mirror of
https://github.com/irmen/prog8.git
synced 2024-11-20 03:32:05 +00:00
2d34fdd28f
this fixes some obscure assembly issues where subroutines were omitted from the output program by 64tass
100 lines
7.2 KiB
ReStructuredText
100 lines
7.2 KiB
ReStructuredText
TODO
|
|
====
|
|
|
|
For next release
|
|
^^^^^^^^^^^^^^^^
|
|
...
|
|
|
|
|
|
Need help with
|
|
^^^^^^^^^^^^^^
|
|
- c128 target: various machine specific things (free zp locations, how banking works, getting the floating point routines working, ...)
|
|
- atari target: more details details about the machine, fixing library routines. I have no clue whatsoever.
|
|
- see the :ref:`portingguide` for details on what information is needed.
|
|
|
|
|
|
Future Things and Ideas
|
|
^^^^^^^^^^^^^^^^^^^^^^^
|
|
Compiler:
|
|
- vm: implement remaining sin/cos functions in math.p8 and merge tables
|
|
- vm: implement memory mapped variables properly in VariableAllocator
|
|
- vm: find a solution for the cx16.r0..r15 that "overlap" (r0, r0L, r0H etc) but in the vm each get their own separate variable location now. Maybe this gets solved by the previous item?
|
|
- vm: encode romsub & romsub call in VM IR (can just crash in virtualmachine itself because program is not in the simulated memory) ExpressionGen.kt
|
|
- vm: how to remove all unused subroutines? (the 6502 assembly codegen relies on 64tass solve this for us)
|
|
- vm: rather than being able to jump to any 'address' (IPTR), use 'blocks' that have entry and exit points -> even better dead code elimination possible too
|
|
- vm: add more optimizations in VmPeepholeOptimizer
|
|
- see if we can let for loops skip the loop if end<start, like other programming languages. Without adding a lot of code size/duplicating the loop condition.
|
|
this is documented behavior to now loop around but it's too easy to forget about!
|
|
Lot of work because of so many special cases in ForLoopsAsmgen.....
|
|
How is it for the vm target? -> just 2 special cases in CodeGen.
|
|
- when the vm is stable and *if* its language can get promoted to prog8 IL, the variable allocation should be changed.
|
|
It's now done before the vm code generation, but the IL should probably not depend on the allocations already performed.
|
|
So the CodeGen doesn't do VariableAlloc *before* the codegen, but as a last step instead.
|
|
- createAssemblyAndAssemble(): make it possible to actually get rid of the VarDecl nodes by fixing the rest of the code mentioned there.
|
|
but probably better to rewrite the 6502 codegen on top of the new Ast.
|
|
- generate WASM from the new ast (or from vm code?) to eventually run prog8 on a browser canvas?
|
|
- make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as ``p8v_``? Or not worth it (most 3 letter opcodes as variables are nonsensical anyway)
|
|
then we can get rid of the instruction lists in the machinedefinitions as well?
|
|
- [problematic due to using 64tass:] add a compiler option to not remove unused subroutines. this allows for building library programs. But this won't work with 64tass's .proc ...
|
|
Perhaps replace all uses of .proc/.pend by .block/.bend will fix that with a compiler flag?
|
|
But all library code written in asm uses .proc already..... (search/replace when writing the actual asm?)
|
|
- Zig-like try-based error handling where the V flag could indicate error condition? and/or BRK to jump into monitor on failure? (has to set BRK vector for that)
|
|
- add special (u)word array type (or modifier?) that puts the array into memory as 2 separate byte-arrays 1 for LSB 1 for MSB -> allows for word arrays of length 256 and faster indexing
|
|
- ast: don't rewrite by-reference parameter type to uword, but keep the original type (str, array)
|
|
BUT that makes the handling of these types different between the scope they are defined in, and the
|
|
scope they get passed in by reference... unless we make str and array types by-reference ALWAYS?
|
|
BUT that makes simple code accessing them in the declared scope very slow because that then has to always go through
|
|
the pointer rather than directly referencing the variable symbol in the generated asm....
|
|
Or maybe make codegen smart to check if it's a subroutine parameter or local declared variable?
|
|
|
|
|
|
Libraries:
|
|
|
|
- fix the problems in c128 target, and flesh out its libraries.
|
|
- fix the problems in atari target, and flesh out its libraries.
|
|
- c64: make the graphics.BITMAP_ADDRESS configurable (VIC banking)
|
|
- optimize several inner loops in gfx2 even further?
|
|
- add modes 3 and perhaps even 2 to gfx2 (16 color and 4 color)?
|
|
- add a flood fill routine to gfx2?
|
|
|
|
|
|
Expressions:
|
|
|
|
- rethink the whole "isAugmentable" business. Because the way this is determined, should always also be exactly mirrorred in the AugmentableAssignmentAsmGen or you'll get a crash at code gen time.
|
|
note: the new Ast doesn't need this any more so maybe we can get rid of it altogether in the old AST - but it's still used for something in the UnusedCodeRemover.
|
|
- can we get rid of pieces of asmgen.AssignmentAsmGen by just reusing the AugmentableAssignment ? generated code should not suffer
|
|
- rewrite expression tree evaluation such that it doesn't use an eval stack but flatten the tree into linear code that uses a fixed number of predetermined value 'variables'?
|
|
"Three address code" was mentioned. https://en.wikipedia.org/wiki/Three-address_code
|
|
these variables have to be unique for each subroutine because they could otherwise be interfered with from irq routines etc.
|
|
The VM IL solves this already (by using unlimited registers) but that still lacks a translation to 6502.
|
|
- this removes the need for the BinExprSplitter? (which is problematic and very limited now)
|
|
and perhaps the assignment splitting in BeforeAsmAstChanger too
|
|
|
|
Optimizations:
|
|
|
|
- various optimizers skip stuff if compTarget.name==VMTarget.NAME. When 6502-codegen is no longer done from
|
|
the old CompilerAst, those checks should probably be removed, or be made permanent
|
|
- VariableAllocator: can we think of a smarter strategy for allocating variables into zeropage, rather than first-come-first-served?
|
|
- when a loopvariable of a forloop isn't referenced in the body, and the iterations are known, replace the loop by a repeatloop
|
|
but we have no efficient way right now to see if the body references a variable.
|
|
|
|
|
|
STRUCTS again?
|
|
--------------
|
|
|
|
What if we were to re-introduce Structs in prog8? Some thoughts:
|
|
|
|
- can contain only numeric types (byte,word,float) - no nested structs, no reference types (strings, arrays) inside structs
|
|
- is just some syntactic sugar for a scoped set of variables -> ast transform to do exactly this before codegen. Codegen doesn't know about struct.
|
|
- no arrays of struct -- because too slow on 6502 to access those, rather use struct of arrays instead.
|
|
can we make this a compiler/codegen only issue? i.e. syntax is just as if it was an array of structs?
|
|
or make it explicit in the syntax so that it is clear what the memory layout of it is.
|
|
- ability to assign struct variable to another? this is slow but can be quite handy sometimes.
|
|
however how to handle this in a function that gets the struct passed as reference? Don't allow it there? (there's no pointer dereferencing concept in prog8)
|
|
- ability to be passed as argument to a function (by reference)?
|
|
however there is no typed pointer in prog8 at the moment so this can't be implemented in a meaningful way yet,
|
|
because there is no way to reference it as the struct type again. (current ast gets the by-reference parameter
|
|
type replaced by uword)
|
|
So-- maybe don't replace the parameter type in the ast? Should fix that for str and array types as well then
|
|
|