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https://github.com/RetroPortingToolKit/psxrecomp
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Matthew Stanley
77e66f9da3
Codegen-side foundation for cycle-driven peripheral timing per
docs/CYCLE_TIMING_ARCH.md. Each emitted basic block now calls
psx_advance_cycles(N) where N is the conservative 1-cycle-per-MIPS-
instruction count for the block (sum from leader to next leader,
including delay slot).
Generic per-instruction emit, no card-specific paths. Macro-gated by
PSX_ENABLE_BLOCK_CYCLES so generated output is comparable on/off.
This slice does NOT wire psx_advance_cycles to peripheral advance.
Reason: sio_tick has a legacy IRQ-countdown body that decrements
unconditionally per call; calling it from psx_advance_cycles (which
fires per block, ~100M+ times/sec) drains that countdown in
microseconds and breaks pad timing. A future slice with a peripheral-
only sio_advance (no legacy side effect) will wire SIO. Card byte-15
abort persists for now — expected; the fix needs that peripheral wiring.
Files:
- recompiler/src/full_function_emitter.cpp:
- precompute block_cycles map (instr count between leaders)
- emit psx_advance_cycles(<N>u) under #ifdef PSX_ENABLE_BLOCK_CYCLES
at every block leader, before psx_check_interrupts
- emit extern decl in generated header
- generated/SCPH1001_full.c: regenerated; 12794 PSX_ENABLE_BLOCK_CYCLES
guards, one per block leader
- runtime/CMakeLists.txt: PSX_ENABLE_BLOCK_CYCLES=1 added to both
psx-runtime and psx-beetleoracle target_compile_definitions
- runtime/src/psx_cycles.c: psx_advance_cycles accumulates counter only;
peripheral dispatch deferred to next slice (rationale in comment)
Validation against 5d4d4bd baseline:
- Build clean both targets
- t=20s tx_writes=928, t=30s tx_writes=5000 (matches baseline)
- pad arm audit 5056/5056 armed, no_ack=0
- 4x CROSS press all succeed
- card txn distribution unchanged: txns reach READ_DATA, "MC" bytes
flow at txn 0 bytes 10-11 (0x4D 0x43)
- psx_cycle_count grows: 1.72B (t=20s), 2.33B (t=30s), 10.04B
post-CROSS — proves codegen emit live and per-block accounting works
- Macro=0 build (verified before macro flip): output identical to
baseline
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>