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3-522 Vol. 2A LAR—Load Access Rights Byte
INSTRUCTION SET REFERENCE, A-M
ZF = 0;
ELSE
IF SegmentDescriptor(Type)
≠ conforming code segment
and (CPL > DPL) or (RPL > DPL)
or segment type is not valid for instruction
THEN
ZF ← 0
ELSE
TEMP ← Read segment descriptor ;
IF OperandSize
= 64
THEN
DEST ← (ACCESSRIGHTWORD(TEMP) AND 00000000_00FxFF00H);
ELSE (* OperandSize
= 32*)
DEST ← (ACCESSRIGHTWORD(TEMP) AND 00FxFF00H);
ELSE (* OperandSize
= 16 *)
DEST ← (ACCESSRIGHTWORD(TEMP) AND FF00H);
FI;
FI;
FI:
Flags Affected
The ZF flag is set to 1 if the access rights are loaded successfully; otherwise, it is set
to 0.
Protected Mode Exceptions
#GP(0) If a memory operand effective address is outside the CS, DS,
ES, FS, or GS segment limit.
If the DS, ES, FS, or GS register is used to access memory and it
contains a NULL segment selector.
#SS(0) If a memory operand effective address is outside the SS
segment limit.
#PF(fault-code) If a page fault occurs.
#AC(0) If alignment checking is enabled and the memory operand effec-
tive address is unaligned while the current privilege level is 3.
#UD If the LOCK prefix is used.
Real-Address Mode Exceptions
#UD The LAR instruction is not recognized in real-address mode.