Volume 4: Base IA-32 Instruction Reference
4:359
SGDT/SIDT—Store Global/Interrupt Descriptor Table Register
Description
Stores the contents of the global descriptor table register (GDTR) or the interrupt
descriptor table register (IDTR) in the destination operand. The destination operand is a
pointer to 6-byte memory location. If the operand-size attribute is 32 bits, the 16-bit
limit field of the register is stored in the lower 2 bytes of the memory location and the
32-bit base address is stored in the upper 4 bytes. If the operand-size attribute is 16
bits, the limit is stored in the lower 2 bytes and the 24-bit base address is stored in the
third, fourth, and fifth byte, with the sixth byte is filled with 0s.
The SGDT and SIDT instructions are useful only in operating-system software; however,
they can be used in application programs.
Operation
IF Itanium System Environment THEN IA-32_Intercept(INST,SGDT/SIDT);
IF instruction is IDTR
THEN
IF OperandSize = 16
THEN
DEST[0:15]
IDTR(Limit);
DEST[16:39]
IDTR(Base); (* 24 bits of base address loaded; *)
DEST[40:47]
0;
ELSE (* 32-bit Operand Size *)
DEST[0:15]
IDTR(Limit);
DEST[16:47]
IDTR(Base); (* full 32-bit base address loaded *)
FI;
ELSE (* instruction is SGDT *)
IF OperandSize = 16
THEN
DEST[0:15]
GDTR(Limit);
DEST[16:39]
GDTR(Base); (* 24 bits of base address loaded; *)
DEST[40:47]
0;
ELSE (* 32-bit Operand Size *)
DEST[0:15]
GDTR(Limit);
DEST[16:47]
GDTR(Base); (* full 32-bit base address loaded *)
FI;
FI;
Flags Affected
None.
Additional Itanium System Environment Exceptions
IA-32_Intercept
Instruction Intercept for SIDT and SGDT.
Opcode
Instruction
Description
0F 01 /0
SGDT
m
Store GDTR to
m
0F 01 /1
SIDT
m
Store IDTR to
m
Содержание ITANIUM ARCHITECTURE
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Страница 7: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 199: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Страница 269: ...4 262 Volume 4 Base IA 32 Instruction Reference LES Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 270: ...Volume 4 Base IA 32 Instruction Reference 4 263 LFS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 273: ...4 266 Volume 4 Base IA 32 Instruction Reference LGS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 288: ...Volume 4 Base IA 32 Instruction Reference 4 281 LSS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 352: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Страница 368: ...Volume 4 Base IA 32 Instruction Reference 4 361 SHL SHR Shift Instructions See entry for SAL SAR SHL SHR ...
Страница 373: ...4 366 Volume 4 Base IA 32 Instruction Reference SIDT Store Interrupt Descriptor Table Register See entry for SGDT SIDT ...
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Страница 590: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Страница 591: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 603: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...
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