PMADDWD—Multiply and Add Packed Integers

Opcode/Instruction	Op/En	64/32 bit Mode Support	CPUID Feature Flag	Description
0F F5 /r¹ PMADDWD mm, mm/m64	RM	V/V	MMX	Multiply the packed words in mm by the packed words in mm/m64, add adjacent doubleword results, and store in mm.
66 0F F5 /r PMADDWD xmm1, xmm2/m128	RM	V/V	SSE2	Multiply the packed word integers in xmm1 by the packed word integers in xmm2/m128, add adjacent doubleword results, and store in xmm1.
VEX.NDS.128.66.0F.WIG F5 /r VPMADDWD xmm1, xmm2, xmm3/m128	RVM	V/V	AVX	Multiply the packed word integers in xmm2 by the packed word integers in xmm3/m128, add adjacent doubleword results, and store in xmm1.
VEX.NDS.256.66.0F.WIG F5 /r VPMADDWD ymm1, ymm2, ymm3/m256	RVM	V/V	AVX2	Multiply the packed word integers in ymm2 by the packed word integers in ymm3/m256, add adjacent doubleword results, and store in ymm1.

NOTES:

1. See note in Section 2.4, “Instruction Exception Specification” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A and Section 22.25.3, “Exception Conditions of Legacy SIMD Instructions Operating on MMX Registers” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A.

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 individual signed words of the destination operand (first operand) by the corresponding signed words of the source operand (second operand), producing temporary signed, doubleword results. The adjacent double-word results are then summed and stored in the destination operand. For example, the corresponding low-order words (15-0) and (31-16) in the source and destination operands are multiplied by one another and the double-word results are added together and stored in the low doubleword of the destination register (31-0). The same operation is performed on the other pairs of adjacent words. (Figure 4-7 shows this operation when using 64-bit operands).

The (V)PMADDWD instruction wraps around only in one situation: when the 2 pairs of words being operated on in a group are all 8000H. In this case, the result wraps around to 80000000H.

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

Legacy SSE version: The first source and destination operands are MMX registers. The second source operand is an MMX register or a 64-bit memory location.

128-bit Legacy SSE version: The first source and destination operands are XMM registers. The second source operand is an XMM register or a 128-bit memory location. Bits (VLMAX-1:128) of the corresponding YMM destina-tion register remain unchanged.

VEX.128 encoded version: The first source and destination operands are XMM registers. The second source operand is an XMM register or a 128-bit memory location. Bits (VLMAX-1:128) of the destination YMM register are zeroed.

VEX.256 encoded version: The second source operand can be an YMM register or a 256-bit memory location. The first source and destination operands are YMM registers.

Note: VEX.L must be 0, otherwise the instruction will #UD.

Figure 4-7. PMADDWD Execution Model Using 64-bit Operands

Operation

PMADDWD (with 64-bit operands)

    DEST[31:0] ← (DEST[15:0] ∗ SRC[15:0]) + (DEST[31:16] ∗ SRC[31:16]);
    DEST[63:32] ← (DEST[47:32] ∗ SRC[47:32]) + (DEST[63:48] ∗ SRC[63:48]);

PMADDWD (with 128-bit operands)

    DEST[31:0] ← (DEST[15:0] ∗ SRC[15:0]) + (DEST[31:16] ∗ SRC[31:16]);
    DEST[63:32] ← (DEST[47:32] ∗ SRC[47:32]) + (DEST[63:48] ∗ SRC[63:48]);
    DEST[95:64] ← (DEST[79:64] ∗ SRC[79:64]) + (DEST[95:80] ∗ SRC[95:80]);
    DEST[127:96] ← (DEST[111:96] ∗ SRC[111:96]) + (DEST[127:112] ∗ SRC[127:112]);

VPMADDWD (VEX.128 encoded version)

DEST[31:0] ← (SRC1[15:0] * SRC2[15:0]) + (SRC1[31:16] * SRC2[31:16])
DEST[63:32] ← (SRC1[47:32] * SRC2[47:32]) + (SRC1[63:48] * SRC2[63:48])
DEST[95:64] ← (SRC1[79:64] * SRC2[79:64]) + (SRC1[95:80] * SRC2[95:80])
DEST[127:96] ← (SRC1[111:96] * SRC2[111:96]) + (SRC1[127:112] * SRC2[127:112])
DEST[VLMAX-1:128] ← 0

VPMADDWD (VEX.256 encoded version)

DEST[31:0] ← (SRC1[15:0] * SRC2[15:0]) + (SRC1[31:16] * SRC2[31:16])
DEST[63:32] ← (SRC1[47:32] * SRC2[47:32]) + (SRC1[63:48] * SRC2[63:48])
DEST[95:64] ← (SRC1[79:64] * SRC2[79:64]) + (SRC1[95:80] * SRC2[95:80])
DEST[127:96] ← (SRC1[111:96] * SRC2[111:96]) + (SRC1[127:112] * SRC2[127:112])
DEST[159:128] ← (SRC1[143:128] * SRC2[143:128]) + (SRC1[159:144] * SRC2[159:144])
DEST[191:160] ← (SRC1[175:160] * SRC2[175:160]) + (SRC1[191:176] * SRC2[191:176])
DEST[223:192] ← (SRC1[207:192] * SRC2[207:192]) + (SRC1[223:208] * SRC2[223:208])
DEST[255:224] ← (SRC1[239:224] * SRC2[239:224]) + (SRC1[255:240] * SRC2[255:240])

Intel C/C++ Compiler Intrinsic Equivalent

PMADDWD:

__m64 _mm_madd_pi16(__m64 m1, __m64 m2)

(V)PMADDWD:

__m128i _mm_madd_epi16 ( __m128i a, __m128i b)

VPMADDWD:

__m256i _mm256_madd_epi16 ( __m256i a, __m256i b)

Flags Affected

None.

Numeric Exceptions

None.

Other Exceptions

See Exceptions Type 4; additionally

#UD	If VEX.L = 1.