsedTime(startT, stopT);
}

/* Switch Test Procedure */
TestSwitch() {
int b;
long i, startT, stopT;

GetDateTime(&startT);
for (i = 0; i < 1000000; i++) {
 switch (b) {
 case (1):
 break;
 case (2):
 break;
  
 case (15):
 break;
 }
}
GetDateTime(&stopT);
ShowElapsedTime(startT, stopT);
}

The If-Then and Case/Switch constructs in the test procedures and functions compare the variable b with integer values from 1 through 15. We measured the time it took to complete one million loops for values of b ranging from 1 to 20. There were no Mac Toolbox calls within the loops so no conversion from C to Pascal was required, and we compiled all code with the math coprocessor option disabled. We ran identical tests on the Mac Plus, Mac SE, and Mac II models under Finder, not MultiFinder. Table 1 shows our results in tabular form and Figure 1 shows a chart of the results for the Mac Plus Tests.

Table 1. Time (seconds) To Execute If-Then-Else versus Case/Switch Procedures

Figure 1. Test Results For If-Then-Else versus Switch/Case on a Mac Plus

Our tests show a similar relationship between the If-Then-Else and Case constructs in Pascal and the If-Then-Else and Switch constructs in C. The surprising results of our tests is that, depending on the machine, it can take anywhere from 60% to over 100% longer to execute a particular language construct in C than it does in Pascal. These results really just point out the obvious; that the relative speed of a high-level language depends on the assembly language produced by the compiler and not the high-level language itself.

In closing, we would like to challenge MacTutor and its readers to repeat these tests using the Symantec compilers on similar hardware platforms to verify our results. Do these results hold for other compilers, e.g. MPW? How do other languages like Fortran and Modula-2 compare? Do these results hold for other language constructs besides the ones tested here?

SANE Bypass Help Needed

Martin E. Huber

Boulder, CO

I am a scientific/technical researcher and use the Macintosh for lengthy numerical simulations of physical systems. I would like to get every bit of speed I can out of the floating-point co-processor (FPU) and am not sure my current compiler uses it to its full potential. The accuracy provided by the 68881/68882 chips is more than sufficient for my needs the SANE standards are over-kill.

I have heard somewhere (I don’t remember where) that there are a few different ways programs on the Mac execute floating point operations. First, the FPU can be ignored altogether, in which case SANE uses the CPU for all operations. Second, if a FPU is present, SANE routines are used, but the routines use the FPU. Finally, the floating point operations can bypass SANE altogether and be passed directly to the FPU. Is this description accurate?

If so, I would like to find a compiler which bypasses SANE for ALL arithmetic functions (including add/subtract, multiply/divide), not just for the transcendental functions. Does such a beast exist? (I’ve heard that some compilers which make “direct” FPU calls still end up running through SANE.) Can you tell me which compiler provides the fastest running number-crunching code on a Mac with a FPU (in each of the languages Fortran, Pascal, Basic, and C, if possible), or at least where I might find such information? I haven’t seen any compilation of benchmark results lately. Thanks for any assistance you can provide.

Metrowerks Modula-2

Greg Galanos

Metrowerks, Inc.

The Trimex Bldg, Rte 11

Mooers, NY, 12958.

I would like to respond to Allen Stenger’s letter, which appeared in the July issue of MacTutor, by clarifying a certain number of technical points brought up with respect to the Metrowerks Modula-2 Professional Standalone Edition compiler. Before starting I would like to thank Allen for his perceptive comments.

The peculiar-looking code that Allen refers to, implemented through a jump table, is uniquely the runtime support necessary to implement functions not supported by the 68000 processor. All normal procedures are called in the usual method used on the Motorola processor family. (I will come back to this issue during the discussion on dynamic linking). Metrowerks Modula-2 PSE generates native 68000 (or 68020/030) code, the above being one of only two instances where jump tables are used. The second instance is in the treatment of CASE statements and this is due to change in a subsequent releases this year.

Allen is correct in stating that the debugger does not like anchored variables. The main reason is that when we upgraded the PSE compiler to correctly handle AVs to provide source-code compatibility with the MPW compiler, we forgot to upgrade the debugger to handle their display. However this will be fixed in the next release, due around the same time as this issue will appear.

