NASM 2.05 based x86 Instruction Reference[ch303]
A.5.279 RSQRTPS: Packed Single-Precision FP Square Root Reciprocal RSQRTPS xmm1,xmm2/m128 ; 0F 52 /r [KATMAI,SSE] RSQRTPS computes the approximate reciprocals of the square roots of the packed single-precision floating-point values in the source and stores the results in xmm1. The maximum error for this approximation is: |Error| <= 1.5 x 2^-12