Hi, I am trying to bootstrap of GCC 4.9 FSF branch with LTO on native Aarch64 , The bootstrap build results in compare errors.
Command line. ------------------------ gcc-4_9/configure --with-build-config=bootstrap-lto --disable-werror --enable-languages=c,c++,fortran --prefix=/work/vekumar/ltoinstall/ --with-gmp=/work//vekumar/installpre/installdir/--with-mpfr=/work//vekumar/installpre/installdir/ --with-mpc=/work/GCC_Team/vekumar/installpre/installdir/ --disable-werror --enable-languages=c,c++,fortran Result ---------- --snip-- Comparing stages 2 and 3 warning: gcc/cc1plus-checksum.o differs warning: gcc/cc1-checksum.o differs Bootstrap comparison failure! gcc/gimple.o differs gcc/tree-diagnostic.o differs gcc/gengtype-state.o differs gcc/tree-vectorizer.o differs gcc/passes.o differs gcc/dumpfile.o differs gcc/tree-cfg.o differs gcc/tree-eh.o differs gcc/reload1.o differs gcc/ipa.o differs gcc/build/gengtype-state.o differs gcc/build/ggc-none.o differs gcc/build/genconfig.o differs gcc/build/genpeep.o differs gcc/cp/parser.o differs libcpp/files.o differs libcpp/line-map.o differs libcpp/expr.o differs libcpp/directives.o differs libcpp/traditional.o differs libcpp/pch.o differs libcpp/macro.o differs make[2]: *** [compare] Error 1 ---snip--- As a First step I compared the "objump -D" dump between "stage2-gcc/gimple.o" and "stage3-gcc/gimple.o". Differences are in LTO sections .gnu.lto_.decls.0, .gnu.lto_.symtab. Ref: http://paste.ubuntu.com/7949238/ No differences when when using "objdump -d". Next I passed "-save-temps" to stage2 and stage3 builds and compared the assembly files. The differences are in strings dumped via .ascii and ,string directives. Next I checked the flags passed to the stage 2 and stage 3 builds. It is same and below is the flag set being passed. -save-temps -O2 -g -flto -flto=jobserver -frandom-seed=1 -ffat-lto-objects -DIN_GCC -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-forma t-attribute -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings Can you please suggest on how to fix/debug further these comparison failures in GCC 4.9? regards, Venkat.
