Parallel example from documentation does not compile
Russel Winder via Digitalmars-d-learn
digitalmars-d-learn at puremagic.com
Fri Feb 19 20:23:56 PST 2016
Sadly the answer is no.
This is due to https://issues.dlang.org/show_bug.cgi?id=5710 which
apparently no-one is either willing or able to fix. The problem
afflicts dmd, l;dc2 and I suspect gdc.
cf. https://github.com/russel/Pi_Quadrature/tree/master/D
for some extra detail and some workarounds.
It appears I had not added this original version, but I am now fixing
this.
On Fri, 2016-02-19 at 21:57 +0000, Ish via Digitalmars-d-learn wrote:
> This code snippet is from:
> http://dlang.org/phobos/std_parallelism.html
> ---
> import std.algorithm, std.parallelism, std.range;
>
> void main() {
> // Parallel reduce can be combined with
> // std.algorithm.map to interesting effect.
> // The following example (thanks to Russel Winder)
> // calculates pi by quadrature using
> // std.algorithm.map and TaskPool.reduce.
> // getTerm is evaluated in parallel as needed by
> // TaskPool.reduce.
> //
> // Timings on an Athlon 64 X2 dual core machine:
> //
> // TaskPool.reduce: 12.170 s
> // std.algorithm.reduce: 24.065 s
>
> immutable n = 1_000_000_000;
> immutable delta = 1.0 / n;
>
> real getTerm(int i)
> {
> immutable x = ( i - 0.5 ) * delta;
> return delta / ( 1.0 + x * x ) ;
> }
>
> immutable pi = 4.0 * taskPool.reduce!"a + b"(
> std.algorithm.map!getTerm(iota(n))
> );
> }
>
> dmd compiler gives error:
> /usr/include/dmd/phobos/std/parallelism.d(2624): Error: function
> std.parallelism.TaskPool.reduce!"a +
> b".reduce!(MapResult!(getTerm, Result)).reduce cannot get frame
> pointer to D main
>
> Is there way to compile it?
>
> -Ish
--
Russel.
=============================================================================
Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.winder at ekiga.net
41 Buckmaster Road m: +44 7770 465 077 xmpp: russel at winder.org.uk
London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: This is a digitally signed message part
URL: <http://lists.puremagic.com/pipermail/digitalmars-d-learn/attachments/20160220/311e8eb4/attachment.sig>
More information about the Digitalmars-d-learn
mailing list