Encoding:

POOL32A

000000

rt

rs

sa

0

ROTR

0011000000

6

5

5

5

1

10

Format: 

ROTR rt, rs, sa

SmartMIPS Crypto, microMIPS

Rotate Word Right

Purpose:

Rotate Word Right

To execute a logical right-rotate of a word by a fixed number of bits.

Description: 

 GPR[rt] = GPR[rs] <=(right) sa

The contents of the low-order 32-bit word of GPR rs are rotated right; the word result is sign-extended and placed in

GPR rt. The bit-rotate amount is specified by sa.

Restrictions:

If GPR rt does not contain a sign-extended 32-bit value (bits 63..31 equal), then the result of the operation is

UNPREDICTABLE.

Operation: 

if NotWordValue(GPR[rt]) or
   ((ArchitectureRevision() < 2) and (Config3SM = 0)) then
   UNPREDICTABLE 
endif
s = sa
temp = GPR[rs]s-1..0 || GPR[rs]31..s
GPR[rt] = sign_extend(temp)

Exceptions:

Reserved Instruction