[Bug rtl-optimization/51447] [4.4/4.5/4.6/4.7 Regression] global register variable definition incorrectly removed as dead code

[bonzini at gnu dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51447

--- Comment #8 from Paolo Bonzini <bonzini at gnu dot org> 2011-12-15 12:01:25 
UTC ---
For ud_dce it's simplest to add/remove fake edges around it.  For 4.8 it could
be worthwhile to try adding fake edges around all RTL passes (at least those
running in cfglayout mode) and see what breaks...