Janvier 2013 - Gambit-list - mailman.iro.umontreal.ca

clang compile time
by Jason Felice 09 Jan '13

09 Jan '13

Does anyone have a solution for the clang compile time issue? I spent an hour in the clang source looking for a way to turn off its crazy-sophisticated tracking of macro expansion, which is my theory about why gambit code takes so long to compile. There's some kind of internal flags for this, but I don't know how to get it through the driver. I was wondering if anyone else has figured this out. -Jason

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Gambit on Samsung Galaxy 4S Relay 4G phone
by Steve Graham 09 Jan '13

09 Jan '13

The interpreter itself seems to work fine. It freezes when I choose the Edit Scripts option and scroll down to the MERS screens. It freezes Gambit, such that none of the buttons work on the screen and the Return and Menu buttons also do not work. Running Advanced Task Killer (free) does not alleviate the problem, only a Restart does that. Steve

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Make the default heap size 1MB
by Bradley Lucier 08 Jan '13

08 Jan '13

Marc: I was looking at the mbrot benchmark with unsafe fixnum and flonum operations; the main loop is Loop 1: (define (count r i step x y) (let ((max-count 64) (radius^2 16.0)) (let ((cr (fl+ r (fl* (exact->inexact x) step))) (ci (fl+ i (fl* (exact->inexact y) step)))) (let loop ((zr cr) (zi ci) (c 0)) (if (fx= c max-count) c (let ((zr^2 (fl* zr zr)) (zi^2 (fl* zi zi))) (if (fl> (fl+ zr^2 zi^2) radius^2) c (let ((new-zr (fl+ (fl- zr^2 zi^2) cr)) (new-zi (fl+ (fl* 2.0 (fl* zr zi)) ci))) (loop new-zr new-zi (fx+ c 1)))))))))) Recomputing floating-point results is often faster than boxing them, so I applied this to zr^2 and zi^2, to get Loop 2: (define (count r i step x y) (let ((max-count 64) (radius^2 16.0)) (let ((cr (fl+ r (fl* (exact->inexact x) step))) (ci (fl+ i (fl* (exact->inexact y) step)))) (let loop ((zr cr) (zi ci) (c 0)) (if (fx= c max-count) c (if (fl> (fl+ (fl* zr zr) (fl* zi zi)) radius^2) c (let ((new-zr (fl+ (fl- (fl* zr zr) (fl* zi zi)) cr)) (new-zi (fl+ (fl* 2.0 (fl* zr zi)) ci))) (loop new-zr new-zi (fx+ c 1))))))))) Results: Default heap: Loop 1: ./mbrot code size = -289 (time (run-bench name count ok? run)) 1792 ms real time 1791 ms cpu time (1770 user, 21 system) 12549 collections accounting for 1499 ms real time (1487 user, 10 system) 2782878336 bytes allocated 44 minor faults no major faults Loop 2: ./mbrot code size = -289 (time (run-bench name count ok? run)) 794 ms real time 793 ms cpu time (785 user, 8 system) 5166 collections accounting for 619 ms real time (614 user, 4 system) 1147411712 bytes allocated 44 minor faults no major faults But increasing the heap from whatever the default is to 1MB (roughly) made an even bigger difference on my machine (2.4GHz Intel Core 2 Duo, Mac OS X 10.6.8): Loop 1: ./mbrot -:m1000 code size = -289 (time (run-bench name count ok? run)) 536 ms real time 535 ms cpu time (530 user, 6 system) 2440 collections accounting for 296 ms real time (293 user, 2 system) 2782736064 bytes allocated 343 minor faults no major faults Loop 2: ./mbrot -:m1000 code size = -289 (time (run-bench name count ok? run)) 289 ms real time 289 ms cpu time (286 user, 3 system) 1000 collections accounting for 121 ms real time (120 user, 1 system) 1147581952 bytes allocated 343 minor faults no major faults Surely 1MB can be OK as a default heap size nowadays ;-)! This is with gsc -v v4.6.6 20120915144211 i386-apple-darwin10.8.0 "./configure 'CC=/pkgs/gcc-4.7.2/bin/gcc -march=core2 -fschedule-insns -frename-registers' '--enable-single-host' '--enable-multiple-versions'" Brad

