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Lds/les/lfs/lgs/lss-load far pointer, Lds/les/lfs/lgs/lss—load far pointer – Intel 253666-024US User Manual

Page 575

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Vol. 2A 3-529

INSTRUCTION SET REFERENCE, A-M

LDS/LES/LFS/LGS/LSS—Load Far Pointer

LDS/LES/LFS/LGS/LSS—Load Far Pointer

Description

Loads a far pointer (segment selector and offset) from the second operand (source
operand) into a segment register and the first operand (destination operand). The
source operand specifies a 48-bit or a 32-bit pointer in memory depending on the
current setting of the operand-size attribute (32 bits or 16 bits, respectively). The
instruction opcode and the destination operand specify a segment register/general-
purpose register pair. The 16-bit segment selector from the source operand is loaded
into the segment register specified with the opcode (DS, SS, ES, FS, or GS). The
32-bit or 16-bit offset is loaded into the register specified with the destination
operand.

Opcode

Instruction

64-Bit

Mode

Compat/

Leg Mode

Description

C5 /r

LDS

r16,m16:16

Invalid

Valid

Load DS:r16 with far pointer from

memory.

C5 /r

LDS

r32,m16:32

Invalid

Valid

Load DS:r32 with far pointer from

memory.

0F B2 /r

LSS r16,m16:16 Valid

Valid

Load SS:r16 with far pointer from

memory.

0F B2 /r

LSS r32,m16:32 Valid

Valid

Load SS:r32 with far pointer from

memory.

REX + 0F B2 /r LSS r64,m16:64 Valid

N.E.

Load SS:r64 with far pointer from

memory.

C4 /r

LES r16,m16:16 Invalid

Valid

Load ES:r16 with far pointer from

memory.

C4 /r

LES r32,m16:32 Invalid

Valid

Load ES:r32 with far pointer from

memory.

0F B4 /r

LFS r16,m16:16 Valid

Valid

Load FS:r16 with far pointer from

memory.

0F B4 /r

LFS r32,m16:32 Valid

Valid

Load FS:r32 with far pointer from

memory.

REX + 0F B4 /r LFS r64,m16:64 Valid

N.E.

Load FS:r64 with far pointer from

memory.

0F B5 /r

LGS

r16,m16:16

Valid

Valid

Load GS:r16 with far pointer from

memory.

0F B5 /r

LGS

r32,m16:32

Valid

Valid

Load GS:r32 with far pointer from

memory.

REX + 0F B5 /r LGS

r64,m16:64

Valid

N.E.

Load GS:r64 with far pointer from

memory.