[mpich2-dev] [PATCH 1/1] Issue 4120: Fix attr alignment check from MPI_Aint to long alignment

[Darius Buntinas]

Actually long and pointers are not necessarily the same size.  My K&R 
ANSI C book says:

"The compiler is free to choose appropriate sizes for its own hardware, 
subject only to the restriction that shorts and ints are at least 16 
bits, longs are at least 32 bits, and short is no longer than int, which 
is no longer than long."

C99 defines intptr_t for this... but you can't depend on a compiler 
being C99.

-d

On 03/24/2008 04:12 PM, Jeff Parker wrote:
> 
> On 03/23/2008 04:26 PM, William Gropp wrote:
> "This one is system-specific - some systems will require the MPI_Aint 
> alignment.   This should probably be abstracted out and set based on the 
> requirements of the system."
> 
> Are you saying that on some systems, "long" is not the size of a 
> pointer, whereas "MPI_Aint" is?  Are there really such systems that we 
> need to be concerned about?  Standard C specifies that long and pointers 
> are the same size.