http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58314
--- Comment #13 from Oleg Endo <olegendo at gcc dot gnu.org> ---
BTW, using the "m" constraint for QImode and HImode in inline asm is dangerous.
It's very easy to create wrong code with it. For example:
struct test_struct
{
unsigned short a, b, c, d;
};
void test (struct test_struct* s, unsigned short* result)
{
unsigned short r;
__asm__ __volatile__ (
"mov.w %1,%0"
: "=&r" (r)
: "m" (s->b)
: "memory");
*result = r;
}
will compile to:
_test:
! 39 "sh_tmp.cpp" 1
mov.w @(2,r4),r1 ! Invalid mov.w for non-SH2A.
! 0 "" 2
rts
mov.w r1,@r5
I think in order to avoid surprises and simplify debugging of such code
something like the patch in comment #11 should be added to trunk.
