This may be a generic problem, though it's found on SH.
sh4-unknown-linux-gnu fails to bootstrap for a while with:
Comparing stages 2 and 3
warning: gcc/cc1-checksum.o differs
Bootstrap comparison failure!
gcc/cfgexpand.o differs
gcc/omp-low.o differs
The stage2 cfgexpand.o is compiled with -g -O2 -gtoggle and
the stage3 one is compiled with -g -O2. I've confirmed that
even the cross compiler gives the different results with/without
-g at -O2 for cfgexpand.
--
Summary: [4.5 Regression] combine behaves differently
with/without -g
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: kkojima at gcc dot gnu dot org
GCC target triplet: sh4-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41511
