HSUBPD (Packed Double-FP Horizontal Subtract)

Opcodes

Opcode/Instruction Op/En 64/32-bit Mode CPUID Feature Flag Description
66 0F 7D /r HSUBPD xmm1, xmm2/m128 RM V/V SSE3 Horizontal subtract packed double-precision floating-point values from xmm2/m128 to xmm1.
VEX.NDS.128.66.0F.WIG 7D /r VHSUBPD xmm1,xmm2, xmm3/m128 RVM V/V AVX Horizontal subtract packed double-precision floating-point values from xmm2 and xmm3/mem.
VEX.NDS.256.66.0F.WIG 7D /r VHSUBPD ymm1, ymm2, ymm3/m256 RVM V/V AVX Horizontal subtract packed double-precision floating-point values from ymm2 and ymm3/mem.

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

The HSUBPD instruction subtracts horizontally the packed DP FP numbers of both operands.

Subtracts the double-precision floating-point value in the high quadword of the destination operand from the low quadword of the destination operand and stores the result in the low quadword of the destination operand.

Subtracts the double-precision floating-point value in the high quadword of the source operand from the low quad-word of the source operand and stores the result in the high quadword of the destination operand.

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

See Figure 3-19 for HSUBPD; see Figure 3-20 for VHSUBPD.

Figure 3-19. HSUBPD—Packed Double-FP Horizontal Subtract

X3

X2

X1

X0

SRC1

Y3

Y2

Y1

Y0

SRC2

DEST

Y2 - Y3

X2 - X3

Y0 - Y1

X0 - X1

Figure 3-20. VHSUBPD operation

128-bit Legacy SSE version: The second source can be an XMM register or an 128-bit memory location. The desti-nation is not distinct from the first source XMM register and the upper bits (VLMAX-1:128) of the corresponding YMM register destination are unmodified.

VEX.128 encoded version: the first source operand is an XMM register or 128-bit memory location. The destination operand is an XMM register. The upper bits (VLMAX-1:128) of the corresponding YMM register destination are zeroed.

VEX.256 encoded version: The first source operand is a YMM register. The second source operand can be a YMM register or a 256-bit memory location. The destination operand is a YMM register.

Operation

HSUBPD (128-bit Legacy SSE version)

DEST[63:0] ← SRC1[63:0] - SRC1[127:64]
DEST[127:64] ← SRC2[63:0] - SRC2[127:64]
DEST[VLMAX-1:128] (Unmodified)

VHSUBPD (VEX.128 encoded version)

DEST[63:0] ← SRC1[63:0] - SRC1[127:64]
DEST[127:64] ← SRC2[63:0] - SRC2[127:64]
DEST[VLMAX-1:128] ← 0

VHSUBPD (VEX.256 encoded version)

DEST[63:0] ← SRC1[63:0] - SRC1[127:64]
DEST[127:64] ← SRC2[63:0] - SRC2[127:64]
DEST[191:128] ← SRC1[191:128] - SRC1[255:192]
DEST[255:192] ← SRC2[191:128] - SRC2[255:192]

Intel C/C++ Compiler Intrinsic Equivalent

HSUBPD:

__m128d _mm_hsub_pd(__m128d a, __m128d b)

VHSUBPD:

__m256d _mm256_hsub_pd (__m256d a, __m256d b);

Exceptions

When the source operand is a memory operand, the operand must be aligned on a 16-byte boundary or a general-protection exception (#GP) will be generated.

Numeric Exceptions

Overflow, Underflow, Invalid, Precision, Denormal.

Other Exceptions

See Exceptions Type 2.