Apple-2-SW/prog8
1
0
Fork 0
mirror of https://github.com/irmen/prog8.git synced 2025-01-12 19:29:50 +00:00
Code Issues Projects Releases Wiki Activity

todo

Browse Source
This commit is contained in:
Irmen de Jong 2023-03-15 00:52:37 +01:00
parent ff6948cf2d
commit b8113fff1e
1 changed files with 21 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
docs/source/todo.rst
View File

@ -3,6 +3,9 @@ TODO
For next minor release
^^^^^^^^^^^^^^^^^^^^^^
- when a loopvariable of a forloop is *only* referenced in the for loop as loopvariable, and the number of iterations is known, replace the loop by a repeatloop (and remove the vardecl)
but we have no efficient way right now to see if the body references a variable. (what about ReferencesIdentifier? - only on Expressions now)
...
@ -15,8 +18,8 @@ For 9.0 major changes
- Some more support for (64tass) SEGMENTS ?
- Add a mechanism to allocate variables into golden ram (or segments really) (see GoldenRam class)
- maybe treat block "golden" in a special way: can only contain vars, every var will be allocated in the Golden ram area?
- the variables can NOT have initialization values, they will all be set to zero on startup (simple memset)
just initialize them yourself in start() if you need a non-zero value
- maybe or may not needed: the variables can NOT have initialization values, they will all be set to zero on startup (simple memset)
just initialize them yourself in start() if you need a non-zero value .
- OR.... do all this automatically if 'golden' is enabled as a compiler option? So compiler allocates in ZP first, then Golden Ram, then regular ram
- OR.... make all this more generic and use some %segment option to create real segments for 64tass?
- (need separate step in codegen and IR to write the "golden" variables)
@ -33,24 +36,28 @@ Future Things and Ideas
^^^^^^^^^^^^^^^^^^^^^^^
Compiler:
- ir: can we determine for the loop variable in forloops if it could be kept in a (virtual) register instead of a real variable? Need to be able to check if the variable is used by another statement beside just the for loop.
- ir: mechanism to determine for chunks which registers are getting input values from "outside"
- ir: mechanism to determine for chunks which registers are passing values out? (i.e. are used again in another chunk)
- ir: peephole opt: renumber registers in chunks to start with 1 again every time (but keep entry values in mind!)
- ir: peephole opt: reuse registers in chunks (but keep result registers in mind that pass values out! and don't renumber registers above SyscallRegisterBase!)
- ir: add more optimizations in IRPeepholeOptimizer
- ir: for expressions with array indexes that occur multiple times, can we avoid loading them into new virtualregs everytime and just reuse a single virtualreg as indexer?
- vm: somehow be able to load a label address as value? (VmProgramLoader) this may require storing the program in actual memory bytes though...
- ir: for expressions with array indexes that occur multiple times, can we avoid loading them into new virtualregs everytime and just reuse a single virtualreg as indexer? (simple form of common subexpression elimination)
- PtAst/IR: more complex common subexpression eliminations
- vm: somehow be able to load a label address as value? (VmProgramLoader) this may require storing the program as bytecodes in actual memory though...
- 6502 codegen: see if we can let for loops skip the loop if startvar>endvar, without adding a lot of code size/duplicating the loop condition.
It is documented behavior to now loop 'around' $00 but it's too easy to forget about!
Lot of work because of so many special cases in ForLoopsAsmgen..... (vm codegen already behaves like this)
- ir: can we determine for the loop variable in forloops if it could be kept in a (virtual) register instead of a real variable? Need to be able to check if the variable is used by another statement beside just the for loop.
- generate WASM to eventually run prog8 on a browser canvas?
- generate WASM to eventually run prog8 on a browser canvas? Use binaryen toolkit or my binaryen kotlin library?
- can we get rid of pieces of asmgen.AssignmentAsmGen by just reusing the AugmentableAssignment ? generated code should not suffer
- [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?)
Once new codegen is written that is based on the IR, this point is moot anyway as that will have its own dead code removal.
- 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)
Perhaps replace all uses of .proc/.pend/.endproc by .block/.bend will fix that with a compiler flag?
But all library code written in asm uses .proc already..... (textual search/replace when writing the actual asm?)
Once new codegen is written that is based on the IR, this point is mostly moot anyway as that will have its own dead code removal on the IR level.
- 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) But the V flag is also set on certain normal instructions
- 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
this is an enormous amout of work, if this type is to be treated equally as existing (u)word , because all expression / lookup / assignment routines need to know about the distinction....
So maybe only allow the bare essntials? (store, get)
Libraries:
@ -65,8 +72,10 @@ Libraries:
Expressions:
- 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
- investigate if transforming BinaryExpression into RPN notation makes code generation better. (new Pt node: PtRpn that is just a list of PtOperators and PtExpression nodes, except PtBinaryExpression and PtRpn sub-nodes.)
It's super easy to determine the number of stack positions required for this RPN expression (even grouped per data type).
Which should make it easier to not use the eval stack for this, but a limited set of regular variables instead.
- Or rewrite expression tree evaluation such that it doesn't use an eval stack but flatten the tree into linear code
that, for instance, uses a fixed number of predetermined value 'variables'?
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)
@ -76,8 +85,6 @@ Optimizations:
- VariableAllocator: can we think of a smarter strategy for allocating variables into zeropage, rather than first-come-first-served?
for instance, vars used inside loops first, then loopvars, then the rest
- when a loopvariable of a forloop isn't referenced in the body, and the number of iterations is known, replace the loop by a repeatloop
but we have no efficient way right now to see if the body references a variable.
- various optimizers skip stuff if compTarget.name==VMTarget.NAME. Once 6502-codegen is done from IR code,
those checks should probably be removed, or be made permanent