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6 Commits

Author SHA1 Message Date
Andy McFadden
98914e9f80 Treat BRK as a 1-byte instruction
The 65816 definition makes it a two-byte instruction, like COP.  On
the 6502 it acted like a two-byte instruction, but in practice very
few assemblers treat it that way.  Very few humans, for that matter.
So it's now treated as a single byte instruction, with the following
byte encoded as a data value.
2019-08-02 17:21:50 -07:00
Andy McFadden
47b1363738 Add more detail to cross references
In the cross-reference table we now indicate whether the reference
source is doing a read, write, read-modify-write, branch, subroutine
call, is just referencing the address, or is part of the data.
2019-04-11 16:23:02 -07:00
Andy McFadden
a88c746419 Work around cc65 single-pass behavior
The cc65 assembler runs in a single pass, which means forward
address references default to 16 bits.  For zero-page references
we have to add an explicit width disambiguator.  (This is an
unusual situation that only occurs if you have a zero-page .ORG
in the file after code that references it.)

With this change, 2014-label-dp passes, and no other regression
tests were affected.

(issue #40)
2018-11-02 15:32:54 -07:00
Andy McFadden
fd6d8273a9 Add custom flag updaters for ROL/ROR
There are some useful interactions between C/N and maybe Z.  Added
a quick test to 1003-flags-and-branches.

Also, updated the 2008-address-changes tests.  Change b37d3dba
extended the nearby-target range of out-of-file symbols by one, so
one line that didn't get an operand label now does.
2018-10-09 13:15:41 -07:00
Andy McFadden
a23c7e5ab6 Rename undocumented 6502 opcodes to match Unintended Opcodes doc
These *almost* match what cc65 has, and are accepted as primary or
aliases by 64tass.

This combines the LAX and LXA operations.  LXA is the immediate
form of LAX, and behaves somewhat differently (and is unstable).
I was treating them as two separate operations with independent
mnemonics, but that doesn't seem to be the preferred way to
handle it.

The cc65 generator wasn't generating LAX before; now it does.  This
required nudging the width disambiguator, as LAX is a second
example of an instruction with both DP,Y and ABS,Y operands.

(issue #20)
2018-10-05 14:28:45 -07:00
Andy McFadden
2c6212404d Initial file commit 2018-09-28 10:05:11 -07:00