optimization/2927: gcc build of xemacs 21.1.14 core dumps with -O3 but not with -O2

[pdl at la dot utexas dot edu]

>Number:         2927
>Category:       optimization
>Synopsis:       gcc build of xemacs 21.1.14 core dumps with -O3 but not with -O2
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Thu May 24 10:36:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     pdl@la.utexas.edu
>Release:        gcc snapshot for 14-May-2001
>Organization:
>Environment:
Solaris 2.6, X Windows 11 R6.3, GNU ld, Ultra Sparc 2-300
>Description:
The default build configuration for Xemacs version 21.1.14
includes -O3. When I tried to build xemacs we got as far
as linking the temacs binary, but then that binary core
dumped with a bus error when it tried to load up the
initial elisp code. I reduced the optimization level to
-O2 and this problem went away, and the build of xemacs
completed without error.

This is basically an FYI rather than a bug report. The 
problem could be a matter of incorrect code in 
xemacs 21.1.14, a problem with the current version of
GNU ld as built on Solaris 2.6, or a problem in the
gcc optimizer. I suspect that it will be very difficult
to duplicate this problem :-) You would need a Solaris 2.6
ultra sparc box with the same set of OS patches as we have
installed, version R6.3 of X11 built with gcc 2.95, gcc
snapshot 14-May-2001 compiled with gcc snapshot 7-Mar-2001,
and etc.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: