http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56909
--- Comment #16 from Arthur Zhang <mail2arthur at gmail dot com> 2013-04-18 14:48:50 UTC --- (In reply to comment #15) > > Why below output has '-march=pentiumpro'? > > I think it's the autodetected arch, but maybe I'm confused. Never mind. If you mean autodetected arch of the running PC (which has i7 CPU), then I think it is not, since for gcc v4.7.2 (which is built with only --build=mingw32): sh-3.1$ gcc -v -o t.exe test.c Using built-in specs. COLLECT_GCC=c:\MinGW\bin\gcc.exe COLLECT_LTO_WRAPPER=c:/mingw/bin/../libexec/gcc/mingw32/4.7.2/lto-wrapper.exe Target: mingw32 Configured with: ../gcc-4.7.2/configure --enable-languages=c,c++,ada,fortran,obj c,obj-c++ --disable-sjlj-exceptions --with-dwarf2 --enable-shared --enable-libgo mp --disable-win32-registry --enable-libstdcxx-debug --disable-build-poststage1- with-cxx --enable-version-specific-runtime-libs --build=mingw32 --prefix=/mingw Thread model: win32 gcc version 4.7.2 (GCC) COLLECT_GCC_OPTIONS='-v' '-o' 't.exe' '-mtune=i386' '-march=i386' ...