PHADDW/PHADDD — Packed Horizontal Add
| Opcode/Instruction | Op/En | 64/32 bit Mode Support | CPUID Feature Flag | Description |
|---|---|---|---|---|
| NP 0F 38 01 /r1 PHADDW mm1, mm2/m64 | RM | V/V | SSSE3 | Add 16-bit integers horizontally, pack to mm1. |
| 66 0F 38 01 /r PHADDW xmm1, xmm2/m128 | RM | V/V | SSSE3 | Add 16-bit integers horizontally, pack to xmm1. |
| NP 0F 38 02 /r PHADDD mm1, mm2/m64 | RM | V/V | SSSE3 | Add 32-bit integers horizontally, pack to mm1. |
| 66 0F 38 02 /r PHADDD xmm1, xmm2/m128 | RM | V/V | SSSE3 | Add 32-bit integers horizontally, pack to xmm1. |
| VEX.128.66.0F38.WIG 01 /r VPHADDW xmm1, xmm2, xmm3/m128 | RVM | V/V | AVX | Add 16-bit integers horizontally, pack to xmm1. |
| VEX.128.66.0F38.WIG 02 /r VPHADDD xmm1, xmm2, xmm3/m128 | RVM | V/V | AVX | Add 32-bit integers horizontally, pack to xmm1. |
| VEX.256.66.0F38.WIG 01 /r VPHADDW ymm1, ymm2, ymm3/m256 | RVM | V/V | AVX2 | Add 16-bit signed integers horizontally, pack to ymm1. |
| VEX.256.66.0F38.WIG 02 /r VPHADDD ymm1, ymm2, ymm3/m256 | RVM | V/V | AVX2 | Add 32-bit signed integers horizontally, pack to ymm1. |
1. See note in Section 2.5, “Intel® AVX and Intel® SSE Instruction Exception Classification,” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A, and Section 23.25.3, “Exception Conditions of Legacy SIMD Instructions Operating on MMX Registers,” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3B.
Instruction Operand Encoding ¶
| Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
|---|---|---|---|---|
| RM | ModRM:reg (r, w) | ModRM:r/m (r) | N/A | N/A |
| RVM | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | N/A |
Description ¶
(V)PHADDW adds two adjacent 16-bit signed integers horizontally from the source and destination operands and packs the 16-bit signed results to the destination operand (first operand). (V)PHADDD adds two adjacent 32-bit signed integers horizontally from the source and destination operands and packs the 32-bit signed results to the destination operand (first operand). When the source operand is a 128-bit memory operand, the operand must be aligned on a 16-byte boundary or a general-protection exception (#GP) will be generated.
Note that these instructions can operate on either unsigned or signed (two’s complement notation) integers; however, it does not set bits in the EFLAGS register to indicate overflow and/or a carry. To prevent undetected overflow conditions, software must control the ranges of the values operated on.
Legacy SSE instructions: Both operands can be MMX registers. The second source operand can be 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 can be an XMM register or a 128-bit memory location. Bits (MAXVL-1:128) of the corresponding YMM destination register remain unchanged.
In 64-bit mode, use the REX prefix to access additional registers.
VEX.128 encoded version: The first source and destination operands are XMM registers. The second source operand can be an XMM register or a 128-bit memory location. Bits (MAXVL-1:128) of the corresponding YMM register are zeroed.
VEX.256 encoded version: Horizontal addition of two adjacent data elements of the low 16-bytes of the first and second source operands are packed into the low 16-bytes of the destination operand. Horizontal addition of two adjacent data elements of the high 16-bytes of the first and second source operands are packed into the high 16-bytes of the destination operand. The first source and destination operands are YMM registers. The second source operand can be an YMM register or a 256-bit memory location.
