[Bug tree-optimization/36226] New: Optimization corrupts volatile function pointer return handling

[Bug tree-optimization/36226] New: Optimization corrupts volatile function pointer return handling

[mbenedict at aclaratech dot com]

When using a volatile function pointer and compiling with -O2 optimization, the
resulting program will not correctly return from the function pointer but will
instead jump to another point of the program.  I have been able to reproduce
this behavior with gcc 3.4.6, 4.0.2 and the x86 locally hosted 4.1.1 version of
gcc.

Originally the bug was discovered with:
$ powerpc-603-linux-gnu-gcc -v
Reading specs from
/opt/crosstool/gcc-3.4.5-glibc-2.3.6/powerpc-603-linux-gnu/lib/gcc/powerpc-603-linux-gnu/3.4.5/specs
Configured with:
/home/mbenedict/src/crosstool-0.43/build/powerpc-603-linux-gnu/gcc-3.4.5-glibc-2.3.6/gcc-3.4.5/configure
--target=powerpc-603-linux-gnu --host=i686-host_pc-linux-gnu
--prefix=/opt/crosstool/gcc-3.4.5-glibc-2.3.6/powerpc-603-linux-gnu
--with-cpu=603 --enable-cxx-flags=-mcpu=603
--with-headers=/opt/crosstool/gcc-3.4.5-glibc-2.3.6/powerpc-603-linux-gnu/powerpc-603-linux-gnu/include
--with-local-prefix=/opt/crosstool/gcc-3.4.5-glibc-2.3.6/powerpc-603-linux-gnu/powerpc-603-linux-gnu
--disable-nls --enable-threads=posix --enable-symvers=gnu --enable-__cxa_atexit
--enable-languages=c --enable-shared --enable-c99 --enable-long-long
Thread model: posix
gcc version 3.4.5

I will attach the .i file that reproduces this condition in the first comment
(I can't seem to attach from the new bug screen).


-- 
           Summary: Optimization corrupts volatile function pointer return
                    handling
           Product: gcc
           Version: 3.4.5
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mbenedict at aclaratech dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: powerpc-603-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36226

[Bug tree-optimization/36226] Optimization corrupts volatile function pointer return handling

[mbenedict at aclaratech dot com]

------- Comment #1 from mbenedict at aclaratech dot com  2008-05-12 22:48 -------
Created an attachment (id=15632)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15632&action=view)
File that reproduces the problem

Note also that when optimizing (-O2) the assembly comment" # XXX - This
assembly line is missing when optimized" goes away


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36226

[Bug tree-optimization/36226] Optimization corrupts volatile function pointer return handling

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2008-05-12 22:49 -------
volatile here means no return and no standard C meaning IIRC.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36226

[Bug middle-end/36226] Optimization corrupts volatile function pointer return handling

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2008-12-29 02:31 -------
volatile here means noreturn.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36226