hsubpd

Horizontal Subtract Packed Double-Precision

HSUBPD xmm1, xmm2/m128

Subtracts adjacent double-precision elements horizontally.

Details

Performs horizontal subtraction of adjacent pairs of double-precision floating-point values in the source and destination XMM registers, storing results in the destination. Specifically, it subtracts the upper element from the lower element of each 128-bit lane (result[63:0] = dest[63:0] - dest[127:64]; result[127:64] = src[63:0] - src[127:64]). All floating-point exception flags may be set based on the operation; no integer flags are affected. This is an SSE3 instruction operating exclusively on 128-bit XMM registers.

Pseudocode Operation

dest[63:0] ← dest[63:0] - dest[127:64];
dest[127:64] ← src[63:0] - src[127:64];

Example

HSUBPD xmm1, xmm2/m128

Encoding

Binary Layout
66
+0
0F
+1
7D
+2
 
Format SSE3
Opcode 66 0F 7D
Extension SSE3

Operands

  • dest
    128-bit XMM SIMD register
  • src
    128-bit XMM SIMD register or Memory operand

Reference (Intel® SDM)

Instruction Forms

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

Description

The HSUBPD instruction subtracts horizontally the packed double precision floating-point 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 quadword 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 3-16 for HSUBPD; see Figure 3-17 for VHSUBPD. HSUBPD xmm1, xmm2/m128 xmm2 [127:64] [63:0] /m128 [127:64] [63:0] xmm1 xmm2/m128[63:0] - Result: xmm1[63:0] - xmm1[127:64] xmm2/m128[127:64] xmm1 [127:64] [63:0] OM15995 Figure 3-16. HSUBPD—Packed Double Precision Floating-Point Horizontal Subtract HSUBPD—Packed Double Precision Floating-Point Horizontal Subtract Vol. 2A 3-442 SRC1 X3 X2 X1 X0 SRC2 Y3 Y2 Y1 Y0 DEST Y2 - Y3 X2 - X3 Y0 - Y1 X0 - X1 Figure 3-17. VHSUBPD operation 128-bit Legacy SSE version: The second source can be an XMM register or an 128-bit memory location. The destination is not distinct from the first source XMM register and the upper bits (MAXVL-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 (MAXVL-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[MAXVL-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[MAXVL-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.

Exceptions

Other Exceptions

See Table 2-19, “Type 2 Class Exception Conditions.” HSUBPD—Packed Double Precision Floating-Point Horizontal Subtract Vol. 2A 3-444

Numeric Exceptions

Overflow, Underflow, Invalid, Precision, Denormal. HSUBPD—Packed Double Precision Floating-Point Horizontal Subtract Vol. 2A 3-443