3:174
Volume 3: Instruction Reference
mov br
mov — Move Branch Register
Format:
(
qp
) mov
r
1
=
b
2
from_form
(
qp
) mov
b
1
=
r
2
pseudo-op
(
qp
) mov.
mwh
.
ih b
1
=
r
2
,
tag
13
to_form
(
qp
) mov.ret.
mwh
.
ih b
1
=
r
2
,
tag
13
return_form, to_form
Description:
The source operand is copied to the destination register.
In the from_form, the branch register specified by
b
2
is copied into GR
r
1
. The NaT bit
corresponding to GR
r
1
is cleared.
In the to_form, the value in GR
r
2
is copied into BR
b
1
. If the NaT bit corresponding to
GR
r
2
is 1, then a Register NaT Consumption fault is taken.
A set of hints can also be provided when moving to a branch register. These hints are
very similar to those provided on the
brp
instruction, and provide prediction
information about a future branch which may use the value being moved into BR
b
1
. The
return_form is used to provide the hint that this value will be used in a return-type
branch.
The values for the
mwh
whether hint completer are given in
. For a
description of the
ih
hint completer see the Branch Prediction instruction and
.
A pseudo-op is provided for copying a general register into a branch register when
there is no hint information to be specified. This is encoded with a value of 0 for
tag
13
and values corresponding to
none
for the hint completers.
Operation:
if (PR[
qp
]) {
if (from_form) {
check_target_register(
r
1
);
GR[
r
1
] = BR[
b
2
];
GR[
r
1
].nat = 0;
} else { // to_form
tmp_tag = IP + sign_ext((
timm
9
<< 4), 13);
if (GR[
r
2
].nat)
register_nat_consumption_fault(0);
BR[
b
1
] = GR[
r
2
];
branch_predict(
mwh
,
ih
, return_form, GR[
r
2
], tmp_tag);
}
}
Interruptions:
Illegal Operation fault
Register NaT Consumption fault
Table 2-39.
Move to BR Whether Hints
mwh
Completer
Move to BR Whether Hint
none
Ignore all hints
sptk
Static Taken
dptk
Dynamic
Содержание Itanium 9150M
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Страница 209: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault...
Страница 301: ...3 292 Volume 3 Pseudo Code Functions Intel Itanium Architecture Software Developer s Manual Rev 2 3...
Страница 405: ...3 396 Volume 3 Resource and Dependency Semantics...
Страница 406: ...3 397 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index...
Страница 407: ...3 398 Intel Itanium Architecture Software Developer s Manual Rev 2 3...
Страница 419: ...INDEX Index 12 Index for Volumes 1 2 3 and 4...
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