Intel 253666-024US User Manual

Page 85

Vol. 2A 3-39

INSTRUCTION SET REFERENCE, A-M

ADDSD—Add Scalar Double-Precision Floating-Point Values

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-preci-
sion floating-point result in the destination operand.
The source operand can be an XMM register or a 64-bit memory location. The desti-
nation operand is an XMM register. The high quadword of the destination operand
remains unchanged. See Chapter 11 in the Intel® 64 and IA-32 Architectures Soft-
ware 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).

Operation

DEST[63:0] ← DEST[63:0]

SRC[63:0];

(* DEST[127:64] unchanged *)

Intel C/C++ Compiler Intrinsic Equivalent

ADDSD

__m128d _mm_add_sd (m128d a, m128d b)

SIMD Floating-Point Exceptions

Overflow, Underflow, Invalid, Precision, Denormal.

Protected Mode Exceptions

#GP(0)

For an illegal memory operand effective address in the CS, DS,

ES, FS or GS segments.

#SS(0)

For an illegal address in the SS segment.

#PF(fault-code)

For a page fault.

#NM

If CR0.TS[bit 3] = 1.

#XM

If an unmasked SIMD floating-point exception and CR4.OSXM-

MEXCPT[bit 10] = 1.

Opcode

Instruction

64-Bit

Mode

Compat/

Leg Mode

Description

F2 0F 58 /r ADDSD xmm1, xmm2/m64 Valid

Valid

Add the low double-

precision floating-point

value from xmm2/m64 to

xmm1.