http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54128
Bug #: 54128 Summary: GCC does not bootstrap on little endian mips due to mis-compare on tree-data-ref.c Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap AssignedTo: unassig...@gcc.gnu.org ReportedBy: s...@gcc.gnu.org A bootstrap using the latest GCC fails on a little endian MIPS system due to a compare failure. make[3]: Leaving directory `/home2/sje/gcc_native/obj-native/gcc' Comparing stages 2 and 3 warning: gcc/cc1plus-checksum.o differs warning: gcc/cc1-checksum.o differs Bootstrap comparison failure! gcc/tree-data-ref.o differs make[2]: *** [compare] Error 1 It looks like someone else saw this on a debian box and submitted a debian bug, http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=634881, but their fix was to workaround it by using -gtoggle for both the stage 2 and stage 3 builds. It is -gtoggle that is causing the difference. Comparing the two objects I see a small code gen difference in "analyze_subscript_affine". I have attached the preprocessed version of that source file to this bug report. Compiling it with C++ and "-g -O2 -fno-exceptions -fno-rtti -fno-common" in one case and adding -gtoggle in the second case should show the codegen difference. You may need -EL if using a mips GCC that does not generated little-endian by default.