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

Gambit versus Python+GMP: Timing for Chudnovskys' algorithm for pi
by Bradley Lucier 08 Avr '22

08 Avr '22

Bakul Shah wrote a particularly elegant Scheme program for Chudnovskys' algorithm for pi based on the Common Lisp program here: https://bitbucket.org/tarballs_are_good/numericl/src/5fe8fe7089f48ab1c8a388… Nick Craig-Wood wrote a Python program using the GMP multiprecision library that appears to use exactly the same algorithm here: http://www.craig-wood.com/nick/articles/pi-chudnovsky/ I modified both programs a bit and include them here. They time the calculation of $10^n$ digits of pi for $n=1,2,3,4,5,6,7$. The results are heine:~/programs/gambiteer/gambit> !py python pi_chudnovsky_bs_gmpy.py 31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679 ('chudnovsky_gmpy_mpz_bs: digits', 10, 'time', 1.0967254638671875e-05) ('chudnovsky_gmpy_mpz_bs: digits', 100, 'time', 3.0040740966796875e-05) Last 5 digits 70679 OK ('chudnovsky_gmpy_mpz_bs: digits', 1000, 'time', 0.00025582313537597656) Last 5 digits 01989 OK ('chudnovsky_gmpy_mpz_bs: digits', 10000, 'time', 0.00386810302734375) Last 5 digits 75678 OK ('chudnovsky_gmpy_mpz_bs: digits', 100000, 'time', 0.0834801197052002) Last 5 digits 24646 OK ('chudnovsky_gmpy_mpz_bs: digits', 1000000, 'time', 1.655979871749878) Last 5 digits 58151 OK ('chudnovsky_gmpy_mpz_bs: digits', 10000000, 'time', 30.67442488670349) Last 5 digits 55897 OK heine:~/programs/gambiteer/gambit> gsi chud1.scm Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10, CPU time: 0.. Last 5 digits 26535. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100, CPU time: 0.. Last 5 digits 70679. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000, CPU time: .004. Last 5 digits 1989. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000, CPU time: .028. Last 5 digits 75678. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000, CPU time: .472. Last 5 digits 24646. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000, CPU time: 6.448. Last 5 digits 58151. Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000000, CPU time: 98.612. Last 5 digits 55897. So it appears that for this algorithm applied to large integers, GMP's bignum routines are about 3-4 times as fast as Gambit's bignum routines. Not so bad. For smaller bignums, GMP has a bigger advantage. The C program gmp-chudnovsky.c includes certain optimizations to this basic algorithm: http://gmplib.org/pi-with-gmp.html ftp://ftp.gmplib.org/pub/misc/gmp-chudnovsky.c On my machine, compiled with gcc -O3 -march=native -o gmp-chudnovsky gmp-chudnovsky.c -lgmp -lm the CPU times for 1,000,000 and 10,000,000 digits are 1.064 and 18.200 seconds, respectively. This is with a somewhat older machine model name : Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz running Ubuntu 13.04 with heine:~/programs/gambiteer/gambit> gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.3-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl --disable-cloog-version-check --disable-ppl-version-check --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) heine:~/programs/gambiteer/gambit> gsi -v v4.6.9 20130607151908 x86_64-unknown-linux-gnu "./configure '--enable-single-host' '--enable-multiple-versions' '--enable-shared'" and the Ubuntu-provided GMP 5.0.5. (I'm sure the GMP folks have a better way to build GMP on my machine than the "generic" 64-bit version provided by Ubuntu.) Brad

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Identifier renaming on load?
by Mikael 18 Déc '13

18 Déc '13

Dear Marc, When (load):ing a binary file ("myfile.o1" etc.) , would there be any way to do identifier renaming at load time? E.g., echo "(define x 5)" >> myfile.scm gsc (compile-file "myfile.scm") (set! ##load-symbol-import (lambda (loaded-symbol-name) 'y)) (load "myfile.o1") y ; => 5 I believe this could be very useful for a module system - not sure though would be happy to understand if there's any problem about it. Without or with modification to Gambit's source. Best regards, Mikael

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What's the best practice for maxing debug settings but having no "console" file output - How get proper debug behavior: ./configure --enable-debug , CFLAGS="-g" ./configure , other?
by Mikael 26 Oct '13

