FLD1, FLDL2T, FLDL2E, FLDPI, FLDLG2, FLDLN2, FLDZs (Intel x86/64 assembly instruction)

모두의 코드
FLD1, FLDL2T, FLDL2E, FLDPI, FLDLG2, FLDLN2, FLDZs (Intel x86/64 assembly instruction)

작성일 : 2020-09-01 이 글은 861 번 읽혔습니다.

FLD1, FLDL2T, FLDL2E, FLDPI, FLDLG2, FLDLN2, FLDZ

Load Constant

참고 사항

아래 표를 해석하는 방법은 x86-64 명령어 레퍼런스 읽는 법 글을 참조하시기 바랍니다.

Opcode*	Instruction	64-Bit Mode	Compat/ Leg Mode	Description
D9 E8	FLD1	Valid	Valid	Push +1.0 onto the FPU register stack.
D9 E9	FLDL2T	Valid	Valid	Push log210 onto the FPU register stack.
D9 EA	FLDL2E	Valid	Valid	Push log2e onto the FPU register stack.
D9 EB	FLDPI	Valid	Valid	Push onto the FPU register stack.
D9 EC	FLDLG2	Valid	Valid	Push log102 onto the FPU register stack.
D9 ED	FLDLN2	Valid	Valid	Push loge2 onto the FPU register stack.
D9 EE	FLDZ	Valid	Valid	Push +0.0 onto the FPU register stack.

* See IA-32 Architecture Compatibility section below

Description

Push one of seven commonly used constants (in double extended-precision floating-point format) onto the FPU register stack. The constants that can be loaded with these instructions include +1.0, +0.0, log210, log2e, , log102, and loge2. For each constant, an internal 66-bit constant is rounded (as specified by the RC field in the FPU control word) to double extended-precision floating-point format. The inexact-result exception (#P) is not generated as a result of the rounding, nor is the C1 flag set in the x87 FPU status word if the value is rounded up.

See the section titled "Approximation of Pi" in Chapter 8 of the Intel(R) 64 and IA-32 Architectures Software Devel-oper's Manual, Volume 1, for a description of the constant.

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

IA-32 Architecture Compatibility

When the RC field is set to round-to-nearest, the FPU produces the same constants that is produced by the Intel 8087 and Intel 287 math coprocessors.

Operation

TOP <- TOP - 1;
ST(0) <- CONSTANT;

FPU Flags Affected

C1 Set to 1 if stack overflow occurred; otherwise, set to 0.

C0, C2, C3 Undefined.

Floating-Point Exceptions

#IS Stack overflow occurred.

Protected Mode Exceptions

#NM

CR0.EM[bit 2] or CR0.TS[bit 3] = 1.

#MF

If there is a pending x87 FPU exception.