Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 3/31/2023
Public

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_mm_i32gather_epi64,_mm256_i32gather_epi64

Gathers 2/4 quadword values from memory referenced by the given base address, dword indices and scale. The corresponding Intel® AVX2 instruction is VPGATHERDQ.

Syntax

extern __m128i _mm_i32gather_epi64(__int64 const * base, __m128i vindex, const int scale);

extern __m256i _mm256_i32gather_epi64(__int64 const * base, __m128i vindex, const int scale);

Arguments

base

the base address used to reference the loaded qword elements.

vindex

the vector of dword indices used to reference the loaded qword elements.

scale

The compilation time literal constant, which is used as the vector indices scale to address the loaded elements. Possible values are one of the following: 1, 2, 4, 8.

Description

The intrinsics load 2/4 quadword values from memory using the base address, dword indices, and 64-bit scale.

Below is the pseudo-code for the intrinsics:

_mm_i32gather_epi64():

result[63:0] = mem[base+vindex[31:0]*scale];
result[127:64] = mem[base+vindex[63:32]*scale];

_mm256_i32gather_epi64():

result[63:0] = mem[base+vindex[31:0]*scale];
result[127:64] = mem[base+vindex[63:32]*scale];
result[191:128] = mem[base+vindex[95:64]*scale];
result[255:192] = mem[base+vindex[127:96]*scale];

Returns

A 128/256-bit vector with unconditionally gathered integer64 values.