A point of clarification on the rumored TML Modula-2 compiler, which was written by Bob Campbell and licensed to TML Systems for publishing. Unfortunately for reasons unknown, but certainly not because of the quality of the Campbell compiler, TML decided to withdraw the compiler from the marketplace and thus lost the distribution rights to the product.

Metrowerks decided that the Campbell compiler was an extremely well written MPW compiler and entered into a joint development and publishing agreement with Mr. Campbell last November. Since then, and until market introduction in April 1990, the developers have been working on bringing both the PSE and MPW compilers up to source-code compatibility (while the anchored variable display in the debugger went unnoticed).

On compiler speed, Allen mentioned that the PSE compiler is half as fast as the Sempersoft compiler. We have not been able to find the mentioned compiler on the market but this is an unfair comparison. The PSE compiler may take more time during the symbol file importation but this is due to the fact that we are giving the user a graphical progress report of the compilation pass and this certainly slows down imports because of the screen updating. This is not the case for an MPW tool.

We did however check compile times between the Modula-2 MPW Edition, MPW Pascal and MPW C and the following table displays the hand-checked results of compiling the TubeTest example program distributed with MPW by MacDTS.

MPW Edition MPW Pascal MPW C

6 6 11

(in seconds on a Mac-IIci, MPW 3.1, compiler versions 3.1)

These results lead us to believe that the Metrowerks compilers hold their own on compile speed when comparing apples with apples (no pun intended).

Dynamic Linking Explained

Now for the lengthiest part of this letter, clarifying bulky code. If anyone would care to examine an .obm file containing the object code produced by the PSE compiler, I’m sure they will notice that the code produced is short and sweet. The method used to produce a fast prototyping system in our case is called dynamic link-loading. This does not reduce compile time, but radically cuts link time through the use of dynamic links.

We use a program stack while your program is executing within the Metrowerks environment. The object files generated by the compiler are completely relocatable and need not be patched. They are merely ready to be loaded. Besides the main module, which is called to be executed at the highest level of the program stack, all modules that are directly or indirectly imported by the main program are loaded and linked with one important exception which is in the case of memory-resident modules.

A large percentage of the imported modules are already part of the resident Metrowerks shell. For instance FileIO and QuickDraw or any number of toolbox and OS managers are being used by the shell to implement the multi-window text editor, or the compiler parser/scanner. In the case where one of these modules is directly or indirectly imported by the main program the linker/loader sets up a dynamic link to the memory-resident module instead of reloading it from disk.

This permits high speed dynamic linking which provides fast compile, debug and execute cycles within the environment. When the main program completes execution, it is removed from memory along with the other imported modules that are not memory-resident. The actual implementation of the program stack is simply the following:

PROCEDURE Call (module: ARRAY OF CHAR;
           leaveLoaded: BOOLEAN; VAR   status: Status);

PROCEDURE ExecuteObmFile(name: ARRAY OF CHAR;
                         enterDebug: BOOLEAN);
VAR
  status :    Status;
BEGIN
...
  Call(name, FALSE, status);
 ...
END ExecuteObmFile;

The advantage of dynamic linking is fast turnaround time as well as the fact that your own finished application can also implement this scheme. The System.Call mechanism can be used by any program compiled with the PSE compiler. The advantage of a program stack call is that the stack is not limited to 32k segments. It may be as large as the memory available as long as the data and code size of an individual module either imported or importing is not larger than 32k each.

The tradeoff on dynamic linking is that because the nature of the link is dynamic we cannot, at this time, remove unused code (sometimes referred to as dead code) from the linked application without removing the System.Call facility. It is precisely this tradeoff that makes the produced application, and not the generated object code, larger than for instance an MPW produced application. We are currently investigating whether we will write an incremental linker or wait until Apple comes up with one.

However, this does not mean that Metrowerks Modula-2 PSE is not suitable for applications development, the proof of the pudding being that the entire Metrowerks Modula-2 Professional Standalone Edition bootstraps itself and is linked by PSE under the above mentioned dynamic linking scheme.

