the encoding embeds predication into the swizzle as well as constants 1/1.0 and 0/0.0
+As a Scalar instruction, mv.swiz and fmv.swiz operate on four 32-bit
+quantities, reducing this instruction to 2-in, 2-out pairs of 64-bit
+registers:
+
+| swizzle name | source | dest | half |
+|-- | -- | -- | -- |
+| X | RA | RT | lo-half |
+| Y | RA | RT | hi-half |
+| Z | RA+1 | RT+1 | lo-half |
+| W | RA+1 | RT+1 | hi-half |
+
+When RA=RT (in-place swizzle) any
+
# Format
| 0.5 |6.10|11.15|16.27|28.31| name |