[Bug inline-asm/37492] New: optimization causes inline assembler to emit syntax errors

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

Compiling the following with -O0 works. Compiling with -O2 produces assembly
syntax errors.

Using built-in specs.
Target: i686-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-4.3.1-r1/work/gcc-4.3.1/configure --prefix=/usr
--bindir=/usr/i686-pc-linux-gnu/gcc-bin/4.3.1
--includedir=/usr/lib/gcc/i686-pc-linux-gnu/4.3.1/include
--datadir=/usr/share/gcc-data/i686-pc-linux-gnu/4.3.1
--mandir=/usr/share/gcc-data/i686-pc-linux-gnu/4.3.1/man
--infodir=/usr/share/gcc-data/i686-pc-linux-gnu/4.3.1/info
--with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/4.3.1/include/g++-v4
--host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --disable-altivec
--enable-nls --without-included-gettext --with-system-zlib --disable-checking
--disable-werror --enable-secureplt --disable-multilib --enable-libmudflap
--disable-libssp --enable-cld --enable-java-awt=gtk --with-arch=i686
--enable-languages=c,c++,java,treelang --enable-shared --enable-threads=posix
--enable-__cxa_atexit --enable-clocale=gnu
--with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.3.1-r1 p1.1'
Thread model: posix
gcc version 4.3.1 (Gentoo 4.3.1-r1 p1.1)


#include <stdio.h>

void test(unsigned int val)
{
  unsigned int res, resz;
  asm(
  " xorl %1, %1\n"
  " movl $0x12345678, %0\n"
  " bsrl %2, %0 ; setz %b1 "
  : "=r" (res), "=r" (resz)
  : "g" (val)
  );
  printf("val : %d\n", val);
  printf("res : %d\n", res);
  printf("resz: %d\n", resz);
}

int main()
{
  test(0);
  test(1 << 7);
  test(1 << 15);
  test(1 << 30);
  return 0;
}


-- 
           Summary: optimization causes inline assembler to emit syntax
                    errors
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: inline-asm
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: zeev dot tarantov at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37492