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

Syntax

extern __m128i _mm_mask_i64gather_epi64(__m128i def_vals, __int64 const * base, __m128i vindex, __m128i vmask, const int scale);

extern __m256i _mm256_mask_i64gather_epi64(__m128i def_vals, __int64 const * base, __m256i 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 qword 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 using the base address, qword indices and 64-bit scale.

Below is the pseudo-code for the intrinsics:

_mm_mask_i64gather_epi64():

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

_mm256_mask_i64gather_epi64():

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

Returns

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

Para obtener información más completa sobre las optimizaciones del compilador, consulte nuestro Aviso de optimización.