An ia32 asm bug?

[H . J . Lu]

# gcc -S -O2 fs.c
fs.c: In function `foo':
fs.c:5: invalid lvalue in asm statement


-- 
H.J. Lu (hjl@gnu.org)
---
int
foo ()
{
int x;
__asm__("mov %%fs,%0":"=r" ((unsigned short) x));
return x;
}