Example 2, odd R field
value:
Before
execution
After
execution
ED
X'0123456789ABCDEP
X'0123456789ABCDEF'
(R)
xxxxxxxx
X'FEDCBA98'
CC xxxx x001
LAD
LOAD ABSOLUTE DOUBLEWORD
(Doubleword
index
alignment)
If the
effective
doubleword is
positive,
LOAD
ABSOLUTE
DOUBLEWORD loads the
32
low-order
bits
of
the
effective
doubleword
into
register
Ru1,
and
then
loads
the
32
high-
order
bits
of
the
effective
doubleword into
register
R.
If R is
an
odd
value,
the
result in
register
R is
the
32
high-order
bits
of
the
effective
doubleword. The
condition
code
set-
tings
are
based on
the
effective
doubleword,
rather
than
the final result in
register
R.
If
the
effective
doubleword is
negative,
LAD
forms
the
64-bit
two's complement
of
the
effective
doubleword,
loads
the
32
low-order
bits
of
the
two's complemented
double-
word into
register
Ru
1, and then loads
the
32
high-order
bits
of
the
two's
complemented
doubleword into
register
R.
If R is
an
odd
value,
the result in
register
R is
the
32
high-
order
bits
of
the
two's complemented doubleword. The
con-
dition
code
settings
are
based on
the
two's complement
of
.LL
__
CC_
...
-
_I
II
I
.1.1
.1,...
I I
••
11'1::
I::1II::~IIVl::
UUUUII::VVUIU,
IUHH:::r
IrIun
rne
nnol
resulT
In
register
R.
Fixed-point
overflow
occurs
if
the
effective
doubleword is
-2
63
(X'8000000000000000'), in which
case
the
result
in
registers
Rand
Rul
is
-2
63
and CC2 is
set
to
1;
otherwise,
CC2
is reset to
O.
Affected:
(R),
(Ru
1),CC2,
CC3,CC4
Trap:
Fixed-point
overflow
IED1
32
_
63
-Ru1i
IEDI
0
_
31
-R
Condition
code
settings:
2 3 4 Absolute
value
of
effective
doubleword
-
0 0 0 Zero
o
Nonzero
- 0
No
fixed-point
overflow
o
Fixed-point
overflow (sign
bit
on)
If
CC2
is
set to 1 and
the
fixed-point
arithmeti
c
trap
mask
(AM)
is
a 1,
the
BP
traps to
location
X'43'
after
execution
of
LOAD ABSOLUTE DOUBLEWORDi
otherwise,
the
BP
executes
the
next
instruction in
sequence.
Example 1,
even
R
field
value:
Before
execution
After
execution
ED
X'0123456789ABCDEF'
X'0123456789ABCDEF'
(R)
xxxxxxxx
X'01234567'
(Ru1) = xxxxxxxx
X'89ABCDEF'
CC
xxxx
xOlO
Example 2,
even
R
field
value:
Before
execution
After
execution
ED
X' FEDCBA9876543210' X' FEDCBA987654321
0'
(R)
xxxxxxxx
X'01234567'
(Rul) =
xxxxxxxx X'89ABCDFO'
CC
xxxx
xOlO
Example
3,
odd R
field
value:
Before
execution
After
execution
ED
- X'G.23456789ADCDEF X'G.23456789ADCDEF
(R)
xxxxxxxx
X'01234567'
CC
xxxx xOlO
LAS
LOAD AND
SET
(Word
index
alignment)
LOAD
AND
SET
loads
the
effective
word into
R.
If
the
effective
address is
equal
to
or
greater
than 16, a
one
is stored in
the
sign position
of
the
effective
loca-
tion.
If
the
effective
address is
equal
to
or
less than
15
(effective
location
is a
general
register),
the
sign
bit
remains
unchanged.
This
instruction
is
used to
interlock
multiple
processors from the simultaneous
execution
of
certai
n
secti
ons
of
code
or
from
the
si
mu
I
taneous
access
to
certain
tables.
Affected:
(R),
CC3,
CC4
EW-R
1
-EW
O
'
if
EA
~
16
Load/Store
Instructions 53
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