[Bug target/55940] Incorrect code for accessing parameters with 32-bit Intel hosts

[fm3 at os dot inf.tu-dresden.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55940

--- Comment #5 from Frank Mehnert <fm3 at os dot inf.tu-dresden.de> 2013-01-15 15:03:14 UTC ---
Actually I was able to reproduce generating the buggy code. My gcc version:

Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.2-5'
--with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --with-arch-32=i586 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Debian 4.7.2-5) 

I used the memobj-r0drv.i file from the above ticket and used the following
command line:

gcc -Os -m32 -c -o memobj-r0drv.o memobj-r0drv.i -mpreferred-stack-boundary=2

The -mpreferred-stack-boundary=2 is essential! Using this command line, the
same wrong code is generated (parameter is assumed to be passed in the EDI
register).