Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

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_mm_mask_i32gather_epi64,_mm256_mask_i32gather_epi64

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

Syntax

extern __m128i _mm_mask_i32gather_epi64(__m128i def_vals, __int64 const * base, __m128i vindex, __m128i vmask, const int scale);

extern __m256i _mm256_mask_i32gather_epi64(__m256i def_vals, __int64 const * base, __m128i vindex, __m256i vmask, const int scale);

Arguments

def_val

the vector of qword values copied to the destination when the corresponding element of the vector mask is '0'.

base

the base address used to reference the loaded qword elements.

vindex

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

vmask

the vector of qword elements used as a vector mask; only the most significant bit of each qword is used as a mask.

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 conditionally load 2/4 quadword values from memory referenced by the given base address, dword indices and scale, and using the given qword mask values.

Below is the pseudo-code for the intrinsics:

_mm_mask_i32gather_epi64():

result[63:0] = (vmask[63]==1) ? (mem[base+vindex[31:0]*scale]) : (def_vals[63:0]);
result[127:64] = (vmask[127]==1) ? (mem[base+vindex[63:32]*scale]) : (def_vals[127:64]);

_mm256_mask_i32gather_epi64():

result[63:0] = (vmask[63]==1) ? (mem[base+vindex[31:0]*scale]) : (def_vals[63:0]);
result[127:64] = (vmask[127]==1) ? (mem[base+vindex[63:32]*scale]) : (def_vals[127:64]);
result[191:128] = (vmask[191]==1) ? (mem[base+vindex[95:64]*scale]) : (def_vals[191:128]);
result[255:192] = (vmask[255]==1) ? (mem[base+vindex[127:96]*scale]) : (def_vals[255:192]);
Returns

A 256/128-bit vector with conditionally gathered interger64 values.