Intel 253666-024US - Manual (Page 126)

3-80 Vol. 2A BTC—Bit Test and Complement
INSTRUCTION SET REFERENCE, A-M
#AC(0) If alignment checking is enabled and an unaligned memory
reference is made.
#UD If the LOCK prefix is used but the destination is not a memory
operand.
Compatibility Mode Exceptions
Same exceptions as in protected mode.
64-Bit Mode Exceptions
#SS(0) If a memory address referencing the SS segment is in a non-
canonical form.
#GP(0) If the memory address is in a non-canonical form.
#PF(fault-code) If a page fault occurs.
#AC(0) If alignment checking is enabled and an unaligned memory
reference is made while the current privilege level is 3.
#UD If the LOCK prefix is used but the destination is not a memory
operand.