For those of you who do want the fast-prototyping capabilities of PSE but also want the linking capabilities of MPW, we suggest prototyping on PSE and delivering the final product on the Metrowerks MPW Edition compiler. These can be purchased separately or as a bundle for less than $300. Source-code compatibility between the two compilers gives anyone a reasonably priced solution to having the best of both worlds.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Backup and Sync 3.46 - File backup and s...
Backup and Sync (was 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... Read more
iClock 5.5 - Customizable menu bar clock...
iClock replaces the old Apple's default menu bar clock with more features, customization and increases your productivity. Features: Have your Apple or Google calendar instantly available from the... Read more
Garmin Express 6.18.0.0 - Manage your Ga...
Garmin Express is your essential tool for managing your Garmin devices. Update maps, golf courses and device software. You can even register your device. Update maps Update software Register your... Read more
MarsEdit 4.3.5 - Quick and convenient bl...
MarsEdit is a blog editor for OS X that makes editing your blog like writing email, with spell-checking, drafts, multiple windows, and even AppleScript support. It works with with most blog services... Read more
Xcode 11.0 - Integrated development envi...
Xcode includes everything developers need to create great applications for Mac, iPhone, iPad, and Apple Watch. Xcode provides developers a unified workflow for user interface design, coding, testing... Read more
DaisyDisk 4.8 - $9.99
DaisyDisk allows you to visualize your disk usage and free up disk space by quickly finding and deleting big unused files. The program scans your disk and displays its content as a sector diagram... Read more
VMware Fusion 11.5.0 - Run Windows apps...
VMware Fusion and Fusion Pro - virtualization software for running Windows, Linux, and other systems on a Mac without rebooting. The latest version includes full support for Windows 10, macOS Mojave... Read more
Apple Configurator 2.10 - Configure and...
Apple Configurator makes it easy to deploy iPad, iPhone, iPod touch, and Apple TV devices in your school or business. Use Apple Configurator to quickly configure large numbers of devices connected to... Read more
Spotify 1.1.15.448. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
MenuMeters 1.9.8 - CPU, memory, disk, an...
MenuMeters is a set of CPU, memory, disk, and network monitoring tools for Mac OS X. Although there are numerous other programs which do the same thing, none had quite the feature set I was looking... Read more

Latest Forum Discussions

See All

Marvel Strike Force is adding Agent Coul...
Marvel Strike Force, the popular squad-based RPG, is set to receive a bunch of new content over the next few weeks. [Read more] | Read more »
Lots of premium games are going free (so...
You may have seen over the past couple weeks a that a bunch of premium games have suddenly become free. This isn’t a mistake, nor is it some last hurrah before Apple Arcade hits, and it’s important to know that these games aren’t actually becoming... | Read more »
Yoozoo Games launches Saint Seiya Awaken...
If you’re into your anime, you’ve probably seen or heard of Saint Seiya. Based on a shonen manga by Masami Kurumada, the series was massively popular in the 1980s – especially in its native Japan. Since then, it’s grown into a franchise of all... | Read more »
Five Nights at Freddy's AR: Special...
Five Nights at Freddy's AR: Special Delivery is a terrifying new nightmare from developer Illumix. Last week, FNAF fans were sent into a frenzy by a short teaser for what we now know to be Special Delivery. Those in the comments were quick to... | Read more »
Rush Rally 3's new live events are...
Last week, Rush Rally 3 got updated with live events, and it’s one of the best things to happen to racing games on mobile. Prior to this update, the game already had multiplayer, but live events are more convenient in the sense that it’s somewhat... | Read more »
Why your free-to-play racer sucks
It’s been this way for a while now, but playing Hot Wheels Infinite Loop really highlights a big issue with free-to-play mobile racing games: They suck. It doesn’t matter if you’re trying going for realism, cart racing, or arcade nonsense, they’re... | Read more »
Steam Link Spotlight - The Banner Saga 3
Steam Link Spotlight is a new feature where we take a look at PC games that play exceptionally well using the Steam Link app. Our last entry talked about Terry Cavanaugh’s incredible Dicey Dungeons. Read about how it’s a great mobile experience... | Read more »
Combo Quest (Games)
Combo Quest 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Combo Quest is an epic, time tap role-playing adventure. In this unique masterpiece, you are a knight on a heroic quest to retrieve... | Read more »
Hero Emblems (Games)
Hero Emblems 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: ** 25% OFF for a limited time to celebrate the release ** ** Note for iPhone 6 user: If it doesn't run fullscreen on your device... | Read more »
Puzzle Blitz (Games)
Puzzle Blitz 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Puzzle Blitz is a frantic puzzle solving race against the clock! Solve as many puzzles as you can, before time runs out! You have... | Read more »

