I've been stuck trying to figure out the addressing mode of this instruction.
Mov dl, byte ptr[bx]
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Peter Cordes
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2I'm not sure what you're asking. What do you think of as the possible "types" of addressing modes? – Nate Eldredge Feb 01 '22 at 18:49
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Related: [Do terms like direct/indirect addressing mode actual exists in the Intel x86 manuals](https://stackoverflow.com/q/46257018) discuses how x86 terminology is used to describe components of x86 addressing modes in the general case, and that it's overrated to worry too much about attaching names to each subset of the general case. – Peter Cordes Feb 02 '22 at 01:35
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That addressing mode is commonly called Register Indirect.
This mov might be described as a load operation — its function is to access memory at the address from the value that is held in the bx register, so it will do:
dl <- Memory [bx]
The size of the memory transfer is 1 byte, while the size of the address is 16-bits (2 bytes) in width.
From a higher-level language perspective, this is a dereference operation — a dereference for read (i.e. a dereference in some other role than the left operand of assignment), for example, as in ... = *p, or ... = p[0].
