Octobre 2006 - Gambit-list - mailman.iro.umontreal.ca

Re: [gambit-list] gcc stage timing
by Marc Feeley 17 Oct '06

17 Oct '06

On 14-Oct-06, at 9:59 PM, Bradley Lucier wrote: > > On Oct 4, 2006, at 12:07 PM, Marc Feeley wrote: > >> P.P.S. I wrote a genetic algorithm to figure out which >> combination of options gives the best results. Its pretty cool! >> Here's the code: > > Marc: > > Yes, this is cool. I'm wondering, can you write this as a > distributed app that I can run on my 12 opteron cores over two > systems? Most of the time nothing else is running (well, except > for Folding@Home), so it would be cool to run something like this. > Also, I see you used a population of 25 in the code you sent; when > I was doing genetic programming (where you evolve programs) for > image processing, I used a population of at least 2,000. So I'd > like to try it with a larger population, too. > > Brad Here's the program. You have to run it in the "bench" subdirectory. If you want to parallelize it, you will have to change the procedure "evaluate-group" so that it performs a "parallel map": (define (evaluate-group pop) (map evaluate-individual pop)) You also have to change the "evaluate" script (in the "bench" subdirectory) so that it doesn't clobber files that are generated by the concurrent invocations of the "evaluate" script. Finally, don't forget to modify the bin/gsc-cc-o script in the installation directory so that only a minimal set of GCC options are used (otherwise the options that the optimization program thinks it is using and the actual ones used by GCC will be different). Marc

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res_query in the FFI
by Lang Martin 14 Oct '06

14 Oct '06

I'm trying to make a largish number of DNS MX type queries, thread-safely. I made a djbdns FFI, that works great. It's not thread safe -- the library internally uses global state variables. So. Started working on res_query, which seems like it's probably thread safe. However, res_query returns it's answer as a buffer of some size of u_char's. What do I do with those? There's the type conversion thing in the manual for ECDIC characters which is incomplete, and it seems as though the unicode support in Gambit is implemented through byte ports. Should I create a port? If so, can someone point me to a bit of the source code that'll get me started with that? Should I convert the answer string to some other format? I'd like to preserve any unicode characters that return from DNS. Should I return a byte vector from the function and run some scheme-land conversion on it to create a string? that'd be nice, I'm not really a C programmer. If someone can light my way, I'd appreciate it. Lang

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Re: [gambit-list] strange mutation problem (bug?) (Re: "Number of arguments exceeds implementation)
by Christian 13 Oct '06

13 Oct '06

At 21:04 Uhr -0500 02.10.2006, Bill Richter wrote: >Excellent, Marc! I suppose I made a contribution to Gambit, through >tenacity if not Scheme sense. Next time, try to prove your tenacity by tracking down the problem yourself, please :) >I didn't even know that #( meant a >constant. All literal values are (or can be considered) constants. Christian.

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inlining eqv? etc.
by Bradley Lucier 13 Oct '06

