https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58750
--- Comment #17 from Adam Hirst <adam at aphirst dot karoo.co.uk> --- I'm afraid to say that this issue is, in fact, not solved. [ 2 3 5 7 11 ] 5 [ 0 ] 1 Replacing "0" with "0_i8" in the implied do loop, as before, gives the correct output: [ 2 3 5 7 11 ] 5 [ 0 0 0 0 0 ] 5 This occurs for me regardless of the compilation flags set. Perhaps this was indeed fixed before; if so, this would be a regression since then. [adam@shimmer ~]$ gcc -v Using built-in specs. COLLECT_GCC=/usr/bin/gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/7.3.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp Thread model: posix gcc version 7.3.1 20180312 (GCC)