PMULHRSW — Packed Multiply High with Round and Scale

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

Description

PMULHRSW multiplies vertically each signed 16-bit integer from the destination operand (first operand) with the corresponding signed 16-bit integer of the source operand (second operand), producing intermediate, signed 32-bit integers. Each intermediate 32-bit integer is truncated to the 18 most significant bits. Rounding is always performed by adding 1 to the least significant bit of the 18-bit intermediate result. The final result is obtained by selecting the 16 bits immediately to the right of the most significant bit of each 18-bit intermediate result and packed to the destination 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.

In 64-bit mode, use the REX prefix to access additional registers.

Legacy SSE version: Both operands can be 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.L must be 0, otherwise the instruction will #UD.

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.

Operation

PMULHRSW (with 64-bit operands)

    temp0[31:0] = INT32 ((DEST[15:0] * SRC[15:0]) >>14) + 1;
    temp1[31:0] = INT32 ((DEST[31:16] * SRC[31:16]) >>14) + 1;
    temp2[31:0] = INT32 ((DEST[47:32] * SRC[47:32]) >> 14) + 1;
    temp3[31:0] = INT32 ((DEST[63:48] * SRc[63:48]) >> 14) + 1;
    DEST[15:0] = temp0[16:1];
    DEST[31:16] = temp1[16:1];
    DEST[47:32] = temp2[16:1];
    DEST[63:48] = temp3[16:1];

PMULHRSW (with 128-bit operand)

    temp0[31:0] = INT32 ((DEST[15:0] * SRC[15:0]) >>14) + 1;
    temp1[31:0] = INT32 ((DEST[31:16] * SRC[31:16]) >>14) + 1;
    temp2[31:0] = INT32 ((DEST[47:32] * SRC[47:32]) >>14) + 1;
    temp3[31:0] = INT32 ((DEST[63:48] * SRC[63:48]) >>14) + 1;
    temp4[31:0] = INT32 ((DEST[79:64] * SRC[79:64]) >>14) + 1;
    temp5[31:0] = INT32 ((DEST[95:80] * SRC[95:80]) >>14) + 1;
    temp6[31:0] = INT32 ((DEST[111:96] * SRC[111:96]) >>14) + 1;
    temp7[31:0] = INT32 ((DEST[127:112] * SRC[127:112) >>14) + 1;
    DEST[15:0] = temp0[16:1];
    DEST[31:16] = temp1[16:1];
    DEST[47:32] = temp2[16:1];
    DEST[63:48] = temp3[16:1];
    DEST[79:64] = temp4[16:1];
    DEST[95:80] = temp5[16:1];
    DEST[111:96] = temp6[16:1];
    DEST[127:112] = temp7[16:1];

VPMULHRSW (VEX.128 encoded version)

temp0[31:0] ← INT32 ((SRC1[15:0] * SRC2[15:0]) >>14) + 1
temp1[31:0] ← INT32 ((SRC1[31:16] * SRC2[31:16]) >>14) + 1
temp2[31:0] ← INT32 ((SRC1[47:32] * SRC2[47:32]) >>14) + 1
temp3[31:0] ← INT32 ((SRC1[63:48] * SRC2[63:48]) >>14) + 1
temp4[31:0] ← INT32 ((SRC1[79:64] * SRC2[79:64]) >>14) + 1
temp5[31:0] ← INT32 ((SRC1[95:80] * SRC2[95:80]) >>14) + 1
temp6[31:0] ← INT32 ((SRC1[111:96] * SRC2[111:96]) >>14) + 1
temp7[31:0] ← INT32 ((SRC1[127:112] * SRC2[127:112) >>14) + 1
DEST[15:0] ← temp0[16:1]
DEST[31:16] ← temp1[16:1]
DEST[47:32] ← temp2[16:1]
DEST[63:48] ← temp3[16:1]
DEST[79:64] ← temp4[16:1]
DEST[95:80] ← temp5[16:1]
DEST[111:96] ← temp6[16:1]
DEST[127:112] ← temp7[16:1]
DEST[VLMAX-1:128] ← 0

VPMULHRSW (VEX.256 encoded version)

temp0[31:0] ← INT32 ((SRC1[15:0] * SRC2[15:0]) >>14) + 1
temp1[31:0] ← INT32 ((SRC1[31:16] * SRC2[31:16]) >>14) + 1
temp2[31:0] ← INT32 ((SRC1[47:32] * SRC2[47:32]) >>14) + 1
temp3[31:0] ← INT32 ((SRC1[63:48] * SRC2[63:48]) >>14) + 1
temp4[31:0] ← INT32 ((SRC1[79:64] * SRC2[79:64]) >>14) + 1
temp5[31:0] ← INT32 ((SRC1[95:80] * SRC2[95:80]) >>14) + 1
temp6[31:0] ← INT32 ((SRC1[111:96] * SRC2[111:96]) >>14) + 1
temp7[31:0] ← INT32 ((SRC1[127:112] * SRC2[127:112) >>14) + 1
temp8[31:0] ← INT32 ((SRC1[143:128] * SRC2[143:128]) >>14) + 1
temp9[31:0] ← INT32 ((SRC1[159:144] * SRC2[159:144]) >>14) + 1
temp10[31:0] ← INT32 ((SRC1[75:160] * SRC2[175:160]) >>14) + 1
temp11[31:0] ← INT32 ((SRC1[191:176] * SRC2[191:176]) >>14) + 1
temp12[31:0] ← INT32 ((SRC1[207:192] * SRC2[207:192]) >>14) + 1
temp13[31:0] ← INT32 ((SRC1[223:208] * SRC2[223:208]) >>14) + 1
temp14[31:0] ← INT32 ((SRC1[239:224] * SRC2[239:224]) >>14) + 1
temp15[31:0] ← INT32 ((SRC1[255:240] * SRC2[255:240) >>14) + 1

Intel C/C++ Compiler Intrinsic Equivalents

PMULHRSW:

__m64 _mm_mulhrs_pi16 (__m64 a, __m64 b)

(V)PMULHRSW:

__m128i _mm_mulhrs_epi16 (__m128i a, __m128i b)

VPMULHRSW:

__m256i _mm256_mulhrs_epi16 (__m256i a, __m256i b)

SIMD Floating-Point Exceptions

None.

Other Exceptions

See Exceptions Type 4; additionally