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6809: Allow explicit absolute addressing mode

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This commit is contained in:
Karol Stasiak 2020-07-31 13:26:08 +02:00
parent 33d67ec932
commit ed55e2f081
2 changed files with 4 additions and 0 deletions
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3
docs/lang/assembly6809.md
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@ -48,6 +48,9 @@ To use the direct addressing mode, prepend the argument with `<`:
CLR <$6f // clears the byte $6f in the direct page CLR <$6f // clears the byte $6f in the direct page
CLR $6f // clears the byte $006f (absolute address!) CLR $6f // clears the byte $006f (absolute address!)
You can use `>` do signify the absolute addressing mode, but it is never necessary.
This option exists only for compatibility with other assemblers.
Any assembly opcode can be prefixed with `?`, which allows the optimizer change it or elide it if needed. Any assembly opcode can be prefixed with `?`, which allows the optimizer change it or elide it if needed.
Opcodes without that prefix will be always compiled as written. Opcodes without that prefix will be always compiled as written.

1
src/main/scala/millfork/parser/M6809Parser.scala
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@ -100,6 +100,7 @@ case class M6809Parser(filename: String,
pos <- position() pos <- position()
(a, e) <- (a, e) <-
("#" ~/ HWS ~/ asmExpression).map(Immediate -> _) | ("#" ~/ HWS ~/ asmExpression).map(Immediate -> _) |
(">" ~/ HWS ~/ asmExpression).map(Absolute(false) -> _) |
("<" ~/ HWS ~/ asmExpression).map(DirectPage -> _) | ("<" ~/ HWS ~/ asmExpression).map(DirectPage -> _) |
("[" ~/ AWS ~/ asmParameterNoIndirectOrImmediate ~/ AWS ~/ "]").map { case (a, e) => a.makeIndirect(pos) -> e } | ("[" ~/ AWS ~/ asmParameterNoIndirectOrImmediate ~/ AWS ~/ "]").map { case (a, e) => a.makeIndirect(pos) -> e } |
asmParameterNoIndirectOrImmediate asmParameterNoIndirectOrImmediate