movmem pattern and missed alignment

[Paul Koning]

I have a movmem pattern in my target that pays attention to the alignment 
argument.

GCC isn't passing in the expected alignment part of the time.  I have this test 
case:

extern int *i, *j;
extern int iv[40], jv[40];

void f1(void)
{
    __builtin_memcpy (i, j, 32);
}

void f2(void)
{
    __builtin_memcpy (iv, jv, 32);
}

When the movmem pattern is called for f1, alignment is 1.  In f2, it is 2 (int 
is 2 bytes in pdp11) as expected.

The compiler clearly knows that int* points to aligned data, since it generates 
instructions that assume alignment (this is a strict-alignment target) when I 
dereference the pointer.  But somehow it gets it wrong for block move.

I also see this for the individual move operations that are generated for very 
short memcpy operations; if the count is 4, I get four move byte operations for 
f1, but two move word operations for f2.  

This seems like a bug.  Am I missing something?

        paul