26 Oct '13

Dear Marc, What is the best practice for configuring Gambit to maintain maximum debug settings switched on but no output of a "console" file? ( By maximum debug settings, I mean export of debug symbols, so this could be done by CFLAGS="-g" CXXFLAGS="-g" ./configure , and optionally "-o0" or "-o1" on that - And.. is there any more debug level functionality in Gambit, for instance does --enable-debug switch on any debug functionality beyond -g and "console" file output? The console file is not needed as it's of such a lowlevel nature, and it easily grows infinitely as in >>100GB. Also, switching off while maintaining --enable-debug requires such large amounts of code changes, that I'd presume --enable-debug actually was intended first and foremost as an enabler of "console" file output? ) Thanks! Mikael

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Low prio feature request: GC:able symbols, perhaps via a separate configure option --enable-gc:able-symbols
by Mikael 22 Oct '13

22 Oct '13

Hi! For a lower prio than SMP feature request I wish to suggest GC:able symbols. This would be of use to enable processing of symbols from unsafe or otherwise unknown sources such as frequently is the case in SXML and many other more or less standardized formats. Currently in such use the Gambit process tends to be susceptible to heap overflow possibility/attacks unless there's additional complexity in the form of separate marshalling code that limits symbol import to a pre-specified set only. Very secondarily, an extreme variant of such "unsafe formats" would be some forms of untrusted or otherwise unknown code - for running any form of untrusted code in Gambit, symbols being GC:able would be a key enabler as they'd save the untrusted code handling mechanism of the need to implement symbols<->uninterned symbol conversion in a copying proxy on start and on any passing of values between trusted and untrusted code, and also save of any weird complexity such a proxy would impose on object reference equality, cyclical references support etc. I completely understand that probably the default non-GC:ing quality of symbols is extremely well motivated for minimalism or technical reasons, however wanted to suggest this due to the huge practical use and unifying quality this feature would bring, then as a separate configurable option I guess. If anyone has any thought on this topic feel free to share, Best regards, Mikael

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gsc gets a linker error with -exe
by Dan Wilckens 19 Oct '13

19 Oct '13

Hi, I have a scheme program I'm trying to compile with Gambit-C in MinGW/MSYS under Windows. If I do gsc -exe "filename" the c file is output and gcc compiles fine-until it gets an error in the linker stage:( after successfully compiling DansScheme1.o and DansScheme1_.o and attempting to link them) C:\...lib/libgambc.a(os_base.o):os_base.c:(.text+0x737):undefined reference to 'gai_strerrorA' If I just compile with gsc -c "filename" it puts out a .c file no problem. What should I be looking for? If you need more details let me know. This is version 4.7.0 using Windows Vista with the prebuilt binaries. Any help would be much appreciated.Thanks, Dan

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Patch to speed bignum division in common case
by Bradley Lucier 02 Oct '13

02 Oct '13

Marc: Please find enclosed a patch that speeds bignum division in the common case where (quotient a b) is a relatively small integer. Please apply this patch even though it's not a git fetch request. It's been going around in my head for a long time now, and I'd like to get rid of it before I learn about git. In pidigit.scm, a spigot algorithm for calculating the digits of pi, all (or almost all, I haven't checked) of the quotients return a single decimal digit. So this new code improves this performance of this benchmark a bit: To calculate 10,000 decimal digits of pi: Before the patch: firefly:~/programs/gambit/4.6.8/gambit> time ./pidigits2-gambit > /dev/null 5.560u 0.052s 0:05.63 99.6% 0+0k 0+0io 0pf+0w firefly:~/programs/gambit/4.6.8/gambit> time ./pidigits2-gambit > /dev/null 5.564u 0.044s 0:05.62 99.6% 0+0k 0+0io 0pf+0w firefly:~/programs/gambit/4.6.8/gambit> time ./pidigits2-gambit > /dev/null 5.588u 0.048s 0:05.65 99.4% 0+0k 0+0io 0pf+0w After the patch: firefly:~/programs/gambit/4.6.8/gambit> time ./pidigits2-gambit > /dev/null 4.684u 0.024s 0:04.72 99.5% 0+0k 0+0io 0pf+0w firefly:~/programs/gambit/4.6.8/gambit> time ./pidigits2-gambit > /dev/null 4.676u 0.040s 0:04.73 99.5% 0+0k 0+0io 0pf+0w firefly:~/programs/gambit/4.6.8/gambit> time ./pidigits2-gambit > /dev/null 4.648u 0.032s 0:04.69 99.5% 0+0k 0+0io 0pf+0w The code may also improve the performance of (very) bignum gcd, but I haven't checked that. Thoroughly "white box" and "black box" tested. The code includes better bignum shift code that I plan to use later in other places. Brad

