NASM 2.05 based x86 Instruction Reference[ch176]
A.5.154 MINSD: Return Scalar Double-Precision FP Minimum MINSD xmm1,xmm2/m64 ; F2 0F 5D /r [WILLAMETTE,SSE2] MINSD compares the low-order double-precision FP numbers from xmm1 and xmm2/mem, and stores the minimum value in xmm1. If the values being compared are both zeroes, source2 (xmm2/m64) would be returned. If source2 (xmm2/m64) is an SNaN, this SNaN is forwarded unchanged to the destination (i.e., a QNaN version of the SNaN is not returned). The high quadword of the destination is left unchanged.