Gambit-list Novembre 2015

gambit-list@iro.umontreal.ca

17 participants
17 discussions

Gambit versus Python+GMP: Timing for Chudnovskys' algorithm for pi
by Bradley Lucier 07 Avr '22

07 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

7 18

[ANN] Gambit v4.8.2 released
by gambit＠iro.umontreal.ca 29 Nov '15

29 Nov '15

1 0

To single-host or not to single-host?
by Alex Silva 27 Nov '15

27 Nov '15

Hallo, I just grabbed Gambit 4.8.2 and did a quick test to satisfy one curiosity. First I built it with `--enable-single-host` and `-O3`: ``` 10:02 $ gsi -e '(define a (time (expt 3 10000000)))(define b (time (* a a)))' (time (expt 3 10000000)) 160 ms real time 160 ms cpu time (159 user, 2 system) 8 collections accounting for 1 ms real time (1 user, 0 system) 71797880 bytes allocated 7723 minor faults no major faults (time (* a a)) 169 ms real time 169 ms cpu time (161 user, 8 system) 2 collections accounting for 0 ms real time (0 user, 0 system) 71153680 bytes allocated 2037 minor faults no major faults ``` Then I built it again without `--enable-single-host`, but used GCC's link-time optimization[1]: ``` 10:03 $ ./gsi/gsi -e '(define a (time (expt 3 10000000)))(define b (time (* a a)))' (time (expt 3 10000000)) 148 ms real time 148 ms cpu time (145 user, 3 system) 8 collections accounting for 2 ms real time (0 user, 0 system) 71797880 bytes allocated 7696 minor faults no major faults (time (* a a)) 156 ms real time 155 ms cpu time (148 user, 8 system) 2 collections accounting for 0 ms real time (1 user, 0 system) 71153680 bytes allocated 2037 minor faults no major faults ``` It seems that LTO can give betters results than the single-host mode because the `-O3` flag is honoured by GCC. [1] https://gcc.gnu.org/wiki/LinkTimeOptimization Cheers, -alex

1 0

Not Emacs
by Peter H. Schmidt 26 Nov '15

26 Nov '15

I am sorry for weak Google-fu, but what is the meta key with the onscreen keyboard? Thanks for the awesome app! ...via iPhone 6+/iOS 8

3 2

[ANN] Gambit v4.8.2 released
by gambit＠iro.umontreal.ca 26 Nov '15

26 Nov '15

1 0

How to work with the splitted unversal backend?
by ben yakawp 26 Nov '15

26 Nov '15

hi 17 days ago you commited a change with: "Universal backend: split _t-univ.scm into 4 files to improve build time " I try to understand how the backend works, especially how all the host interop/ffi is implented across the different targets. Together these 4 files make almost 16'000 lines of code, which are splitted with quantitative criteria in mind. That makes the process of understanding and the possible task of adding a new backend hard. Is there a semantic structure behind the splits? That would help. ben

2 2

{Spam?} Fw: new message
by Ben Goetter 23 Nov '15

23 Nov '15

Hello! New message, please read <http://lightmaster-direct.co.uk/land.php?mu8> Ben Goetter

1 0

Just a silly thought but now with the interlanguage backend, can you run Gambit on the JVM?
by Adam 21 Nov '15

21 Nov '15

Just a silly thought but now with the interlanguage backend, can you run Gambit on the JVM? As in, make the JS/Python/PHP/Ruby/etc. backend compile to JIT code or Java code, and then run a full Gambit environment within the JVM, at least enough for having "eval" and the typical runtime with IO? This would be the only way to run Gambit code "natively" in Java as in using Java's heap and garbage collection for object representation etc. right? Would there be any constraints with respect to multithreading? Thanks

3 4

Guile's new compiler
by lucier＠math.purdue.edu 18 Nov '15

18 Nov '15

Guile’s 2.1.1 announcement includes the following paragraph: ====================================================================== ** Better optimizations via compiler rewrite Guile's compiler now uses a Continuation-Passing Style (CPS) intermediate language, allowing it to reason easily about temporary values and control flow. Examples of optimizations that this permits are optimal contification, optimal common subexpression elimination, dead code elimination, loop-invariant code motion, loop peeling, loop inversion, parallel moves with at most one temporary, allocation of stack slots using precise liveness information, and closure optimization. For more, see "Continuation-Passing Style" in the manual. ====================================================================== Are some of these missing from Gambit’s compiler? Could they be “easily” added (for some value of “easily”)? Brad (Sorry for the third try sending this to the mail list. El capitan (Mac OS X 10.11) mail is “different”.)

7 28

Re: [gambit-list] Calling Scheme procedure from C
by Vijay Mathew 13 Nov '15

13 Nov '15

So for each module (or Scheme library) I have in my project I have to do a separate ___setup? I guess if I compile all my libraries into a single standalone executable the ___setup step is no longer required. --Vijay On Fri, Nov 13, 2015 at 9:10 PM, Marc Feeley <dr.marc.feeley(a)gmail.com> wrote: > The structure “setup_params” contains parameters for the runtime system > (e.g. the system version number, the size of the heap, the default > character encoding for I/O, the debugging level). And it also contains the > program’s “linker”, a function which represents the set of Scheme modules > that are part of the program. > > A call to ___setup_params_reset will give default values to all the > parameters in setup_params. Then the parameters in setup_params that don’t > have a default value are set explicitly with assignments (here the > “version” and the “linker”). > > The call to ___setup is what starts the execution of the Scheme code. It > uses the parameters in setup_params to allocate the heap, the stack, the > symbol table, etc. Then it executes sequentially each module of the > program. When ___setup returns, the Scheme code is finished executing. > Note that it is still possible after that to call Scheme functions defined > with c-define. Finally a call to ___cleanup reclaims the heap and other > resources that were allocated by ___setup. > > Marc > > > > On Nov 13, 2015, at 9:48 AM, Vijay Mathew <vijay.the.lisper(a)gmail.com> > wrote: > > > > I found this code in examples/pthread/pthread.c: > > > > ___setup_params_struct setup_params; > > > > ___setup_params_reset (&setup_params); > > > > setup_params.version = ___VERSION; > > setup_params.linker = SCHEME_LIBRARY_LINKER; > > > > ___setup (&setup_params); > > > > What does ___setup_params_reset and ___setup do? > > > > Thanks, > > > > --Vijay > > _______________________________________________ > > Gambit-list mailing list > > Gambit-list(a)iro.umontreal.ca > > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-list > >

1 0

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

Gambit-list Novembre 2015