I need a little digital io for my project since cortex-m is not economical for me I need to know can i use Cortex-a to do some embedded jobs?
I hope you don't have too much x86 to convert! I assume you mean straightforward x86, no SIMD, but in any case it is worth looking at converting to C instead and even for SIMD there are intrinsics one can use in C on ARM to do that.
If you are determined to do an assembler conversion there are a number of differences but mostly they are of the known unknowns kind. One particular gotcha on the line of things you may know but it ain't so is how the carry flag works. See Carry flag - Wikipedia, the free encyclopedia for a description of the difference.
See Carry flag - Wikipedia, the free encyclopedia for a description of the difference.
sjdaliyan, the pertinent operation is subtraction.