vrlwmi
Vector Rotate Left Word then Mask Insert VX-form
Rotates the contents of each word element in a vector left by a specified number of bits and inserts the result into another vector under control of a mask.
Details
The vrlwmi instruction rotates each word element in VSR[VRA+32] left by the number of bits specified in the corresponding word element of VSR[VRB+32]. It then inserts the rotated data into the corresponding word element of VSR[VRT+32] under control of a mask generated from bits 11:15 and 19:23 of VSR[VRB+32].
Pseudocode Operation
if MSR.VEC=0 then
Vector_Unavailable()
do i = 0 to 3
src1.word[0] ← VSR[VRA+32].word[i]
src1.word[1] ← VSR[VRA+32].word[i]
src2 ← VSR[VRB+32].word[i]
src3 ← VSR[VRT+32].word[i]
b ← src2.bit[11:15]
e ← src2.bit[19:23]
n ← src2.bit[27:31]
r ← src1.bit[n:n+31]
m ← MASK(b, e)
VSR[VRT+32].word[i] ← (r & m) | (src3 & ¬m)Programming Note
The vrlwmi instruction is useful for performing masked insertions after rotating word elements. Ensure that the mask bits (11:15 and 19:23) are set correctly to achieve the desired insertion pattern. This instruction operates on vector registers, so ensure that the Vector Facility is enabled in the Machine State Register (MSR).
Example
Encoding
Operands
-
VRT
Target Vector Register -
VRA
Source Vector Register -
VRB
Source Vector Register