Fixed-point rotate and shift instructions

The fixed-point rotate and shift instructions rotate the contents of a register.

The fixed-point processor performs rotate operations on data from a GPR. These instructions rotate the contents of a register in one of the following ways:

• The result of the rotation is inserted into the target register under the control of a mask. If the mask bit is 1, the associated bit of the rotated data is placed in the target register. If the mask bit is 0, the associated data bit in the target register is unchanged.
• The result of the rotation is ANDed with the mask before being placed into the target register.

The rotate left instructions allow (in concept) right-rotation of the contents of a register. For 32-bit implementations, an n-bit right-rotation can be performed by a left-rotation of 32-n.

The fixed-point shift instructions logically perform left and right shifts. The result of a shift instruction is placed in the target register under the control of a generated mask.

Some POWER® family shift instructions involve the MQ register. This register is also updated.

Extended mnemonics are provided for extraction, insertion, rotation, shift, clear, and clear left and shift left operations.