https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62077
--- Comment #11 from Venkataramanan <venkataramanan.kumar at amd dot com> --- I am also trying to fix LTO bootstrap compare failure in Aarch64. Bootstrap compare failure is not occurring in GCC FSF trunk (tested on aarch64 as well as x86_64 machine). Now I am doing one more round of bisecting to see which revision fixes this (or) first time compare not seen. Also I tried to recompile gimple.o which was miscomparing and also dump the gimple and IPA IR. I found that in GCC trunk there are no differences between stage2 and stage3 dumps. But with GCC 4.9 there are some differences, Stage2 (prev-gcc) vs stage3 (gcc) Very first dump file is gimple.c.001t.tu The number of @numbers are more in stage2 @103184 identifier_node strg: debug_ready_dispatch lngt: 20 Stage3 @103169 identifier_node strg: debug_ready_dispatch lngt: 20 Also gimple.c.048i.inline showed differences in Min size. (--Snip--) < min size: 6 --- > min size: 0 6590c6590 < min size: 14 --- > min size: 0 6607c6607 < min size: 28 (--Snip--) In gimple-fold.c.000i.cgraph (--Snip--) < _Z25gimple_build_omp_continueP9tree_nodeS0_/761 (gimple_build_omp_continue(tree_node*, tree_node*)) @0x3ff7ebda548 --- > _Z25gimple_build_omp_continueP9tree_nodeS0_/761 > (gimple_build_omp_continue(tree_node*, tree_node*)) @0x3ff92b5a548 28865c28865 (--Snip--) why do these dumps show differences? The other tree optimization dumps don't show any difference.