pmaddwd

Packed Multiply Add Word to Doubleword (MMX)

PMADDWD mm, mm/m64

Multiplies words and adds adjacent pairs (MMX).

Details

Multiplies four pairs of signed 16-bit words, then adds the high and low results of adjacent pairs to produce two signed 32-bit doublewords. The destination MMX register receives the two packed 32-bit sums. This instruction does not affect any flags and is frequently used in audio/video processing and convolution operations.

Pseudocode Operation

prod[0] ← INT32(dest[0:15]) * INT32(src[0:15]);
prod[1] ← INT32(dest[16:31]) * INT32(src[16:31]);
prod[2] ← INT32(dest[32:47]) * INT32(src[32:47]);
prod[3] ← INT32(dest[48:63]) * INT32(src[48:63]);
dest[0:31] ← prod[0] + prod[1];
dest[32:63] ← prod[2] + prod[3];

Example

PMADDWD mm, mm/m64

Encoding

Binary Layout
0F
+0
F5
+1
 
Format MMX
Opcode NP 0F F5 /r1
Extension MMX

Operands

  • dest
    64-bit MMX register
  • src
    64-bit MMX register or Memory operand

Reference (Intel® SDM)

Instruction Forms

Opcode Instruction Op/En 64/32-bit Mode CPUID Description
NP 0F F5 /r1 PMADDWD mm, mm/m64 A 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 A 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.128.66.0F.WIG F5 /r VPMADDWD xmm1, xmm2, xmm3/m128 B 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.256.66.0F.WIG F5 /r VPMADDWD ymm1, ymm2, ymm3/m256 B 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.
EVEX.128.66.0F.WIG F5 /r VPMADDWD xmm1 {k1}{z}, xmm2, xmm3/m128 C V/V (AVX512VL AND AVX512BW) OR AVX10.1 Multiply the packed word integers in xmm2 by the packed word integers in xmm3/m128, add adjacent doubleword results, and store in xmm1 under writemask k1.
EVEX.256.66.0F.WIG F5 /r VPMADDWD ymm1 {k1}{z}, ymm2, ymm3/m256 C V/V (AVX512VL AND AVX512BW) OR AVX10.1 Multiply the packed word integers in ymm2 by the packed word integers in ymm3/m256, add adjacent doubleword results, and store in ymm1 under writemask k1.
EVEX.512.66.0F.WIG F5 /r VPMADDWD zmm1 {k1}{z}, zmm2, zmm3/m512 C V/V AVX512BW OR AVX10.1 Multiply the packed word integers in zmm2 by the packed word integers in zmm3/m512, add adjacent doubleword results, and store in zmm1 under writemask k1.

Instruction Operand Encoding

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 Full Mem ModRM:reg (w) EVEX.vvvv (r) ModRM:r/m (r) N/A

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 doubleword 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 doubleword 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 4-11 shows this operation when using 64-bit operands). PMADDWD—Multiply and Add Packed Integers Vol. 2B 4-313 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 and not encoded with VEX/EVEX, 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 (MAXVL-1:128) of the corresponding YMM destination 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 (MAXVL-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. EVEX.512 encoded version: The second source operand can be an ZMM register or a 512-bit memory location. The first source and destination operands are ZMM registers. SRC X3 X2 X1 X0 DEST Y3 Y2 Y1 Y0 TEMP X3 ∗ Y3 X2 ∗ Y2 X1 ∗ Y1 X0 ∗ Y0 DEST (X3∗Y3) + (X2∗Y2) (X1∗Y1) + (X0∗Y0) Figure 4-11. 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[MAXVL-1:128] := 0





PMADDWD—Multiply and Add Packed Integers                                                                                                   Vol. 2B 4-314
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])
DEST[MAXVL-1:256] := 0

VPMADDWD (EVEX Encoded Versions)
(KL, VL) = (4, 128), (8, 256), (16, 512)

FOR j := 0 TO KL-1
i := j * 32
IF k1[j] OR *no writemask*
THEN DEST[i+31:i] := (SRC2[i+31:i+16]* SRC1[i+31:i+16]) + (SRC2[i+15:i]*SRC1[i+15:i])
ELSE
IF *merging-masking*                                 ; merging-masking
THEN *DEST[i+31:i] remains unchanged*
ELSE *zeroing-masking*                            ; zeroing-masking
DEST[i+31:i] = 0
FI
FI;
ENDFOR;
DEST[MAXVL-1:VL] := 0

Intel C/C++ Compiler Intrinsic Equivalent

VPMADDWD __m512i _mm512_madd_epi16( __m512i a, __m512i b);
VPMADDWD __m512i _mm512_mask_madd_epi16(__m512i s, __mmask32 k, __m512i a, __m512i b);
VPMADDWD __m512i _mm512_maskz_madd_epi16( __mmask32 k, __m512i a, __m512i b);
VPMADDWD __m256i _mm256_mask_madd_epi16(__m256i s, __mmask16 k, __m256i a, __m256i b);
VPMADDWD __m256i _mm256_maskz_madd_epi16( __mmask16 k, __m256i a, __m256i b);
VPMADDWD __m128i _mm_mask_madd_epi16(__m128i s, __mmask8 k, __m128i a, __m128i b);
VPMADDWD __m128i _mm_maskz_madd_epi16( __mmask8 k, __m128i a, __m128i b);
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.

Exceptions

Other Exceptions

Non-EVEX-encoded instruction, see Table 2-21, “Type 4 Class Exception Conditions.” EVEX-encoded instruction, see Exceptions Type E4NF.nb in Table 2-52, “Type E4NF Class Exception Conditions.” PMADDWD—Multiply and Add Packed Integers Vol. 2B 4-315

Numeric Exceptions

None.