Tree @0.8 (Download .tar.gz)
SixtyPical is a very low-level programming language, similar to 6502 assembly, with static analysis through abstract interpretation.
In practice, this means it catches things like
- you forgot to clear carry before adding something to the accumulator
- a subroutine that you call trashes a register you thought was preserved
- you tried to write the address of something that was not a routine, to a jump vector
and suchlike. It also provides some convenient operations and abstractions based on common machine-language programming idioms, such as
- copying values from one register to another (via a third register when there are no underlying instructions that directly support it)
- explicit tail calls
- indirect subroutine calls
The reference implementation can execute, analyze, and compile SixtyPical programs to 6502 machine code.
It is a work in progress, currently at the proof-of-concept stage.
The current development version of SixtyPical is 0.8.
- Design Goals
- SixtyPical specification
- SixtyPical revision history
- Literate test suite for SixtyPical syntax
- Literate test suite for SixtyPical execution
- Literate test suite for SixtyPical analysis
- Literate test suite for SixtyPical compilation
- 6502 Opcodes used/not used in SixtyPical
Add 16 bit values.
I guess this means making
add a bit more like
And then: add to pointer. (Not necessarily range-checked yet though.)
And then write a little demo "game" where you can move a block around the screen with the joystick.
word table and
vector table types
high address operators
word type into
save registers on stack
This preserves them, so semantically, they can be used even though they are trashed inside the block.
And at some point...
copy x, [ptr] + y
- Maybe even
copy [ptra] + y, [ptrb] + y, which can be compiled to indirect LDA then indirect STA!
- Check that the buffer being read or written to through pointer, appears in approporiate inputs or outputs set.
byte tablememory locations
- always analyze before executing or compiling, unless told not to
- 6502-mnemonic aliases (
- other handy aliases (
copyinstruction able to copy a constant to a user-def mem loc, etc.
- add absolute addressing in shl/shr, absolute-indexed for add, sub, etc.
- check and disallow recursion.
- automatic tail-call optimization (could be tricky, w/constraints?)
- re-order routines and optimize tail-calls to fallthroughs
git clone https://git.catseye.tc/SixtyPical/
- Merge pull request #2 from catseye/develop-0.8 Chris Pressey (commit: GitHub) 2 years ago
- Prep for release of 0.8. Chris Pressey 2 years ago
- A little note on the history. Chris Pressey 2 years ago
- A tiny edit to the TODOs. Chris Pressey 2 years ago
- Deal with the inputs/outputs of buffers, in a weak way. Chris Pressey 2 years ago
- Write stored values, and read values, through pointers. Chris Pressey 2 years ago
- Update documentation. Chris Pressey 2 years ago
- Require that the program does ^buf to get at the address of buf. Chris Pressey 2 years ago
- Introduce IndirectRef and use it instead of adhoc 'copy+y' opcode. Chris Pressey 2 years ago
- Compile copy+y. Chris Pressey 2 years ago