MULSD (Multiply Scalar Double-Precision Floating-Point Values)

Opcodes

Opcode/Instruction Op/En 64/32-bit Mode CPUID Feature Flag Description
F2 0F 59 /r MULSD xmm1, xmm2/m64 RM V/V SSE2 Multiply the low double-precision floating-point value in xmm2/mem64 by low double-precision floating-point value in xmm1.
VEX.NDS.LIG.F2.0F.WIG 59/r VMULSD xmm1,xmm2, xmm3/m64 RVM V/V AVX Multiply the low double-precision floating-point value in xmm3/mem64 by low double precision floating-point value in xmm2.

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

Multiplies the low double-precision floating-point value in the source operand (second operand) by the low double-precision floating-point value in 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. The high quadword of the destination operand remains unchanged. See Figure 11-4 in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 1, for an illustra-tion of a scalar double-precision floating-point operation.

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

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

VEX.128 encoded version: Bits (VLMAX-1:128) of the destination YMM register are zeroed.

Operation

MULSD (128-bit Legacy SSE version)

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

VMULSD (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

MULSD:

__m128d _mm_mul_sd (m128d a, m128d b)

SIMD Floating-Point Exceptions

Overflow, Underflow, Invalid, Precision, Denormal.

Other Exceptions

See Exceptions Type 3