13 Oct '06

Marc: I'm going over c#prim-procs to see which other routines could be inlined. First, I'm comparing (##define-macro (macro-number-dispatch num err fix big rat flo cpx) `(cond ((##fixnum? ,num) ,fix) ((##flonum? ,num) ,flo) ((##subtyped? ,num) (let ((##s (##subtype ,num))) (cond ((##fixnum.= ##s (macro-subtype-bignum)) ,big) ((##fixnum.= ##s (macro-subtype-ratnum)) ,rat) ((##fixnum.= ##s (macro-subtype-cpxnum)) ,cpx) (else ,err)))) (else ,err))) in _num#.scm with (define-prim (##flonum? obj) (and (##subtyped? obj) (##eq? (##subtype obj) (macro-subtype-flonum)))) in sys.scm, and I suggest macro-number-dispatch be redefined as (##define-macro (macro-number-dispatch num err fix big rat flo cpx) `(cond ((##fixnum? ,num) ,fix) ((##subtyped? ,num) (let ((##s (##subtype ,num))) (cond ((##fixnum.= ##s (macro-subtype-flonum)) ,flo) ((##fixnum.= ##s (macro-subtype-bignum)) ,big) ((##fixnum.= ##s (macro-subtype-ratnum)) ,rat) ((##fixnum.= ##s (macro-subtype-cpxnum)) ,cpx) (else ,err)))) (else ,err))) Now, I look at (define-prim (##eqv? obj1 obj2) (macro-number-dispatch obj1 (##eq? obj1 obj2) (and (##fixnum? obj2) (##fixnum.= obj1 obj2)) ; obj1 = fixnum (and (##bignum? obj2) (##bignum.= obj1 obj2)) ; obj1 = bignum (and (##ratnum? obj2) (##ratnum.= obj1 obj2)) ; obj1 = ratnum (and (##flonum? obj2) (##bvector-equal? obj1 obj2)) ; obj1 = flonum (and (##cpxnum? obj2) ; obj1 = cpxnum (##eqv? (macro-cpxnum-real obj1) (macro-cpxnum-real obj2)) (##eqv? (macro-cpxnum-imag obj1) (macro-cpxnum-imag obj2))))) in sys.scm. I think one can (should?) inline (##eqv? x y) as (or (##eq? x y) (and (##subtyped? x) (##subtyped? y) (let ((##sx (##subtype x))) (and (##fixnum.= ##sx (##subtype y)) (or (##fixnum.= ##sx (macro-subtype-flonum)) (##fixnum.= ##sx (macro-subtype-bignum)) (##fixnum.= ##sx (macro-subtype-ratnum)) (##fixnum.= ##sx (macro-subtype-cpxnum))) (##eqv? x y))))) The second limb of the first "or" can be be eliminated for many compile-time constants (please use the commutativity of ##eqv? if y happens to be a compile-time constant and x isn't), which can be especially important for compiling "case" forms. There are a number of "case" forms in the files compiler, dynamic, early, graphs, lattice, matrix, nboyer, nucleic, sboyer, scheme, and test in bench/src. In your latest benchmarks Bigloo beat Gambit in boyer, dynamic, and scheme; maybe the lack of inlining of eqv? in case contributed. Perhaps one can use a similar strategy for inlining equal? Other things that could (should?) be inlined (perhaps some of these already are inlined for special values of the arguments): boolean? list-ref (like memv) memv (now that eqv? can be inlined) assv (ditto) number?, complex?, real?, rational?, integer?, exact?, inexact? (it doesn't seem so bad to inline macro-number-dispatch since the results are boolean, or at least these could be tested for fixnum and flonum) abs (for fixnum, using ##fixnum.-? if the argument is negative) gcd and lcm (for one argument) numerator and denominator (for fixnums) floor, ceiling, truncate, round (for fixnums) real-part, imag-part, magnitude (for fixnum and flonum arguments) string string=? and friends with 0 and 1 arguments. Generally, I went through all the items in prim-procs, and generated little programs that used them with varying number of arguments, then visually inspected the expanded code and (sometimes) the C code to see what's going on. I'm including my little test file at the end. Brad

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SSAX
by Aycan iRiCAN 10 Oct '06

10 Oct '06

Hi, Is it possible to use SSAX with gambit? Anyone using it? After running "make SSAX-code.scm" I tried to load it: > (load "~/scheme/SSAX/lib/SSAX.scm") *** ERROR IN "../../../SSAX/lib/SSAX.scm"@307.16 -- Ill-placed 'define' Note: SSAX cvs. Best Regards, -- Aycan iRiCAN C0R3 Computer Security Group http://people.core.gen.tr/~aycan.irican/

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equal greater symbol
by Aycan iRiCAN 09 Oct '06

09 Oct '06

Hi, What is the meaning of '=> symbol used in cond forms? Best Regards, -- Aycan iRiCAN C0R3 Computer Security Group http://people.core.gen.tr/~aycan.irican/

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example web server
by Aycan iRiCAN 08 Oct '06

08 Oct '06

Hi, I start the web-server example with the command: gsi html http web-server 8000 after that, web continuation example gives error: The following Scheme exception occurred while processing the request: Unbound variable: base64#u8vector->base64-string I think it should be started with a command like this: gsi base64 html http web-server 8000 The README file in web-server example needs to be updated. Best Regards, -- Aycan iRiCAN C0R3 Computer Security Group http://people.core.gen.tr/~aycan.irican/

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Gambit-C 4.0 beta 20
by Marc Feeley 07 Oct '06