S7 S3 S3 S4 S3 S2 S1 S0
Operation ¶
PHADDW (With 64-bit Operands) ¶
mm1[15-0] = mm1[31-16] + mm1[15-0]; mm1[31-16] = mm1[63-48] + mm1[47-32]; mm1[47-32] = mm2/m64[31-16] + mm2/m64[15-0]; mm1[63-48] = mm2/m64[63-48] + mm2/m64[47-32];
PHADDW (With 128-bit Operands) ¶
xmm1[15-0] = xmm1[31-16] + xmm1[15-0]; xmm1[31-16] = xmm1[63-48] + xmm1[47-32]; xmm1[47-32] = xmm1[95-80] + xmm1[79-64]; xmm1[63-48] = xmm1[127-112] + xmm1[111-96]; xmm1[79-64] = xmm2/m128[31-16] + xmm2/m128[15-0]; xmm1[95-80] = xmm2/m128[63-48] + xmm2/m128[47-32]; xmm1[111-96] = xmm2/m128[95-80] + xmm2/m128[79-64]; xmm1[127-112] = xmm2/m128[127-112] + xmm2/m128[111-96];
VPHADDW (VEX.128 Encoded Version) ¶
DEST[15:0] := SRC1[31:16] + SRC1[15:0] DEST[31:16] := SRC1[63:48] + SRC1[47:32] DEST[47:32] := SRC1[95:80] + SRC1[79:64] DEST[63:48] := SRC1[127:112] + SRC1[111:96] DEST[79:64] := SRC2[31:16] + SRC2[15:0] DEST[95:80] := SRC2[63:48] + SRC2[47:32] DEST[111:96] := SRC2[95:80] + SRC2[79:64] DEST[127:112] := SRC2[127:112] + SRC2[111:96] DEST[MAXVL-1:128] := 0
VPHADDW (VEX.256 Encoded Version) ¶
DEST[15:0] := SRC1[31:16] + SRC1[15:0] DEST[31:16] := SRC1[63:48] + SRC1[47:32] DEST[47:32] := SRC1[95:80] + SRC1[79:64] DEST[63:48] := SRC1[127:112] + SRC1[111:96] DEST[79:64] := SRC2[31:16] + SRC2[15:0] DEST[95:80] := SRC2[63:48] + SRC2[47:32] DEST[111:96] := SRC2[95:80] + SRC2[79:64] DEST[127:112] := SRC2[127:112] + SRC2[111:96] DEST[143:128] := SRC1[159:144] + SRC1[143:128] DEST[159:144] := SRC1[191:176] + SRC1[175:160] DEST[175:160] := SRC1[223:208] + SRC1[207:192] DEST[191:176] := SRC1[255:240] + SRC1[239:224] DEST[207:192] := SRC2[127:112] + SRC2[143:128] DEST[223:208] := SRC2[159:144] + SRC2[175:160] DEST[239:224] := SRC2[191:176] + SRC2[207:192] DEST[255:240] := SRC2[223:208] + SRC2[239:224]
PHADDD (With 64-bit Operands) ¶
mm1[31-0] = mm1[63-32] + mm1[31-0]; mm1[63-32] = mm2/m64[63-32] + mm2/m64[31-0];
PHADDD (With 128-bit Operands) ¶
xmm1[31-0] = xmm1[63-32] + xmm1[31-0]; xmm1[63-32] = xmm1[127-96] + xmm1[95-64]; xmm1[95-64] = xmm2/m128[63-32] + xmm2/m128[31-0]; xmm1[127-96] = xmm2/m128[127-96] + xmm2/m128[95-64];
VPHADDD (VEX.128 Encoded Version) ¶
DEST[31-0] := SRC1[63-32] + SRC1[31-0] DEST[63-32] := SRC1[127-96] + SRC1[95-64] DEST[95-64] := SRC2[63-32] + SRC2[31-0] DEST[127-96] := SRC2[127-96] + SRC2[95-64] DEST[MAXVL-1:128] := 0
VPHADDD (VEX.256 Encoded Version) ¶
DEST[31-0] := SRC1[63-32] + SRC1[31-0] DEST[63-32] := SRC1[127-96] + SRC1[95-64] DEST[95-64] := SRC2[63-32] + SRC2[31-0] DEST[127-96] := SRC2[127-96] + SRC2[95-64] DEST[159-128] := SRC1[191-160] + SRC1[159-128] DEST[191-160] := SRC1[255-224] + SRC1[223-192] DEST[223-192] := SRC2[191-160] + SRC2[159-128] DEST[255-224] := SRC2[255-224] + SRC2[223-192]
Intel C/C++ Compiler Intrinsic Equivalents ¶
PHADDW __m64 _mm_hadd_pi16 (__m64 a, __m64 b)
PHADDD __m64 _mm_hadd_pi32 (__m64 a, __m64 b)
(V)PHADDW __m128i _mm_hadd_epi16 (__m128i a, __m128i b)
(V)PHADDD __m128i _mm_hadd_epi32 (__m128i a, __m128i b)
VPHADDW __m256i _mm256_hadd_epi16 (__m256i a, __m256i b)
VPHADDD __m256i _mm256_hadd_epi32 (__m256i a, __m256i b)
SIMD Floating-Point Exceptions ¶
None.
Other Exceptions ¶
See Table 2-21, “Type 4 Class Exception Conditions,” additionally:
| #UD | If VEX.L = 1. |