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: [email protected]
ReportedBy: [email protected]
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.
