Minimum target alignment for a datatype

[Chris Lattner]

Hi All,
I'm trying to determine (in target-independent code) what the  
*minimum* target alignment of a type is.  For example, on darwin,  
double's are normally 4-byte aligned, but are 8-byte aligned in some  
cases (e.g. when they are the first element of a struct).  TYPE_ALIGN  
on a double returns 8 bytes, is there any way to find out that they  
may end up being aligned to a 4-byte boundary?

Thanks,

-Chris