FINCSTP

Increment Stack-Top Pointer

참고 사항

Description

Adds one to the TOP field of the FPU status word (increments the top-of-stack pointer). If the TOP field contains a 7, it is set to 0. The effect of this instruction is to rotate the stack by one position. The contents of the FPU data registers and tag register are not affected. This operation is not equivalent to popping the stack, because the tag for the previous top-of-stack register is not marked empty.

This instruction's operation is the same in non-64-bit modes and 64-bit mode.

Operation

IF TOP = 7
    THEN TOP <- 0;
    ELSE TOP <- TOP + 1;
FI;

FPU Flags Affected

The C1 flag is set to 0. The C0, C2, and C3 flags are undefined.

Floating-Point Exceptions

None

Protected Mode Exceptions

#NM

• CR0.EM[bit 2] or CR0.TS[bit 3] = 1.

#MF

• If there is a pending x87 FPU exception.

#UD

• If the LOCK prefix is used.

Real-Address Mode Exceptions

Same exceptions as in protected mode.

Virtual-8086 Mode Exceptions

Same exceptions as in protected mode.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

Same exceptions as in protected mode.

첫 댓글을 달아주세요!

강좌에 관련 없이 궁금한 내용은 여기를 사용해주세요

다음으로 로그인

또는 직접 입력하세요 (댓글 수정시 비밀번호가 필요합니다)

댓글 달기

댓글을 불러오는 중입니다..