The decision of how to handle indeterminate M/X flag values is made in
StatusFlags. This provides consistent behavior throughout the app.
This was being done for M/X but not for E.
This change also renames the M/X tests, prefixing them with "Is" to
emphasize that they are boolean rather than tri-state.
There should be no change in behavior from this.
The "affected flags" constants were incorrect for BIT, BRK, COP,
RTI, XCE, and the undocmented instructions ANE, DCP, and SAX. The
constants are used for the changed-flag summary shown in the info
window and the instruction chart.
Of greater import: the status flag updater for BIT was incorrectly
marking N/V/C as indeterminate instead of N/V/Z. The undocmented
instructions ANE, DCP, and SAX were also incorrect.
The cycle counts shown in line comments are computed correctly, but
the counts shown in the info window and instruction chart were
displaying the full set of modifiers, ignoring the CPU type. That's
okay for the info window, which spells the modifiers out, though
it'd be better if the bits were explicitly marked as being applicable
to the current CPU or a different one.
This adds a window that displays all of the instructions for a
given CPU in a summary grid. Undocumented instructions are
included, but shown in grey italics.
Also, tweaked AppSettings to not mark itself as dirty if a "set"
operation doesn't actually change anything.
Early data sheets listed BRK as one byte, but RTI after a BRK skips
the following byte, effectively making BRK a 2-byte instruction.
Sometimes, such as when diassembling Apple /// SOS code, it's handy
to treat it that way explicitly.
This change makes two-byte BRKs optional, controlled by a checkbox
in the project settings. In the system definitions it defaults to
true for Apple ///, false for all others.
ACME doesn't allow BRK to have an arg, and cc65 only allows it for
65816 code (?), so it's emitted as a hex blob for those assemblers.
Anyone wishing to target those assemblers should stick to 1-byte mode.
Extension scripts have to switch between formatting one byte of
inline data and formatting an instruction with a one-byte operand.
A helper function has been added to the plugin Util class.
To get some regression test coverage, 2022-extension-scripts has
been configured to use two-byte BRK.
Also, added/corrected some SOS constants.
See also issue #44.
In a recent survey, three out of four cross assemblers surveyed
recommended not using opcode mnemonics to their patients who use
labels. We now remap labels like "AND" and "jmp", using the label
map that's part of the label localizer.
We skip the step for Merlin 32, which is perfectly happy to assemble
"JMP JMP JMP".
Also, fixed a bug in MaskLeadingUnderscores that could hang the
source generator thread.
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.
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)