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Standard Scheme Mode but with Case Sensitivity
by Patrick Li 07 Jan '13

07 Jan '13

Hello, Is it possible to turn on case sensitivity without turning on infix syntax, and keywords in Gambit scheme (i.e. standard scheme mode but with case sensitivity)? I am using the -:s option to enter standard Scheme mode, but I do not know how to turn on case sensitivity after this flag. Thanks very much for your help -Patrick

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Git clone problems
by Bradley Lucier 07 Jan '13

07 Jan '13

I'm getting leibniz-233% git clone https://github.com/feeley/gambit.git Initialized empty Git repository in /tmp/lucier/gambit/.git/ fatal: https://github.com/feeley/gambit.git/info/refs download error - The requested URL returned error: 403 Brad

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What is SSB?
by Bradley Lucier 05 Jan '13

05 Jan '13

Marc: What does this mean? Add support for a SSB which will be used by the generational GC. <https://github.com/feeley/gambit/commit/ad379113ae0ed297043dd2d2a43109ba772…> Brad

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Build gambit as static library
by tcl super dude 03 Jan '13

03 Jan '13

Hi, How can I build gambit as a static library? (build only the static library) I am building an app for android, so I have to use a gambit as a static library to link to my NDK shared library. Everything is working as sujested by https://github.com/seoushi/gambit-android-example , but the compilation fails and I d like a clean method to build the static library without the error on the end of compilation process given while building gsi. thanks for your time

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Alexpander improvements and gambit error locations
by Álvaro Castro-Castilla 03 Jan '13

03 Jan '13

Hi, I've managed to get Alexpander in a quite usable state, I'm happy with it. It's fast and stable, and I managed to make keywords work, so I can use functions defined with ##define in DSSSL extensions, and namespaces for modules (I couldn't do these with psyntax). I also can mix low-level macros, in a second stage, which is good enough, since these are mostly used for very specific stuff related to FFI code generation and compilation helpers. High-level syntax is done in syntax-rules in my code. What I see as a main issue with Alexpander, however, are code locations of errors. Specially, those related to LET and other basic forms which are expanded to fundamental lambdas. That turns the code around all the time making it more difficult to locate the original source of the error. The basic compilation process involves generating intermediate files, expanded with Alexpander and then compiling them with Gambit. I believe that if this is improved (at least avoiding alexpander expansion of let/let*/letrec forms), the resulting syntax system is satisfactory. It could even be made to be compatible with Blackhole's module system, alghouth my alternative allows me the finer control for cross-compilation (Android) that I couldn't achieve in Blackhole after some time hacking it. Any ideas for improving this? I've tried hacking Alexpander removing the redefinitions and making them stubs, but no luck. I'll dive further into Alexpander if I don't find any other solution. What are the consecuences of expanding let/let*/letrec, etc, to lambdas besides code locations? (am I missing any optimizations or some structure used by Gambit for better code generation?) Thanks a lot.

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Multithreading
by Álvaro Castro-Castilla 03 Jan '13

03 Jan '13

Hi! Ok, I know this has been asked before. What are the perspectives of Gambit supporting native threading? I remember that Marc made some tests to see how much the code performance would be affected due to global variables access indirection. However, native threading, at least basic facilities, are a must for programming languagues nowadays. Termite, IPC or network can't be really used for things like games. I think this is a hard problem, of course, and if I would be of any help I'd like to, although I don't have much experience implementing compilers myself. Thanks, Álvaro

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Naming of fixnum bitwise operations
by Bradley Lucier 03 Jan '13

03 Jan '13

Marc: I've been hacking on _num.scm a bit and came across the following naming situation: heine:~/programs/gambit/lib> grep 'fixnum.*bitwise' *gambit*.scm _gambit#.scm:;;; ##fixnum.bitwise-ior ##fixnum.bitwise-xor _gambit#.scm:;;; ##fixnum.bitwise-and ##fixnum.bitwise-not <more stuff omitted> heine:~/programs/gambit/lib> grep 'fxbitwise' *gambit*.scm heine:~/programs/gambit/lib> In making mass changes of ##fixnum.* names to ##fx* names in my codeI found out that ##fxbitwise-ior, etc., are not internal names for procedures. Should these be changed? Brad

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