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digitalmars.D.bugs - [Issue 7964] New: Organic Bug

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=7964

           Summary: Organic Bug
           Product: D
           Version: D2
          Platform: x86_64
        OS/Version: Linux
            Status: NEW
          Severity: critical
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: iteronvexor gmail.com


--- Comment #0 from Caligo <iteronvexor gmail.com> 2012-04-21 22:24:53 PDT ---
Location: Earth
Temperature: 64F
Wind: SE at 5 mph            
Humidity: 45%

DMD 2.059, 64-bit GNU/Linux
----------------------------------->8----------------------------------->8-----------------------------------
import std.typecons  : Tuple;
import std.array     : appender;
import std.algorithm : sort;
import std.stdio     : writeln;


alias double Real;

struct S {
  Tuple!(Real, Real)[] _data;
  alias _data this;
}

private auto gen(K, V)(V[K] data) {
  alias Tuple!(K, V) T;
  T[] app;
  foreach(k, v; data)
    app ~= T(k,v);
  sort(app);
  return app;
}

auto s(Real[Real] data) {
  return S(gen!(Real, Real)(data));
}

S bug = 
  s([360.0:0.000000122200, 361.0:0.000000185138, 362.0:0.000000278830,
363.0:0.000000417470,
     364.0:0.000000621330, 365.0:0.000000919270, 366.0:0.000001351980,
367.0:0.000001976540,
     368.0:0.000002872500, 369.0:0.000004149500, 370.0:0.000005958600,
371.0:0.000008505600,
     372.0:0.000012068600, 373.0:0.000017022600, 374.0:0.000023868000,
375.0:0.000033266000,
     376.0:0.000046087000, 377.0:0.000063472000, 378.0:0.000086892000,
379.0:0.000118246000,
     380.0:0.000159952000, 381.0:0.000215080000, 382.0:0.000287490000,
383.0:0.000381990000,
     384.0:0.000504550000, 385.0:0.00066244]);

void main() { }
-----------------------------------8<-----------------------------------8<-----------------------------------

compiling the above gives:

/usr/include/x86_64-linux-gnu/dmd/phobos/std/algorithm.d(1498): Error:
reinterpreting cast from Tuple!(double,double)* to ubyte* is not supported in
CTFE
/usr/include/x86_64-linux-gnu/dmd/phobos/std/algorithm.d(7018):        called
from here: swap(r[i1],r[i2])
/usr/include/x86_64-linux-gnu/dmd/phobos/std/algorithm.d(7047):        called
from here: swapAt(r,pivotIdx,r.length - 1LU)
/usr/include/x86_64-linux-gnu/dmd/phobos/std/algorithm.d(6787):        called
from here: sortImpl(r)
t1.d(19):        called from here: sort(app)
t1.d(24):        called from here: gen(data)
t1.d(28):        called from here:
s([360:1.222e-07,361:1.85138e-07,362:0x9.5b21a78330de599p-25,363:0xe.020a3d0e070d933p-25,364:0xa.6c978f4795f4a92p-24,365:9.1927e-07,366:1.35198e-06,367:1.97654e-06,368:2.8725e-06,369:0x8.b3beeffb8c391a1p-21,370:0xc.7effbf874cb77f1p-21,371:8.5056e-06,372:0xc.a7a3e07ee23183ap-20,373:1.70226e-05,374:2.3868e-05,375:3.3266e-05,376:4.6087e-05,377:6.3472e-05,378:8.6892e-05,379:0xf.7fad67e041a747ep-17,380:0.000159952,381:0.00021508,382:0.00028749,383:0xc.845d4758da0bcfap-15,384:0x8.443c6ff2d722913p-14,385:0.00066244])


Shortening the associative array by just one works.  That is to say:

...
S bug = 
  s([360.0:0.000000122200, 361.0:0.000000185138, 362.0:0.000000278830,
363.0:0.000000417470,
     364.0:0.000000621330, 365.0:0.000000919270, 366.0:0.000001351980,
367.0:0.000001976540,
     368.0:0.000002872500, 369.0:0.000004149500, 370.0:0.000005958600,
371.0:0.000008505600,
     372.0:0.000012068600, 373.0:0.000017022600, 374.0:0.000023868000,
375.0:0.000033266000,
     376.0:0.000046087000, 377.0:0.000063472000, 378.0:0.000086892000,
379.0:0.000118246000,
     380.0:0.000159952000, 381.0:0.000215080000, 382.0:0.000287490000,
383.0:0.000381990000,
     384.0:0.000504550000]);
...

does not trigger the bug.  Also, commenting out 'sort(app)' does not trigger
the bug.  This is as organic as it gets.

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next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=7964


Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |clugdbug yahoo.com.au


--- Comment #1 from Don <clugdbug yahoo.com.au> 2012-04-23 22:18:06 PDT ---
I don't know what you mean by "organic". The code works for arrays which are
small enough that sort() uses insertion sort, but when sort() switches to
quicksort, it does an unsafe cast that CTFE doesn't support.

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|DMD                         |Phobos
           Platform|x86_64                      |All
            Summary|Organic Bug                 |std.algorithm.swap is not
                   |                            |CTFE-compatible for structs
                   |                            |with non-trivial assignment
         OS/Version|Linux                       |All
           Severity|critical                    |normal


--- Comment #2 from Don <clugdbug yahoo.com.au> 2012-05-21 00:49:58 PDT ---
Changing to a Phobos bug because the error message is perfectly clear; there's
no compiler bug here, and nothing strange going on. Priority reduced from
critical to normal.

CTFE is complaining because std.algorithm.swap is doing a nasty hack. I'm not
sure if the hack is really valid for structs with postblit.

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prev sibling parent d-bugmail puremagic.com writes:
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timon.gehr gmx.ch changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |timon.gehr gmx.ch


--- Comment #3 from timon.gehr gmx.ch 2012-05-21 02:52:54 PDT ---
(In reply to comment #2)
 Changing to a Phobos bug because the error message is perfectly clear; there's
 no compiler bug here, and nothing strange going on. Priority reduced from
 critical to normal.
 
 CTFE is complaining because std.algorithm.swap is doing a nasty hack. I'm not
 sure if the hack is really valid for structs with postblit.
Postblit has to be called when a struct is copied, but not when it is moved. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
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