Comment by dzaima

Have to be rather careful with such - e.g. an x86 vaddpd or an ARM fadd aren't commutative because of NaN bit patterns (even worse for fma, esp. if you have it automatically choose the operation from which arg it's destructive over).

Perhaps not significant for writing code (though maybe someone does want the NaN bit pattern to be taken from a specific arg!), but is one aspect that can easily go missing in a higher-level assembler (or esp. disassembler).