I have added binaries compiled with my MinGW with -O2 and -O0, and compiled with the TestBot compiler. I also added assembly files and compiler version information. All of this is available at:
http://fgouget.free.fr/tmp/dinput8-dinput.tar.xz
For immediate reference: My compiler is the Debian Testing compiler (buggy): $ i686-w64-mingw32-gcc --version i686-w64-mingw32-gcc (GCC) 5.3.1 20160205 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
The TestBot compiler is the Debian 7.4 compiler (not buggy): $ i686-w64-mingw32-gcc --version i686-w64-mingw32-gcc (GCC) 4.6.3 Copyright (C) 2011 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
And the WineTest.exe binary is compiled with the Debian 8 compiler which is presumably close to the current Debian Testing one.