[Bug rtl-optimization/50078] [4.6/4.7 Regression] combine wrong code: volatile accesses optimized out

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50078

--- Comment #5 from Steven Bosscher <steven at gcc dot gnu.org> 2011-09-11 
15:14:19 UTC ---
Actually it is not noop_move_p that's at fault here, but the disgusting hack
for NOOP_MOVE_INSN_CODE. The insn is marked as a NOOP_MOVE somewhere else in
combine.