# bitmask set
based on RV bitmanip singlebit set, instruction format similar to shift
-[[isa/fixedshift]]. bmext is actually covered already (shift-with-mask).
-however bitmask-invert is not, and set/clr are not covered, although they can ise the same Shift ALU.
+[[isa/fixedshift]]. bmext is actually covered already (shift-with-mask rldicl but only immediate version).
+however bitmask-invert is not, and set/clr are not covered, although they can use the same Shift ALU.
+
+bmext (RB) version is not the same as rldicl because bmext is a right shift by RC, where rldicl is a left rotate. for the immediate version this does not matter.
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