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xkcd: Functional
by Bradley Lucier 01 Oct '13

01 Oct '13

http://xkcd.com/1270/ Brad

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Returning values from ##inline-host-code
by Alexander Shendi 01 Oct '13

01 Oct '13

Dear list, how do I return values from a "##inline-host-code" form? Here is my attempt, but it doesn't seem to work ... (define (command-line) (vector->list (##inline-host-code "var vect = new Gambit_vector(); for(i=0; i < process.argv.length; i++) { vect.a[i] = process.argv[i]; } Gambit_r1 = vect; "))) Many thanks in advance, Alexander

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Build sample for android on linux failed
by 陈进芬 30 Sep '13

30 Sep '13

I've just tried to build the Calculator sample app coming from LambdaNative for android on linux,but I got two problems 1.WARNINGS *** WARNING -- "calc_14.fnt" is not defined, *** referenced in: ("/home/chenjf/apps/lambdanative/lambdanative-master-cache/android/build/3c4d196ded4c65584af892a98a926ace.c") *** WARNING -- "calc_24.fnt" is not defined, *** referenced in: ("/home/chenjf/apps/lambdanative/lambdanative-master-cache/android/build/3c4d196ded4c65584af892a98a926ace.c") *** WARNING -- "calc_32.fnt" is not defined, *** referenced in: ("/home/chenjf/apps/lambd 2.Error./make.sh: line 334: /home/chenjf/apps/lambdanative/lambdanative-master/tmp.bJKtPg/src/ hughjfchen.com/hughjfchen/calculator/Calculator.java: No such file or directory ERROR: failed with exit code 1 >> substitution failed on bootstraps/android/bootstrap.java.in For the error,I checked the generated code and found /home/chenjf/apps/lambdanative/lambdanative-master/tmp.bJKtPg/src/hughjfchen/com/hughjfchen/calculator/Calculator.java So looks like that the generated dir should be hughjfchen/com, not the hughjfchen.com Is that a problem of Lambdanative or android-sdk? And following are my dev enviroment: lambdanative master branch source code from GIT android sdk 22.2.1 android sdk platform tool 18.0.1 android sdk build tool 18.0.1 android 2.3.3 (API 10) archlinux linux with kernel 3.11.2 -- Thanks and best regards, Hugh Chen ------------------------------------- Email: hugh.jf.chen(a)gmail.com "Work smart;Not work hard!"

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Build sample for android on linux failed
by 陈进芬 30 Sep '13

30 Sep '13

I've just tried to build the Calculator sample app coming from LambdaNative for android on linux,but I got two problems 1.WARNINGS *** WARNING -- "calc_14.fnt" is not defined, *** referenced in: ("/home/chenjf/apps/lambdanative/lambdanative-master-cache/android/build/3c4d196ded4c65584af892a98a926ace.c") *** WARNING -- "calc_24.fnt" is not defined, *** referenced in: ("/home/chenjf/apps/lambdanative/lambdanative-master-cache/android/build/3c4d196ded4c65584af892a98a926ace.c") *** WARNING -- "calc_32.fnt" is not defined, *** referenced in: ("/home/chenjf/apps/lambd 2.Error./make.sh: line 334: /home/chenjf/apps/lambdanative/lambdanative-master/tmp.bJKtPg/src/ hughjfchen.com/hughjfchen/calculator/Calculator.java: No such file or directory ERROR: failed with exit code 1 >> substitution failed on bootstraps/android/bootstrap.java.in For the error,I checked the generated code and found /home/chenjf/apps/lambdanative/lambdanative-master/tmp.bJKtPg/src/hughjfchen/com/hughjfchen/calculator/Calculator.java So looks like that the generated dir should be hughjfchen/com, not the hughjfchen.com Is that a problem of Lambdanative or android-sdk? And following are my dev enviroment: lambdanative master branch source code from GIT android sdk 22.2.1 android sdk platform tool 18.0.1 android sdk build tool 18.0.1 android 2.3.3 (API 10) archlinux linux with kernel 3.11.2 -- Thanks and best regards, Hugh Chen ------------------------------------- Email: hugh.jf.chen(a)gmail.com "Work smart;Not work hard!"

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