# _mm256_hadd_pd

Adds horizontal pairs of float64 elements of two vectors. The corresponding Intel® AVX instruction is VHADDPD.

## Syntax

extern __m256d _mm256_hadd_pd(__m256d m1, __m256d m2);

## Arguments

m1 | float64 vector used for the operation
m2 | float64 vector also used for the operation

## Description

Performs a SIMD addition of adjacent (horizontal) pairs of double-precision floating-point elements (float64 elements) ins the first source vector m1 with adjacent pairs of float64 elements in the second source vector m2.

## Returns

Result of the addition operation.

Parent topic: Intrinsics for Arithmetic Operations