While porting Tango to D2, I've found the attached file (modified to compile under phobos) doesn't finish compiling in a reasonable amount of time (a.k.a never).
The data table is from the Tango locale package, I stripped out the struct only so there isn't any real tango code, just data.
If I compile the file without -O it compiles in 6 seconds, which seems reasonable since it's 600k of data.
If you comment out most of the lines in the table, it compiles quickly. As you add lines back in, the runtime seems to grow exponentially (not scientifically verified).
This file compiles fine with -O under dmd 1.x, Here's a list of dmd2 compilers that I had on my system to try out:
2.015, 2.016, 2.018: also fails
2.006, 2.007: works
Note that in 2.006 and 2.007, it compiled much quicker with -O (.3 seconds) than without -O using the compilers that fail (6 seconds)
Comment #1 by schveiguy — 2008-10-06T14:31:27Z
Created attachment 275
file to demonstrate bug
Comment #2 by schveiguy — 2008-10-06T16:15:10Z
BTW, this isn't exactly a blocker for Tango/D2, but in order to get it to work, I have to hand-compile the file, as the build-script uses -O for all Tango files.
Comment #3 by bugzilla — 2008-10-07T03:23:10Z
Pulling out part of the loop body as a separate function or nested function should work as a workaround.
Comment #4 by clugdbug — 2011-06-23T03:41:47Z
On DMD2.053 and later, the literal needs to be declared with 'enum' rather than 'static const' to expose the bug.
It's slow because in this case, there is a single expression consisting of 14013 comma expressions, and several places in the backend use algorithms which are in O(commadepth ^^ 2).
One of the slowest is accumrd() in gflow.c.
There is also something slow in loopopt(), boolopt() and in builddags().
Comment #5 by yebblies — 2012-02-01T06:26:21Z
*** Issue 6771 has been marked as a duplicate of this issue. ***
Comment #6 by yebblies — 2012-02-01T06:26:32Z
*** Issue 5684 has been marked as a duplicate of this issue. ***
Comment #7 by yebblies — 2012-02-01T06:26:44Z
*** Issue 6643 has been marked as a duplicate of this issue. ***
Comment #8 by code — 2013-03-12T12:21:56Z
*** Issue 6771 has been marked as a duplicate of this issue. ***