mirror of
https://github.com/irmen/prog8.git
synced 2024-11-27 03:50:27 +00:00
119 lines
8.2 KiB
ReStructuredText
119 lines
8.2 KiB
ReStructuredText
TODO
|
|
====
|
|
|
|
For next release
|
|
^^^^^^^^^^^^^^^^
|
|
- optimize pointervar indexing codegen: reading (expressions) via optimized codegen instead of @(pointer+idx)
|
|
- optimize pointervar indexing codegen: writing (all sorts of things)
|
|
- why is this code so much larger:
|
|
uword xx
|
|
for xx in 0 to size-1 {
|
|
gfx2.next_pixel(bitmapbuf[xx])
|
|
}
|
|
than this loop:
|
|
uword srcptr = bitmapbuf
|
|
repeat size {
|
|
gfx2.next_pixel(@(srcptr))
|
|
srcptr++
|
|
}
|
|
any difference between 6502 codegen and vm codegen?
|
|
|
|
- pipe operator: (targets other than 'Virtual'): allow non-unary function calls in the pipe that specify the other argument(s) in the calls. Already working for VM target.
|
|
- add McCarthy evaluation to shortcircuit and/or expressions. First do ifs by splitting them up? Then do expressions that compute a value?
|
|
- Inliner: also inline function call expressions, and remove it from the StatementOptimizer
|
|
...
|
|
|
|
|
|
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
|
|
- vm: somehow deal with asmsubs otherwise the vm IR can't fully encode all of prog8
|
|
- vm: don't store symbol names in instructions to make optimizing the IR easier? but what about jumps to labels. And it's no longer readable by humans.
|
|
- vm: how to remove all unused subroutines? (in the 6502 assembly codegen, we let 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
|
|
- 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.
|
|
- 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.
|
|
- simplifyConditionalExpression() should not split expression if it still results in stack-based evaluation, but how does it know?
|
|
- simplifyConditionalExpression() sometimes introduces needless assignment to r9 tempvar (what scenarios?)
|
|
- 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?
|
|
(but we lose the optimizing aspect of the assembler where it strips out unused code.
|
|
There's not really a dynamic switch possible as all assembly lib code is static and uses one or the other)
|
|
- 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....
|
|
|
|
|
|
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 2 and 3 to gfx2 (lowres 4 color and 16 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 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. Once (if?) 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
|
|
- translateUnaryFunctioncall() in BuiltinFunctionsAsmGen: should be able to assign parameters to a builtin function directly from register(s), this will make the use of a builtin function in a pipe expression more efficient without using a temporary variable
|
|
compare ``aa = startvalue(1) |> sin8u() |> cos8u() |> sin8u() |> cos8u()``
|
|
versus: ``aa = cos8u(sin8u(cos8u(sin8u(startvalue(1)))))`` the second one contains no sta cx16.r9L in between.
|
|
- AssignmentAsmGen.assignExpression() -> improve code gen for assigning boolean comparison expressions
|
|
Check what the vm target does here, maybe just do this as part of the vm -> 6502 codegen.
|
|
- when a for loop's loopvariable 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
|
|
- 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
|
|
|