3:38
Volume 3: Instruction Reference
clz
clz — Count Leading Zeros
Format:
(
qp
) clz
r
1
=
r
3
Description:
The number of leading zeros in GR
r
3
is placed in GR
r
1
.
An Illegal Operation fault is raised on processor models that do not support the
instruction. CPUID register 4 indicates the presence of the feature on the processor
model. See
Section 3.1.11, “Processor Identification Registers” on page 1:34
for
details. This capability may also be determined using the test feature (
tf
) instruction
using the
@clz
operand.
Operation:
if (PR[
qp
])
if (!instruction_implemented(CLZ))
illegal_operation_fault();
check_target_register(
r
1
);
tmp_val = 0;
do {
if (GR[
r
3
]{63 - tmp_val} != 0) break;
} while (+ < 63);
GR[
r
1
] = tmp_val;
GR[
r
1
].nat = GR[
r
3
].nat;
}
Interruptions:
Illegal Operation fault
Содержание Itanium 9150M
Страница 1: ......
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...
Страница 420: ......