VBLOCK can be added later by using further VSX dedicated major opcodes
(EXT62, EXT60)
-* EXT00 - unused
+* EXT00 - unused (one instruction: attn)
* EXT01 - v3.1B prefix
* EXT02 - twi
* EXT03 - tdi
* EXT06 - vector
* EXT07 - mulli
* EXT09 - reserved
+* EXT17 - unused (2 instructions: sc, scv)
* EXT22 - reserved sandbox
* EXT56 - lq
* EXT57 - vector ld
* EXT56/57 - SV-C32-Swizzle
* EXT60/62 - VBLOCK
+Spare:
+
+* EXT09
+* EXT17
+* EXT22
+
# Major opcode map
Table 9: Primary Opcode Map (opcode bits 0:5)