Developer Guide and Reference

Contents

_mm_i32gather_ps, _mm256_i32gather_ps

Gathers 2/4 packed single-precision floating point values from memory referenced by the given base address, dword indices, and scale. The corresponding Intel® AVX2 instruction is
VGATHERDPS
.

Syntax

extern __m128 _mm_mask_i32gather_ps(float const * base, __m128i vindex, const int scale);
extern __m256 _mm256_mask_i32gather_ps(float const * base, __m256i vindex, const int scale);
Arguments
base
the base address used to reference the loaded FP elements.
vindex
the vector of dword indices used to reference the loaded FP 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 packed single-precision floating-point values from memory using dword indices.
Below is the pseudo-code for the intrinsics:
_mm_i32gather_ps()
:
result[31:0] = mem[base+vindex[31:0]*scale]; result[63:32] = mem[base+vindex[63:32]*scale]; result[95:64] = mem[base+vindex[95:64]*scale]; result127:96] = mem[base+vindex[127:96]*scale];
_mm256_i32gather_ps()
:
result[31:0] = mem[base+vindex[31:0]*scale]; result[63:32] = mem[base+vindex[63:32]*scale]; result[95:64] = mem[base+vindex[95:64]*scale]; result127:96] = mem[base+vindex[127:96]*scale]; result[159:128] = mem[base+vindex[159:128]*scale]; result[191:160] = mem[base+vindex[191:160]*scale]; result[223:192] = mem[base+vindex[223:192]*scale]; result[255:224] = mem[base+vindex[255:224]*scale];
Returns
A 128/256-bit vector with unconditionally gathered single-precision FP values.