mirror of
https://github.com/imjasonh/nescript
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0de1d60c33
Drop the three-instruction JOY2 shift block (`LDA $4017 / LSR A / ROL ZP_INPUT_P2`) from inside the NMI's 8-iteration input loop when user code never reads controller 2. IR codegen emits the `__p2_input_used` marker from `IrOp::ReadInput(_, 1)`; the linker threads the flag through a new `NmiOptions::has_p2_input` bool, and `gen_nmi` writes the shift block only when the flag is set. Savings for single-player programs: - ~6 bytes of NMI code. - ~30 cycles per frame (3 instructions × 8 loop iterations, each 6-8 cycles depending on addressing — LDA abs is 4, LSR A is 2, ROL zp is 5, so ~11 cycles × 8 = ~88 cycles; rounded down for the page-crossing penalty landing differently in the new layout). This commit also fixes the IR codegen to drop the matching `__p1_input_used` marker from `IrOp::ReadInput(_, 0)`, even though the next commit is the one that actually consumes it. Landing the two markers together keeps the IR codegen's per-op bookkeeping coherent. Six audio goldens flip (every program that reads input + plays audio) with the expected NMI-layout-shift cycle drift. https://claude.ai/code/session_016kM6P7PukktBDqTZexrrAN |
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| .. | ||
| analyzer | ||
| asm | ||
| assets | ||
| codegen | ||
| errors | ||
| ir | ||
| lexer | ||
| linker | ||
| optimizer | ||
| parser | ||
| rom | ||
| runtime | ||
| lib.rs | ||
| main.rs | ||
| pipeline.rs | ||