Visible to Intel only — GUID: GUID-EA8089B0-0137-4CDE-9C78-6FE8A45A7346
Visible to Intel only — GUID: GUID-EA8089B0-0137-4CDE-9C78-6FE8A45A7346
<span class='option'>_mm_i64gather_pd, _mm256_i64gather_pd </span>
Gathers 2/4 packed double-precision floating point values from memory referenced by the given base address, qword indices, and scale. The corresponding Intel® AVX2 instruction is VGATHERQPD.
extern __m128d _mm_i64gather_pd(double const * base, __m128i vindex, const int scale); |
extern __m256d _mm256_mask_i64gather_pd(double const * base, __m128i vindex, const int scale); |
base |
the base address used to reference the loaded FP elements. |
vindex |
the vector of qword 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. |
The intrinsics load 2/4 packed double-precision floating-point values from memory using qword indices and updates the destination operand.
Below is the pseudo-code for the intrinsics:
_mm_i64gather_pd():
result[63:0] = mem[base+vindex[63:0]*scale]; result[127:64] = mem[base+vindex[127:64]*scale];
_mm256_i64gather_pd():
result[63:0] = mem[base+vindex[63:0]*scale]; result[127:64] = mem[base+vindex[127:64]*scale]; result[191:128] = mem[base+vindex[191:128]*scale]; result[255:192] = mem[base+vindex[255:192]*scale];
A 128/256-bit vector with unconditionally gathered double-precision FP values.