http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61121
--- Comment #2 from Jim Michaels <jmichae3 at yahoo dot com> --- the commandline: "f:\x86_64-4.9.0-release-win32-sjlj-rt_v3-rev1\mingw64\bin\g++.exe" -Wall -Wextra -v -save-temps -m64 -static -O2 -fno-strict-aliasing -fwrapv -lstdc++ -ftree-parallelize-loops=n -floop-parallelize-all -ftree-loop-vectorize -ftree-slp-vectorize -O2 -Wall -W -Wextra -Xlinker -Map=gcc-substr-bug.map -std=c++11 -o "gcc-substr-bug.exe" "gcc-substr-bug.cpp" 2>gcc-substr-bug.err there is no .ii file of course.