# _mm256_insertf128_pd

Inserts 128 bits of packed float64 values. The corresponding Intel® AVX instruction is VINSERTF128.

## Syntax

extern __m256d _mm256_insertf128_pd(__m256d a, __m128d b, int offset);

## Arguments

a | 256-bit float64 source vector
b | 128-bit float64 source vector
offset | an integer value that represents the 128-bit offset where the insertion must start

## Description

Performs an insertion of 128 bits of packed double-precision floating-point values (float64 values) from the second source vector b into a destination at a 128-bit offset specified by the offset parameter. The remaining portions of the destination are written by the corresponding elements of the first source vector a.

## Returns

Result of the insertion operation.

Parent topic: Intrinsics for Miscellaneous Operations