[Bug debug/47881] [4.6 Regression] -fcompare-debug failure (length) with -O -fno-dce -funroll-loops -fno-web

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47881

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org,
                   |                            |vmakarov at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-03-07 10:12:04 UTC ---
While this started with
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167390,
it looks just as it uncovered a latent IRA bug.
My guess is that the differences are related to ira-emit.c (change_loop)
creating
some new pseudos, whose live ranges then don't ignore debug insns (normally
debug insns would be changed or reset to avoid different lr ranges caused by
debug insns, but probably as this happens still within IRA it won't be
adjusted).