_mm_mask_rsqrt14_pd
Classification
AVX-512, Arithmetic, CPUID Test: AVX512F
Header File
Instruction
VRSQRT14PD xmm {k}, xmm
Synopsis
_mm_mask_rsqrt14_pd(__m128d src, __mmask8 k, __m128d a);
Description
Compute the approximate reciprocal square root of packed double-precision (64-bit) floating-point elements in "a", and store the results in "dst" using writemask "k" (elements are copied from "src" when the corresponding mask bit is not set). The maximum relative error for this approximation is less than 2^-14.
Operation
FOR j := 0 to 1
i := j*64
IF k[j]
dst[i+63:i] := (1.0 / SQRT(a[i+63:i]))
ELSE
dst[i+63:i] := src[i+63:i]
FI
ENDFOR
dst[MAX:128] := 0