https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105533
--- Comment #3 from David Binderman <dcb314 at hotmail dot com> --- Asan, most of the checking flags, fortran and the -march setting not required. Current configure script is: ../trunk.20210101/configure \ --disable-multilib \ --disable-werror \ --with-pkgversion=$HASH \ --with-build-config=bootstrap-ubsan \ --enable-checking=yes \ --enable-languages=c,c++ sed 's;-O2;-O3;' < Makefile > Makefile.tmp diff Makefile Makefile.tmp mv Makefile.tmp Makefile >From the output of the bootstrap: Configuring stage 2 in x86_64-pc-linux-gnu/libgcc ../../trunk.20210101/gcc/poly-int.h:1089:5: runtime error: left shift of negative value -8 ../../trunk.20210101/gcc/poly-int.h:1089:5: runtime error: left shift of negative value -8 ../../trunk.20210101/gcc/expmed.cc:3288:26: runtime error: signed integer overflow: -9223372036854775808 - 1 cannot be represented in type 'long int' Configuring stage 2 in x86_64-pc-linux-gnu/libgomp