c/8962: "-O2 -mmmx" makes gcc seg fault

[Mack Lobell]

The following reply was made to PR c/8962; it has been noted by GNATS.

From: "Mack Lobell" <macklobell@hotmail.com>
To: bangerth@ticam.utexas.edu
Cc: gcc-bugs@gcc.gnu.org, gcc-gnats@gcc.gnu.org
Subject: Re: c/8962: "-O2 -mmmx" makes gcc seg fault
Date: Sun, 22 Dec 2002 08:55:36 +0000

 Hi,
 
 i removed all functions except the one that makes gcc crash. I have also 
 removed some parts of the code in this function. The file is now ~14000 
 lines of code, where the function is ~3000 lines and the rest are types, 
 forward declarations, etc..
 
 If i try to remove any more code in the function the compiler won't crash. 
 Even if i remove something simple as an assignment the compiler starts to 
 work. I have also noticed that if i remove an unused type (e.g. typedef 
 _fpos_t fpos_t;) the compiler starts to work.
 
 Basically i'm stuck, i can't get it smaller than this. Do you have any 
 "tricks" to reduce the size?
 
 
 Regards.
 
 
 
 
 >From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
 >To: Mack Lobell <macklobell@hotmail.com>
 >CC: gcc-bugs@gcc.gnu.org, <gcc-gnats@gcc.gnu.org>
 >Subject: Re: c/8962: "-O2 -mmmx" makes gcc seg fault
 >Date: Sat, 21 Dec 2002 10:55:13 -0600 (CST)
 >
 >
 > > did the following:
 >
 >Thanks for your experiments. I think there is no need for you to try an
 >even newer snapshot. The only thing you could do is try to strip down the
 >testcase as much as possible, presently it is rather long. We usually do
 >that by first stripping off the line number lines using
 >   perl -pi -e 's/^#.*\n//g;' expr.i
 >so that the compiler gives the _actual_ line number in this file when it
 >crashes. Then try to delete as much stuff from the file as you can.
 >Usually, one can get it down to 20-30 lines and still see the crash. But
 >be warned that this can be a tediuous process that could take 30 minutes
 >to an hour, if you're not frequently doing such things.
 >
 >Thanks for your help
 >   Wolfgang
 >
 >-------------------------------------------------------------------------
 >Wolfgang Bangerth              email:           bangerth@ticam.utexas.edu
 >                                www: http://www.ticam.utexas.edu/~bangerth
 
 
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