mirror of
https://github.com/imjasonh/nescript
synced 2026-07-08 08:55:38 +00:00
fdb1ec7c91
Two correctness bugs were silently producing wrong ROMs:
- `x << n` / `x >> n` always shifted by 1, regardless of `n`, because
the IR lowering for `BinOp::ShiftLeft`/`ShiftRight` hardcoded the
count. Now eval_const the RHS into a compile-time count; fall back
to a new `IrOp::ShiftLeftVar` / `ShiftRightVar` (runtime loop) when
the amount isn't constant. Strength reduction folds the variable
form back to a fixed count once the optimizer knows the value.
- `x / n` / `x % n` always returned 0, because the lowering emitted
`LoadImm(t, 0)` for `BinOp::Div`/`Mod` with a comment saying the
runtime call was "TODO for now". Added real `IrOp::Div` and
`IrOp::Mod`, wired them through use-counting and DCE, gave codegen
`__divide`-based implementations, and taught strength reduction to
rewrite power-of-two divisors into shifts and modulo-by-2ⁿ into
AND masks. Constant folding now handles `Mul`/`Div`/`Mod`/shifts
too, which were previously left for the codegen to emit inefficient
software calls.
Dead code removed (no backward-compat shims kept):
- `src/debug/` entirely. `DebugSymbols`, `SourceMap`, and the
Mesen/.sym emitters had no callers outside their own tests;
`main.rs` never wrote a symbol file. Documented the intent in
`docs/future-work.md` so it comes back intentionally if needed.
- `ErrorCode::E0202` (invalid cast) and `E0403` (unreachable state):
defined, formatted, and marked `#[allow(dead_code)]` but never
emitted. W0104 now carries the unreachable-state semantics too.
- `Level::Info`: never constructed.
- `load_background` / `set_palette` statements and their
`BackgroundDecl` / `PaletteDecl` parser support: parsed and
silently dropped by IR lowering (`// TODO: implement in asset
pipeline`). Removed keywords, AST variants, parser paths, analyzer
arms, and tests. `docs/future-work.md` documents the runtime
palette/nametable design for when it comes back.
Doc cleanup:
- `docs/architecture.md` was describing files that don't exist
(`analyzer/types.rs`, `optimizer/const_fold.rs`, `codegen/regalloc.rs`,
`rom/header.rs`, `debug/symbols.rs`, …). Rewrote it to match the
real flat `mod.rs` + `tests.rs` layout and the real pipeline order.
- `docs/future-work.md` was a hybrid of open work and "recently
completed" entries that duplicated the active stubs at the top of
the file. Collapsed to just the gaps that are actually still open.
- `README.md` claimed Mesen symbol export and 210 tests; updated both.
- `docs/language-guide.md` and `spec.md` described `palette` decls,
`set_palette` / `load_background`, `debug.overlay`, and error codes
that were never emitted. Trimmed.
- Stale comments on `Statement::Play`/`StartMusic`/`StopMusic`
claimed the audio subsystem was "a no-op at codegen time".
Tests:
- Regression tests for every fix above (`lower_shift_left_with_literal
_count_uses_that_count`, `lower_shift_right_with_variable_count
_uses_runtime_variant`, `lower_divide_emits_div_op_not_load_imm
_zero`, `lower_modulo_emits_mod_op_not_load_imm_zero`,
`strength_reduce_div_by_power_of_two`, `strength_reduce_mod_by
_power_of_two`, `strength_reduce_shift_var_with_constant_amount`).
- Renamed the `program_with_sprites_and_palette` integration test
(which was exercising the now-removed `load_background`/`set_palette`)
to `program_with_inline_sprite_chr`.
`examples/sprites_and_palettes.ne` lost its `palette`/`set_palette`
usage. Nothing in the emulator test presses A, so the headless
jsnes render shouldn't move, but the golden may need regeneration
via `UPDATE_GOLDENS=1` if it does.
https://claude.ai/code/session_012fKB251HvEUQwG3tizFyqt
48 lines
1.1 KiB
Text
48 lines
1.1 KiB
Text
// Sprites and Scroll — demonstrates M3/M4 asset features.
|
|
//
|
|
// Shows: sprite declarations with inline CHR data, type casting,
|
|
// PPU scroll writes.
|
|
//
|
|
// Build: cargo run -- build examples/sprites_and_palettes.ne
|
|
|
|
game "Asset Demo" {
|
|
mapper: NROM
|
|
}
|
|
|
|
// Define a sprite with inline CHR tile data (16 bytes = one 8x8 tile)
|
|
// This is a simple arrow pointing right
|
|
sprite Arrow {
|
|
chr: [0x18, 0x1C, 0xFE, 0xFF, 0xFF, 0xFE, 0x1C, 0x18,
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
|
|
}
|
|
|
|
// Define a sprite with a heart shape
|
|
sprite Heart {
|
|
chr: [0x66, 0xFF, 0xFF, 0xFF, 0x7E, 0x3C, 0x18, 0x00,
|
|
0x66, 0xFF, 0xFF, 0xFF, 0x7E, 0x3C, 0x18, 0x00]
|
|
}
|
|
|
|
var px: u8 = 128
|
|
var py: u8 = 120
|
|
var scroll_x: u8 = 0
|
|
|
|
on frame {
|
|
// Movement
|
|
if button.right { px += 2 }
|
|
if button.left { px -= 2 }
|
|
if button.down { py += 2 }
|
|
if button.up { py -= 2 }
|
|
|
|
// Scroll background
|
|
scroll_x += 1
|
|
scroll(scroll_x, 0)
|
|
|
|
// Type cast demo
|
|
var wide: u16 = px as u16
|
|
|
|
// Draw sprites
|
|
draw Arrow at: (px, py)
|
|
draw Heart at: (px, py - 16)
|
|
}
|
|
|
|
start Main
|