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assemblyx86dosx86-16mov

Is there a difference in speed between mov bx,ax and mov bh,ah?

Is there a difference in speed between mov bx,ax and mov bh,ah in a 16-bit MS-DOS application for an 8086 architecture?

Solution

  • If in doubt, profile. But it's very unlikely in this case. From what I gleaned from the Intel 64 and IA32 Architectures Optimization Reference Manual it appears to be that they both perform identically but usually slower than their 32-bit or 64-bit counterparts.