ADDSD (Add Scalar Double-Precision Floating-Point Values)

Opcodes

Opcode/Instruction Op/En 64/32-bit Mode CPUID Feature Flag Description
F2 0F 58 /r ADDSD xmm1, xmm2/m64 RM V/V SSE2 Add the low double-precision floating-point value from xmm2/m64 to xmm1.
VEX.NDS.LIG.F2.0F.WIG 58 /r VADDSD xmm1, xmm2, xmm3/m64 RVM V/V AVX Add the low double-precision floating-point value from xmm3/mem to xmm2 and store the result in xmm1.

Instruction Operand Encoding

Op/En Operand 1 Operand 2 Operand 3 Operand 4
RM ModRM:reg (r, w) ModRM:r/m (r) NA NA
RVM ModRM:reg (w) VEX.vvvv (r) ModRM:r/m (r)) NA

Description

Adds the low double-precision floating-point values from the source operand (second operand) and the destination operand (first operand), and stores the double-precision floating-point result in the destination operand.

The source operand can be an XMM register or a 64-bit memory location. The destination operand is an XMM register. See Chapter 11 in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 1, for an overview of a scalar double-precision floating-point operation.

In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to access additional registers (XMM8-XMM15).

128-bit Legacy SSE version: Bits (VLMAX-1:64) of the corresponding YMM destination register remain unchanged.

VEX.128 encoded version: Bits (127:64) of the XMM register destination are copied from corresponding bits in the first source operand. Bits (VLMAX-1:128) of the destination YMM register are zeroed.

Operation

ADDSD (128-bit Legacy SSE version)

DEST[63:0] ← DEST[63:0] + SRC[63:0]
DEST[VLMAX-1:64] (Unmodified)

VADDSD (VEX.128 encoded version)

DEST[63:0] ← SRC1[63:0] + SRC2[63:0]
DEST[127:64] ← SRC1[127:64]
DEST[VLMAX-1:128] ← 0

Intel C/C++ Compiler Intrinsic Equivalent

ADDSD:

__m128d _mm_add_sd (m128d a, m128d b)

SIMD Floating-Point Exceptions

Overflow, Underflow, Invalid, Precision, Denormal.

Other Exceptions

See Exceptions Type 3.