[Bug target/41849] optimization fails when register variables are used for an interrupt

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41849

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gjl at gcc dot gnu.org,
                   |                            |hendrixgr at gmail dot com
          Component|rtl-optimization            |target
      Known to work|                            |4.5.0

--- Comment #1 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-04-20 19:45:54 UTC ---
Unfortunately, we don't see the exact command line.

I don't see this for 4.5.0, tried -O, -O2, -Os, -O3. All gives

foo:
/* prologue: function */
/* frame size = 0 */
/* stack size = 0 */
.L__stack_usage = 0
    sts timer0_h8_buf,r3
/* epilogue start */
    ret

Note that volatile on register variables does not work as expected. volatile is
meaningful for memory locations only.

As the addresses in your snipp indicate there is much more code in the module,
so presumably we don't see the proper source.