_mm_rsqrt14_sd
Classification
AVX-512, Elementary Math Functions, CPUID Test: AVX512F
Header File
Instruction
VRSQRT14SD xmm, xmm, xmm
Synopsis
_mm_rsqrt14_sd(__m128d a, __m128d b);
Description
Compute the approximate reciprocal square root of the lower double-precision (64-bit) floating-point element in "b", store the result in the lower element of "dst", and copy the upper element from "a" to the upper element of "dst". The maximum relative error for this approximation is less than 2^-14.
Operation
dst[63:0] := (1.0 / SQRT(b[63:0]))
dst[127:64] := a[127:64]
dst[MAX:128] := 0