DIVSD — Divide Scalar Double Precision Floating-Point Value

Opcode/Instruction	Op / En	64/32 bit Mode Support	CPUID Feature Flag	Description
F2 0F 5E /r DIVSD xmm1, xmm2/m64	A	V/V	SSE2	Divide low double precision floating-point value in xmm1 by low double precision floating-point value in xmm2/m64.
VEX.LIG.F2.0F.WIG 5E /r VDIVSD xmm1, xmm2, xmm3/m64	B	V/V	AVX	Divide low double precision floating-point value in xmm2 by low double precision floating-point value in xmm3/m64.
EVEX.LLIG.F2.0F.W1 5E /r VDIVSD xmm1 {k1}{z}, xmm2, xmm3/m64{er}	C	V/V	AVX512F	Divide low double precision floating-point value in xmm2 by low double precision floating-point value in xmm3/m64.

Instruction Operand Encoding ¶

Op/En	Tuple Type	Operand 1	Operand 2	Operand 3	Operand 4
A	N/A	ModRM:reg (r, w)	ModRM:r/m (r)	N/A	N/A
B	N/A	ModRM:reg (w)	VEX.vvvv (r)	ModRM:r/m (r)	N/A
C	Tuple1 Scalar	ModRM:reg (w)	EVEX.vvvv (r)	ModRM:r/m (r)	N/A

Description ¶

Divides the low double precision floating-point value in the first source operand by the low double precision floating-point value in the second source operand, and stores the double precision floating-point result in the destination operand. The second source operand can be an XMM register or a 64-bit memory location. The first source and destination are XMM registers.

128-bit Legacy SSE version: The first source operand and the destination operand are the same. Bits (MAXVL-1:64) of the corresponding ZMM destination register remain unchanged.

VEX.128 encoded version: The first source operand is an xmm register encoded by VEX.vvvv. The quadword at bits 127:64 of the destination operand is copied from the corresponding quadword of the first source operand. Bits (MAXVL-1:128) of the destination register are zeroed.

EVEX.128 encoded version: The first source operand is an xmm register encoded by EVEX.vvvv. The quadword element of the destination operand at bits 127:64 are copied from the first source operand. Bits (MAXVL-1:128) of the destination register are zeroed.

EVEX version: The low quadword element of the destination is updated according to the writemask.

Software should ensure VDIVSD is encoded with VEX.L=0. Encoding VDIVSD with VEX.L=1 may encounter unpredictable behavior across different processor generations.

Operation ¶

VDIVSD (EVEX Encoded Version) ¶

IF (EVEX.b = 1) AND SRC2 *is a register*
    THEN
        SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(EVEX.RC);
    ELSE
        SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(MXCSR.RC);
FI;
IF k1[0] or *no writemask*
    THEN DEST[63:0] := SRC1[63:0] / SRC2[63:0]
    ELSE
        IF *merging-masking* ; merging-masking
            THEN *DEST[63:0] remains unchanged*
            ELSE ; zeroing-masking
                THEN DEST[63:0] := 0
        FI;
FI;
DEST[127:64] := SRC1[127:64]
DEST[MAXVL-1:128] := 0

VDIVSD (VEX.128 Encoded Version) ¶

DEST[63:0] := SRC1[63:0] / SRC2[63:0]
DEST[127:64] := SRC1[127:64]
DEST[MAXVL-1:128] := 0

DIVSD (128-bit Legacy SSE Version) ¶

DEST[63:0] := DEST[63:0] / SRC[63:0]
DEST[MAXVL-1:64] (Unmodified)

Intel C/C++ Compiler Intrinsic Equivalent ¶

VDIVSD __m128d _mm_mask_div_sd(__m128d s, __mmask8 k, __m128d a, __m128d b);

VDIVSD __m128d _mm_maskz_div_sd( __mmask8 k, __m128d a, __m128d b);

VDIVSD __m128d _mm_div_round_sd( __m128d a, __m128d b, int);

VDIVSD __m128d _mm_mask_div_round_sd(__m128d s, __mmask8 k, __m128d a, __m128d b, int);

VDIVSD __m128d _mm_maskz_div_round_sd( __mmask8 k, __m128d a, __m128d b, int);

DIVSD __m128d _mm_div_sd (__m128d a, __m128d b);

SIMD Floating-Point Exceptions ¶

Overflow, Underflow, Invalid, Divide-by-Zero, Precision, Denormal.

Other Exceptions ¶

VEX-encoded instructions, see Table 2-20, “Type 3 Class Exception Conditions.”

EVEX-encoded instructions, see Table 2-47, “Type E3 Class Exception Conditions.”