Power ISA™ Version 2.03 - Power.org

Version 2.03
3.3.13.1.1 64-bit Fixed-Point Rotate Instructions
[Category: 64-Bit]
Rotate Left Doubleword Immediate then
Clear Left
MD-form
rldicl RA,RS,SH,MB (Rc=0)
rldicl. RA,RS,SH,MB (Rc=1)
30 RS RA sh mb 0 sh Rc
0 6 11 16 21 27 30 31
Rotate Left Doubleword Immediate then
Clear Right
MD-form
rldicr RA,RS,SH,ME (Rc=0)
rldicr. RA,RS,SH,ME (Rc=1)
30 RS RA sh me 1 sh Rc
0 6 11 16 21 27 30 31
n sh 5 || sh 0:4
r ROTL 64 ((RS), n)
b mb 5 || mb 0:4
m MASK(b, 63)
RA r & m
The contents of register RS are rotated 64 left SH bits.
A mask is generated having 1-bits from bit MB through
bit 63 and 0-bits elsewhere. The rotated data are
ANDed with the generated mask and the result is
placed into register RA.
Special Registers Altered:
CR0
(if Rc=1)
Extended Mnemonics:
Examples of extended mnemonics for Rotate Left Doubleword
Immediate then Clear Left:
Extended:
Equivalent to:
extrdi Rx,Ry,n,b rldicl Rx,Ry,b+n,64-n
srdi Rx,Ry,n rldicl Rx,Ry,64-n,n
clrldi Rx,Ry,n rldicl Rx,Ry,0,n
Programming Note
rldicl can be used to extract an n-bit field that starts
at bit position b in register RS, right-justified into
register RA (clearing the remaining 64-n bits of
RA), by setting SH=b+n and MB=64-n. It can be
used to rotate the contents of a register left (right)
by n bits, by setting SH=n (64-n) and MB=0. It can
be used to shift the contents of a register right by n
bits, by setting SH=64-n and MB=n. It can be used
to clear the high-order n bits of a register, by setting
SH=0 and MB=n.
Extended mnemonics are provided for all of these
uses; see Appendix D, “Assembler Extended Mnemonics”
on page 313.
n sh 5 || sh 0:4
r ROTL 64 ((RS), n)
e me 5 || me 0:4
m MASK(0, e)
RA r & m
The contents of register RS are rotated 64 left SH bits.
A mask is generated having 1-bits from bit 0 through bit
ME and 0-bits elsewhere. The rotated data are ANDed
with the generated mask and the result is placed into
register RA.
Special Registers Altered:
CR0
(if Rc=1)
Extended Mnemonics:
Examples of extended mnemonics for Rotate Left Doubleword
Immediate then Clear Right:
Extended:
Equivalent to:
extldi Rx,Ry,n,b rldicr Rx,Ry,b,n-1
sldi Rx,Ry,n rldicr Rx,Ry,n,63-n
clrrdi Rx,Ry,n rldicr Rx,Ry,0,63-n
Programming Note
rldicr can be used to extract an n-bit field that
starts at bit position b in register RS, left-justified
into register RA (clearing the remaining 64-n bits of
RA), by setting SH=b and ME=n-1. It can be used
to rotate the contents of a register left (right) by n
bits, by setting SH=n (64-n) and ME=63. It can be
used to shift the contents of a register left by n bits,
by setting SH=n and ME=63-n. It can be used to
clear the low-order n bits of a register, by setting
SH=0 and ME=63-n.
Extended mnemonics are provided for all of these
uses (some devolve to rldicl); see Appendix D,
“Assembler Extended Mnemonics” on page 313.
Chapter 3. Fixed-Point Processor
77