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diff --git a/src/test/java/com/seaofnodes/simple/spill/README.md b/src/test/java/com/seaofnodes/simple/spill/README.md new file mode 100644 index 00000000..b5ab9d80 --- /dev/null +++ b/src/test/java/com/seaofnodes/simple/spill/README.md @@ -0,0 +1,78 @@ +# Historical allocation cohorts + +English | [日本語](README.ja.md) + +`cohorts.tsv` freezes 199 compilation entries matching Chapter 24's +`SpillStats`: 39, 52, 26, 24, and 58 entries for cohorts 20-24. The source files +are deduplicated by contents and named for their first referring test. The +manifest preserves test identity, target, ABI, and the original stopping phase. +`Win64` becomes `win64`, the Chapter 25 ABI spelling. Argument type is i64 and +the replay seed is 123 throughout. + +The original 212 entries were captured from the Chapter 24 tests before the +allocator audit's new correctness regressions. The 2026-10-07 refresh adds +Chapter22Test.testNarrowCReturns on x86 SystemV and Win64, matching the two +entries already measured in Chapters 22-24. The source is unchanged; only the +manifest's ABI spelling changes. The [cross-chapter matrix](../../../../../../../../docs/regalloc-spills.md) +checks matching test/CPU/ABI membership, including repeated compilations. +The same refresh removes all 15 Jig entries: six from cohort 23 and nine from +cohort 24. Jig methods are ignored scratch pads for debugging, not regression +tests or allocation benchmarks. Their frozen source copies were removed too. +These inputs are a stable comparison corpus; changing one +requires explaining the resulting break in comparability. Synthetic allocator +and instruction regressions do not contribute allocations to these cohorts. + +Chapter 25 cannot parse all earlier sources unchanged. Adaptations are explicit: + +- String, Scan, and linked S constructors replace `new S { field=...; }` with + declared constructors and arguments. The explicit-receiver scanner functions + become instance methods, preserving their operations. +- The saved `Chapter21Test-testStringExport`, `Chapter21AllocTest-testString`, + and `Chapter23AllocTest-testString` sources declare + `new String = { u8[] data -> cs=data; };` to initialize the required non-null + `cs` field. This repairs ten replay entries (four, three, and three), without + changing their equality/hash bodies or manifest membership. These adapted + sources are a new comparison baseline; their totals cannot be compared as + identical inputs with the earlier constructor-free fixtures. +- The two short-circuit RHS initializer loops become equivalent guarded blocks, + preserving allocation, side effects, and the final result. Their RHS assigns + the field value directly: Simple's `||` returns an operand, not a normalized + boolean. The 2026-10-07 cleanup removes an erroneous `!!` in those adaptations; + both fixtures return 44 for even arguments and 1 for odd arguments. +- Simple I/O cases include the old `write` binding and print helper directly. + Bubble Sort includes the old library bodies, with namespace prefixes flattened, + explicit constructors, and mutable replacement buffers. This retains the old + workload instead of substituting Chapter 25's substantially revised example. +- Local implementation names are private in eleven fixtures: the four Newton + variants that call their helper from the top level, Chapter 20's MergeSort, + String and Cast programs, and Chapter 22's three sign-extension programs and + InfiniteReturn. Their helpers/classes acquire an underscore prefix; operations, + inputs and final results are unchanged. This avoids exporting implementation + functions and allocation factories solely because Chapter 25 treats top-level + declarations as module members. Export/API fixtures, including NewtonExport, + StringExport, Person and the C-return wrappers, retain their public names. + These visibility adaptations change the generated workload and are recorded + separately from the allocator improvement in the cross-chapter comparison. +- The remaining visibility cleanup makes local classes/functions private in + AntiDeps1, Infinite, the Chapter 21/23 allocation String cases, the Chapter 23 + scanner/pointer/short-circuit/function cases, and Stack3/Stack5. Bubble Sort's + copied library implementation is private; its `main` stays public. The three + adapted String API fixtures end in `return 0;`, avoiding an accidental return + of the last declared function. Their equality/hash APIs stay public, and the + named StringExport fixture also keeps its public String factory. No cohort + entries, workload operations, or intentional export APIs are removed. +- Other source texts are retained. + +All entries replay **through RegAlloc**, checking scheduled register constraints. +The historical phase column is provenance, not a promise to run those old native +harnesses in Chapter 25. The adapted Bubble Sort retains its historical +`i32 errno="C"` declaration for allocation comparability. Direct data bindings +now encode on all three targets, but this declaration cannot link to a libc +whose errno is thread-local or accessor-based. Current system-library code uses +`libc.errno()` instead. Do not count this corpus as historical runtime coverage. + +`SpillStats` then compiles the current system library through encoding at seed +456, and runs Chapter25Test with its existing seeds and native checks. Together +these form cohort 25. A library or test failure makes the report fail; partial +totals cannot establish an improvement. The ordinary full chapter suite remains +the execution validation for the current compiler. |