07 Oct '06

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Gambit-C 4.0 beta 20 is now available. The source tarball is here: <http://www.iro.umontreal.ca/~gambit/download/gambit/4.0/source/ gambc-4.0b20.tar.gz> A prebuilt installation for Microsoft Windows is available here: <http://www.iro.umontreal.ca/~gambit/download/gambit/4.0/prebuilt/ gambc-4.0b20-win.zip> Just unzip it in C: to get C:\Gambit-C\4.0b20, then add C:\Gambit-C\4.0b20\bin to your path. Here are the highlights of this release: - The mutation procedures (set-car!, set-cdr!, vector-set!, string-set!, etc) now check that the object is mutable (not a constant). For example: Gambit Version 4.0 beta 20 > (define x (symbol->string 'hello)) > (string-set! x 0 #\m) *** ERROR IN (console)(a)2.1 -- (Argument 1) MUTABLE object expected (string-set! "hello" 0 #\m) - The compiler, gsc, now produces dynamically loadable object files by default. The -dynamic flag is thus optional. To generate a link file (which used to be the default) you must use the -link option. - The GCC compilation options used for Gambit have been updated to improve the code generation (execution time is 5% to 30% faster than before). The set of compilation options was obtained by a genetic algorithm. - The --enable-gcc-opts configure option has been added. It enables some expensive GCC optimizations (the build time more than doubles and you need lots of RAM, i.e. 2 gigabytes or more). - Minor bug fix in the reader which treated #\ 123 as a syntax error instead of #\space followed by 123. - The runtime source code (in C) has been reorganized to be able to build Gambit on systems that are neither POSIX or WIN32. In this case the Gambit runtime will not include functionality such as networking, processes, and preemptive multithreading. It will use (blocking) stdio to do all I/O (presumably nearly all platforms, even embedded systems, have some library for stdio even if it is just a minimal functionality such as directing stdin/stdout to a serial port). Marc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (Darwin) iD8DBQFFJm2y//V9Zc2T/v4RAkuTAJ0Vctr2zwPHys7QEnEo2tNG5yqB4QCeNNQI 2/pVeYwzS8vnLnOwy1/Dgec= =xK9g -----END PGP SIGNATURE-----

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Question from Newbie
by Sen, Suchira 05 Oct '06

05 Oct '06

Hi, I am new to gambit and am trying to write a journal file. I need to create an array to store strings, When I use the foll: declare $cve[1:3], and try to enter a string variable Ex. $cve[1]="vertex." - I find that the array cve is marked as an array of 'unknown type'. And the variables stored in it are also marked similarly. But if I sya $cve[1]=1, then it happily assigns a numeric value to it. So my question is how do we declare an array to be a character type? Thanks, Suchira.

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Re: [gambit-list] strange mutation problem (bug?) (Re: "Number of arguments exceeds implementation)
by Christian 03 Oct '06

03 Oct '06

At 1:17 Uhr -0500 29.09.2006, Bill Richter wrote: >Christian suggested I might have found a real bug, The interesting bit is, that using compile-file & load Bill's program usually works, whereas with static compilation/linking not. I don't know where Gambit would differ in those two >and that I should >try stripping off as much fat as possible from my program. You should strip it more until you can say "if I leave this out, it doesn't do weird things anymore". Here's what you should be doing in such cases: * check which functions are really mutating, and which ones are functions. I realize that you're using map (meant for functions) where I think for-each (meant for imperative code) is what you want (maybe the order of evaluation may be a problem!). I realize that UnSpace clearly does mutate it's argument, thus rename it to UnSpace!. * try to find out whether ShowPossibilities mutates it's argument. From a quick look at the code, I'd say so, but runnning it in gsi, I couldn't find a modification of it's input, strange. * try to find out where during the runtime of the program the problem happens. For this, outputting the relevant datastructures helps. I've put a (pp U7) between the two ShowPossibilities calls and another one after the second. After the first ShowPossibilities call U7 is containing lists (is this what you want?); then the second ShowPossibilities call runs into the error. So clearly U7 has been modified, and ShowPossibilities should be renamed to ShowPossibilities!. Why does the same not happen in the interpreter? Before knowing that it's a Gambit bug, we have to rule out that it's from a difference between interpreter and compiler behaviour. Trimming it further down for an hour, I realize that you're modifying quoted datastructures. IIRC, R5RS says that modifying constant datastructures is undefined, and Gambit seems to rely on them not beeing modifyed when compiling to static binaries. Replace all quoted #(..) with (vector ..) and it works. Christian.

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