In theory, the last two should stages produce the same results,
which `make compare` can check.
With CFLAGS:
-march=i686 -mtune=pentium4 -O2 -fomit-frame-pointer -funroll-loops
Comparing stage2 and stage3 of the compiler
(...)
Bootstrap comparison failure!
./bb-reorder.o differs
./builtins.o differs
./caller-save.o differs
./calls.o differs
./combine.o differs
./cse.o differs
./ddg.o differs
./dwarf2out.o differs
./flow.o differs
./global.o differs
./loop.o differs
./real.o differs
./recog.o differs
./reg-stack.o differs
./regclass.o differs
./regrename.o differs
./reload.o differs
./reload1.o differs
./rtlanal.o differs
./simplify-rtx.o differs
./tree-dfa.o differs
./tree-phinodes.o differs
./tree-ssa-live.o differs
./tree-ssa-loop-im.o differs
./tree-ssa-loop-ivopts.o differs
./tree-vect-transform.o differs
ada/ali.o differs
ada/binde.o differs
ada/bindgen.o differs
ada/checks.o differs
ada/exp_aggr.o differs
ada/exp_ch5.o differs
ada/g-speche.o differs
ada/inline.o differs
ada/s-carun8.o differs
ada/sem_case.o differs
ada/sem_ch3.o differs
ada/sem_ch8.o differs
ada/sem_maps.o differs
ada/tree_io.o differs
ada/uintp.o differs
cp/mangle.o differs
cp/pt.o differs
build/gensupport.o differs
make[1]: *** [gnucompare] Error 1
# gcc -v
Reading specs from /usr/lib/gcc/i686-pld-linux/4.0.0/specs
Target: i686-pld-linux
Configured with: ../configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --infodir=/usr/share/info --mandir=/usr/share/man
--enable-shared --enable-threads=posix --enable-__cxa_atexit
--enable-languages=c,c++,ada,java --enable-c99 --enable-long-long
--disable-multilib --enable-nls --with-gnu-as --with-gnu-ld
--with-demangler-in-ld --with-system-zlib --with-slibdir=/lib --without-x
--enable-cmath --enable-libgcj --enable-libgcj-multifile
--enable-libgcj-database --enable-gtk-cairo i686-pld-linux
Thread model: posix
gcc version 4.0.0 20050319 (prerelease) (PLD Linux)
--
Summary: bootstrap comparision fails with -funroll-loops.
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: other
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pluto at pld-linux dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-pld-linux
GCC host triplet: i686-pld-linux
GCC target triplet: i686-pld-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20586
