Volume 3: Instruction Reference
3:261
tbit
tbit — Test Bit
Format:
(
qp
) tbit.
trel
.
ctype p
1
,
p
2
=
r
3
,
pos
6
Description:
The bit specified by the
pos
6
immediate is selected from GR
r
3
. The selected bit forms a
single bit result either complemented or not depending on the
trel
completer. This result
is written to the two predicate register destinations
p
1
and
p
2
. The way the result is
written to the destinations is determined by the compare type specified by
ctype
. See
the Compare instruction and
The
trel
completer values
.
nz and
.
z indicate non-zero and zero sense of the test. For
normal and unc types, only the
.
z value is directly implemented in hardware; the
.
nz
value is actually a pseudo-op. For it, the assembler simply switches the predicate target
specifiers and uses the implemented relation. For the parallel types, both relations are
implemented in hardware.
If the two predicate register destinations are the same (
p
1
and
p
2
specify the same
predicate register), the instruction will take an Illegal Operation fault, if the qualifying
predicate is set, or if the compare type is unc.
Table 2-53.
Test Bit Relations for Normal and unc tbits
trel
Test Relation
Pseudo-op of
nz
selected bit == 1
z
p
1
p
2
z
selected bit == 0
Table 2-54.
Test Bit Relations for Parallel tbits
trel
Test Relation
nz
selected bit == 1
z
selected bit == 0
Summary of Contents for Itanium 9150M
Page 1: ......
Page 209: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault...
Page 405: ...3 396 Volume 3 Resource and Dependency Semantics...
Page 406: ...3 397 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index...
Page 407: ...3 398 Intel Itanium Architecture Software Developer s Manual Rev 2 3...
Page 419: ...INDEX Index 12 Index for Volumes 1 2 3 and 4...
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