[Bug target/39386] [avr] different computation results for O1 and O0 executables

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39386

--- Comment #11 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-07-23 13:48:14 UTC ---
Created attachment 24814
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24814
Minimal testcase

Minimal testcase that also miscompiles for newer versions of the compiler like
4.5.2 or 4.6.1.

Compiles with -Os to

shift:
    rjmp 2f
1:    lsl r24
    rol r25
2:    dec r24
    brpl 1b
    ret