[Bug inline-asm/51863] New: invlpg with -masm=intel generates memory operand size error in assembly stage

["th020394 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51863

             Bug #: 51863
           Summary: invlpg with -masm=intel generates memory operand size
                    error in assembly stage
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: inline-asm
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: th020394@gmail.com


The expected behavior would be to generate code analogous to that of the
default -masm=att, which uses no size prefixes to address the memory operand of
invlpg.

The actual behavior is that -masm=intel causes GCC to emit code that uses a
size prefix (like dword, byte, etc.) which causes an error in GAS when the code
is assembled.

The command that generates the error is:
gcc -masm=intel main.c

The same command without -masm=intel works.

Output of "gcc -v"
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.6.1/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.6.1-9ubuntu3' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr
--program-suffix=-4.6 --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++/4.6
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin
--enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=i686-linux-gnu
--host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3)

The system type is Linux Mint 12, but I've found the same bug in i686-elf for
GCC 4.6.2.