Robert Allan JamesandClaude Sonnet 5
70db955ac9
mixed_math_word_m_slash_mod() had the identical bug class already fixed
in M* (commit 9a09949): it reconstructed the dividend from
`(dhigh << 32) | (dlow & 0xFFFFFFFF)`, the same wrong "32-bit halves of a
64-bit value" assumption. Latent for small inputs (fits in 32 bits, so the
reconstruction coincidentally worked), confirmed genuinely broken for a
true wide double -- feeding M*'s own correct 10^24 output into it gave a
quotient/remainder wrong by many orders of magnitude and the wrong sign.
Unlike M*, this one can't just switch to __int128 -- __int128's own `/`/`%`
need libgcc's __udivti3/__umodti3 for 128-bit division, unavailable in
this freestanding, -nostdlib build (the exact constraint
src/starkernel/arch/amd64/timer.c's own doc comment already flagged:
__int128 multiply/shift-by-constant/compare/subtract all compile clean,
only division doesn't). Fixed instead with a hand-rolled unsigned
128-by-64-bit bit-serial (restoring) long division -- 128 iterations of
shift-by-1/compare/subtract only, all in the safe set. Operates on
magnitudes via unsigned negation from 0 (well-defined even for the
extreme negative edge); signs reapplied afterward matching the same C99
truncating-toward-zero convention the previous, narrower implementation
already used, unchanged.
Verified: rebuilt all three architectures, confirmed clean link with no
__udivti3/__umodti3 undefined-symbol errors. Booted and tested all three,
identical results: 1000000000000 1000000000000 M* SWAP 1000000 M/MOD ->
1000000000000000000 remainder 0 (exact division, the case that was wrong
by orders of magnitude before); three sign-combination cases all correct
(-+, +-, --), confirming sign handling survived the magnitude-only
rewrite. T15 (original small-input case) unaffected. Full 24-case
exerciser reran clean on all three, no regressions.
All bugs found by the std79 exerciser campaign, including this one found
while fixing another, are now closed.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EXieurDfDSsDFdnSyusuWo
src/
Hosted StarForth VM implementation (compiled by the root Makefile).
Bare-metal kernel sources live in src/starkernel/; FORTH word
implementations in src/word_source/; the test harness in
src/test_runner/; platform shims in src/platform/.
Entry point / interpreter core
main.c— CLI entry point, VM init, DoE mode dispatch.vm.c— interpreter loop, stacks, dictionary state (the central runtime file).vm_api.c— external VM API implementation.vm_bootstrap.c— VM bootstrap initialization.vm_debug.c— debugging utilities.vm_time.c— time-related VM operations.vm_internal.h— internal-only declarations shared across thevm_*.cfiles, not part of the publicinclude/vm_api.hsurface.repl.c— REPL read-eval-print loop.cli.c— CLI argument parsing.io.c— I/O operations.log.c— logging infrastructure.
Memory / dictionary / blocks
memory_management.c— dictionary allocator.dictionary_management.c— dictionary allocation and search.dictionary_heat_optimization.c— Loop #1 execution-heat tracking.word_registry.c— word registration system.block_subsystem.c— logical→physical block mapper.blkio_file.c,blkio_ram.c,blkio_factory.c— block I/O backends (file-backed, RAM-backed) and the factory that selects between them.stack_management.c— stack operations.
Physics-driven adaptive runtime (7 feedback loops)
physics_runtime.c— main physics coordinator.physics_hotwords_cache.c— Loop #1 hot-words caching.physics_metadata.c— per-word metadata tracking.physics_pipelining_metrics.c— Loop #4 word-transition prediction.physics_execution_hooks.c— execution instrumentation.rolling_window_of_truth.c— Loop #2 circular execution-history buffer.inference_engine.c— Loops #5/#6, statistical inference (window-width, decay-slope).ssm_jacquard.c— L8 Jacquard steady-state mode selector; consumescompudynamics.cfor tuning-word/config lookups.compudynamics.c— generic compudynamics module (cd_tuning_word(),cd_tuning_vm()); the score/UCB/reward/weight constants for the L8 adaptive table live here, not inssm_jacquard.c.heartbeat_export.c— heartbeat metrics export (CSV export function itself not yet implemented — seedocs/working/architecture/heartbeat_csv_export.md).
Math / measurement
math_portable.c— portable math functions.profiler.c— performance profiling.doe_metrics.c— Design of Experiments metrics (2^7 factorial).
Any .bak file alongside a .c file here (doe_metrics.c.bak,
inference_engine.c.bak, vm.c.bak) is a pre-edit backup left by a past
maintenance script (see scripts/remove_loop_conditionals.sh), not a
build input.