Price Scanner via MacPrices.net

11″ WiFi iPad Pros on sale today for up to $2...
Amazon has new 2018 Apple 11″ WiFi iPad Pros in stock today and on sale for up to $200 off Apple’s MSRP. These are the same iPad Pros sold by Apple in its retail and online stores. Be sure to select... Read more
Select 12″ iPad Pros on sale for $200 off App...
Amazon has select 2018 Apple 12″ iPad Pros in stock today and on sale for $200 off Apple’s MSRP. These are the same iPad Pros sold by Apple in its retail and online stores. Be sure to select Amazon... Read more
Get one of Apple’s new 2019 iPhone 11 models...
Boost Mobile is offering the new 2019 Apple iPhone 11, iPhone 11 Pro, and 11 Pro Max for $100 off MSRP. Their discount reduces the cost of an iPhone 11 to $599 for the 64GB models, $899 for the 64GB... Read more
13″ 1.4GHz Silver MacBook Pros on sale for $1...
B&H Photo has new 2019 13″ 1.4GHz 4-Core Touch Bar Silver MacBook Pros on sale for $100 off Apple’s MSRP. Overnight shipping is free to many addresses in the US. These are the same MacBook Pros... Read more
4-core and 6-core 2018 Mac minis available at...
Apple has Certified Refurbished 2018 Mac minis available on their online store for $120-$170 off the cost of new models. Each mini comes with a new outer case plus a standard Apple one-year warranty... Read more
$250 prepaid Visa card with any Apple iPhone,...
Xfinity Mobile will include a free $250 prepaid Visa card with the purchase of any new iPhone, new line activation, and transfer of phone number to Xfinity Mobile. Offer is valid through October 27,... Read more
Sprint is offering the 64GB Apple iPhone 11 P...
Sprint has the new 64GB iPhone 11 Pro available for $12.50 per month for new customers with an eligible trade-in in of iPhone 7 or newer. That’s down from their standard monthly lease of $41.67. The... Read more
Final week: Apple’s 2019 Back to School Promo...
Purchase a new Mac using Apple’s Education discount, and take up to $400 off MSRP. All teachers, students, and staff of any educational institution with a .edu email address qualify for the discount... Read more
Save $30 on Apple’s AirPods at these reseller...
Amazon is offering discounts on new 2019 Apple AirPods ranging up to $30 off MSRP as part of their Labor Day sale. Shipping is free: – AirPods with Charging Case: $144.95 $15 off MSRP – AirPods with... Read more
Preorder your Apple Watch Series 5 today at A...
Amazon has Apple Watch Series 5 GPS models available for preorder and on sale today for $15 off Apple’s MSRP. Shipping is free and starts on September 20th: – 40mm Apple Watch Series 5 GPS: $384.99 $... Read more

Jobs Board

*Apple* Mobile App Developer - eiWorkflow So...
…eiWorkflow Solutions, LLC is currently looking for a consultant for the following role. Apple Mobile App Developer Tasks the role will be performing: ? Mobile App Read more
Essbase Developer - *Apple* - Theorem, LLC...
Job Summary Apple is seeking an experienced, detail-minded Essbase developer to join our worldwide business development and strategy team. If you are someone who Read more
Student Employment (Blue *Apple* Cafe) Spri...
Student Employment (Blue Apple Cafe) Spring 2019 Penn State University Campus/Location: Penn State Brandywine Campus City: Media, PA Date Announced: 12/20/2018 Date Read more
Best Buy *Apple* Computing Master - Best Bu...
**732093BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Location Number:** 001441-Beaumont-Store **Job Description:** The Read more
*Apple* Mobile Master - Best Buy (United Sta...
**733770BR** **Job Title:** Apple Mobile Master **Job Category:** Store Associates **Location Number:** 000376-Benton Harbor-Store **Job Description:** **What does a Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.