x86doc › SUBSD - Subtract Scalar Double Precision Floating-Point Value

Opcode/Instruction | Op /En | 64/32 bit Mode Support | CPUID Feature Flag | Description |
---|---|---|---|---|

F2 0F 5C /r SUBSD xmm1, xmm2/m64 | A | V/V | SSE2 | Subtract the low double precision floating-point value in xmm2/m64 from xmm1 and store the result in xmm1. |

VEX.LIG.F2.0F.WIG 5C /r VSUBSD xmm1,xmm2, xmm3/m64 | B | V/V | AVX | Subtract the low double precision floating-point value in xmm3/m64 from xmm2 and store the result in xmm1. |

EVEX.LLIG.F2.0F.W1 5C /r VSUBSD xmm1 {k1}{z}, xmm2, xmm3/m64{er} | C | V/V | AVX512F | Subtract the low double precision floating-point value in xmm3/m64 from xmm2 and store the result in xmm1 under writemask k1. |

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 |

Subtract the low double precision floating-point value in the second source operand from the first source operand and stores the double precision floating-point result in the low quadword of the destination operand.

The second source operand can be an XMM register or a 64-bit memory location. The first source and destination operands are XMM registers.

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

VEX.128 and EVEX encoded versions: Bits (127:64) of the XMM register destination are copied from corresponding bits in the first source operand. Bits (MAXVL-1:128) of the destination register are zeroed.

EVEX encoded version: The low quadword element of the destination operand is updated according to the write-mask.

Software should ensure VSUBSD is encoded with VEX.L=0. Encoding VSUBSD with VEX.L=1 may encounter unpre-dictable behavior across different processor generations.

**VSUBSD (EVEX Encoded Version)**

IF (SRC2 *is register*) AND (EVEX.b = 1) 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

**VSUBSD (VEX.128 Encoded Version)**

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

**SUBSD (128-bit Legacy SSE Version)**

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

VSUBSD __m128d _mm_mask_sub_sd (__m128d s, __mmask8 k, __m128d a, __m128d b);

VSUBSD __m128d _mm_maskz_sub_sd (__mmask8 k, __m128d a, __m128d b);

VSUBSD __m128d _mm_sub_round_sd (__m128d a, __m128d b, int);

VSUBSD __m128d _mm_mask_sub_round_sd (__m128d s, __mmask8 k, __m128d a, __m128d b, int);

VSUBSD __m128d _mm_maskz_sub_round_sd (__mmask8 k, __m128d a, __m128d b, int);

SUBSD __m128d _mm_sub_sd (__m128d a, __m128d b);

Overflow, Underflow, Invalid, Precision, Denormal.

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

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