_mm_mask_rsqrt28_ss
Classification
AVX-512, Elementary Math Functions, CPUID Test: AVX512ER
Header File
Instruction
VRSQRT28SS xmm {k}, xmm, xmm
Synopsis
_mm_mask_rsqrt28_ss(__m128 src, __mmask8 k, __m128 a, __m128 b);
Description
Compute the approximate reciprocal square root of the lower single-precision (32-bit) floating-point element in "b", store the result in the lower element of "dst" using writemask "k" (the element is copied from "src" when mask bit 0 is not set), and copy the upper 3 packed elements from "a" to the upper elements of "dst". The maximum relative error for this approximation is less than 2^-28.
Operation
IF k[0]
dst[31:0] := (1.0 / SQRT(b[31:0]))
ELSE
dst[31:0] := src[31:0]
FI
dst[127:32] := a[127:32]
dst[MAX:128] := 0