The original motivation for Indexed REMAP was to mitigate the need to add
an expensive `mv.x` to the Scalar ISA, which was likely to be rejected as
-a stand-alone instruction. Usually a Vector ISA would add a non-conflicting
+a stand-alone instruction
+(`GPR(RT) <- GPR(GPR(RA))`). Usually a Vector ISA would add a non-conflicting
variant (as in VSX `vperm`) but it is common to need to permute by source,
with the risk of conflict, that has to be resolved, for example, in AVX-512
with `conflictd`.