MinGW and -fomit-frame-pointer problem cleared up

[Mike Pall <mikelu-0602@...>]

Hi,

it has been mentiond on the list a few times that there are
mysterious failures with MinGW/Cygwin when compiling with
-fomit-frame-pointer.

I've tracked this down and found a corresponding bug report:
  http://www.cygwin.com/ml/cygwin/2004-11/msg00962.html

It's basically a wrong generation of unwind info for stdcalls,
but only when the outgoing args are not accumulated. This happens
only under some, but not all optimization and CPU type settings.

The fix is available starting with GCC 4.0. It has not been
backported to GCC 3.x.

A suggested workaround for GCC 3.x is to always use two flags:
  -fomit-frame-pointer -maccumulate-outgoing-args

Hope this saves someone else a few days of bug hunting ...

Bye,
     Mike