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unwind a day ago

For people not used to reading MC8k assembly [1], it's helpful to point out the basic fact that the syntax is in general

    opcode  source, destination
which is the other way around from most contemporary ISA:s. So a line like

    move.l d0, -(a7)
will first decrement the value of register a7, then write the contents of register d0 to the resulting address (it's a "push" for a downwards-growing stack).

Edit: added Wiki-linkage.

[1]: https://en.wikipedia.org/wiki/Motorola_68000#Instruction_set...

marssaxman 20 hours ago | parent | next [-]

68K style always made more sense to me: we read left-to-right, after all. Why should we suddenly switch directions for the operand order? It's confusing.

a day ago | parent | prev [-]
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