UCOMISD
Usage: UCOMISD src1,src2 Modifies flags: ZF PF CF OF SF AF
Unordered compare of the dbl-prec FP values in the low Qwords of 'src1' operand and 'src2' operand, and sets the ZF, PF, and CF flags in the EFLAGS register to the results the OF, SF and AF flags in the are set to 0.
Unordered Scalar Double-Precision FP compare and set EFLAGS
UCOMISD xmm1,xmm2/m128 ; 66 0F 2E /r [WILLAMETTE,SSE2]
UCOMISD compares the low-order double-precision FP numbers in the two operands, and sets the ZF, PF and CF bits in the EFLAGS register. In addition, the OF, SF and AF bits in the EFLAGS register are zeroed out. The unordered predicate (ZF, PF and CF all set) is returned if either source operand is a NaN (qNaN or sNaN).
EXAMPLE:
ucomisd xmm1 Label