vector alignment question

[Steve Ellcey]

I noticed that vectors are always aligned based on their size, i.e.  an
8 byte vector has an aligment of 8 bytes, 16 byte vectors an alignment
of 16, a 256 byte vector an alignment of 256, etc.

Is this really intended?

I looked in stor-layout.c and found:

      /* Always naturally align vectors.  This prevents ABI changes
         depending on whether or not native vector modes are supported.  */
      TYPE_ALIGN (type) = tree_low_cst (TYPE_SIZE (type), 0);

so it seems to be intentional, but it still seems odd to me, especially
for very large vectors.

Steve Ellcey
sje@cup.hp.com