Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 7/13/2023
Public
Document Table of Contents

_mm_mask_i64gather_epi32,_mm256_mask_i64gather_epi32

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

Syntax

extern __m128i _mm_mask_i64gather_epi32(__m128i def_vals, int const * base, __m128i vindex, __m128i vmask, const int scale);

extern __m256i _mm256_mask_i64gather_epi32(__m128i def_vals, int const * base, __m256i vindex, __m128i vmask, const int scale);

Arguments

def_val

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

base

the base address used to reference the loaded dword elements.

vindex

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

vmask

the vector of dword elements used as a vector mask; only the most significant bit of each dword 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 doubleword values from memory using the base address, qword indices and 32-bit scale. The intrinsic _mm_mask_i64gather_epi32() also sets the upper 64-bits of the result to '0'.

Below is the pseudo-code for the intrinsics:

_mm_mask_i64gather_epi32():

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

_mm256_mask_i64gather_epi32():

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

Returns

A 128/256-bit vector with conditionally gathered integer32 values.