[_yosefk]

I always thought the opposite - x86 is perhaps more complicated (though ARM is the most complicated architecture calling itself "RISC" by far, especially the 32b ISA), but x86's emphasis on backward compatibility not only for user code, but for OS/privileged code (where ARM can change completely between revisions) pushes it to have less variability between implementations. In particular I'm almost sure that the memory ops ordering on x86 is more strictly defined with less room for differences between implementations/different execution scenarios given the same instruction stream than ARM. (This however is from hearsay as I never wrote production code for the x86 which depended on this stuff.)