* 0b010 to indicate "constant 1" (or 1.0)
* 0b011 is not needed.
-Evaluating efforts to encode 12 bit swizzle into less proved unsuccessful: 7^4 wcomes out to 2,400 which is larger than 11 bits
+Evaluating efforts to encode 12 bit swizzle into less proved unsuccessful: 7^4 comes out to 2,400 which is larger than 11 bits.
+
+Note that 7 options are needed (not 6) because the 7th option allows predicate masking to be encoded within the swizzle immediate.
Mode M is described in [[mv.vec]] and allows for merge and split of vectors.