Everyone working on the C side might want to read this article...

[Rob Browning]

The following article explains gcc changes that may be behind at least
some of our recent set of bugs:

  http://www.ddj.com/documents/s=880/ddj0010d/0010d.htm

You may not need to read it if you're already familiar with what the C
standard says about type aliasing, or already know that (for example)
according to the standard this code is illegal and the results are
undefined:

   double d = 3.0;
   int* ip = (int*) &d;
   *ip = 7;

or if you know that an optimizer is within its rights according to the
standard to translate this:code:

  double d = 2.0;
  int *ip = (int*) &d;
  *ip = 3;
  d *= 2;

into this code:

  double d = 2.0;
  int *ip = (int*) &d;
  d *= 2;
  *ip = 3;

Thanks to Marius for tracking the pointer down.  I'm not yet sure what
this means for our code.

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
GPG starting 2002-11-03 = 14DD 432F AE39 534D B592  F9A0 25C8 D377 8C7E 73A4