having read the intel manual I understand that comisd instruction results in bits being set in the eflags register. However I do not uinderstand how to check the eflags register as for unordered arguments to comisd all relevant flags are set and for ordered comparisons individual relevant flags are set. Could someone please give some code as examples of the use of comisd and the checking of the eflags register.
comisd XMM1, XMM2
;Code here for equal, or a jmp, or a jz.
If I recall correctly, you can just use ja and jb. For some reason they decided not to use jg and jl. All other should work as expected.