4:312
Volume 4: Base IA-32 Instruction Reference
POP—Pop a Value from the Stack
(Continued)
This action allows sequential execution of POP SS and MOV ESP, EBP instructions
without the danger of having an invalid stack during an interrupt. However, use of the
LSS instruction is the preferred method of loading the SS and ESP registers.
If the ESP register is used as a base register for addressing a destination operand in
memory, the POP instructions computes the effective address of the operand after it
increments the ESP register.
The POP ESP instruction increments the stack pointer (ESP) before data at the old top
of stack is written into the destination.
Operation
IF StackAddrSize = 32
THEN
IF OperandSize = 32
THEN
DEST
SS:ESP; (* copy a doubleword *)
ESP
ESP + 4;
ELSE (* OperandSize = 16*)
DEST
SS:ESP; (* copy a word *)
ESP
ESP + 2;
FI;
ELSE (* StackAddrSize = 16* )
IF OperandSize = 16
THEN
DEST
SS:SP; (* copy a word *)
SP
SP + 2;
ELSE (* OperandSize = 32 *)
DEST
SS:SP; (* copy a doubleword *)
SP
SP + 4;
FI;
FI;
Loading a segment register while in protected mode results in special checks and
actions, as described in the following listing. These checks are performed on the
segment selector and the segment descriptor it points to.
IF SS is loaded;
THEN
IF segment selector is null
THEN #GP(0);
FI;
IF segment selector index is outside descriptor table limits
OR segment selector's RPL
CPL
OR segment is not a writable data segment
OR DPL
CPL
THEN #GP(selector);
FI;
IF segment not marked present
THEN #SS(selector);
ELSE
SS
segment selector;
SS
segment descriptor;
Summary of Contents for ITANIUM ARCHITECTURE
Page 1: ......
Page 7: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 199: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 352: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 589: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 590: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 591: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 603: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...
Page 604: ......