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| author | Cliff Click <cliffc@acm.org> | 2026-09-25 15:28:21 -0700 |
|---|---|---|
| committer | Cliff Click <cliffc@acm.org> | 2026-09-25 15:28:21 -0700 |
| commit | 29e0127170dce8964d7f85d808d1ec07426d2789 (patch) | |
| tree | f9174685beaf274f3324a08c68f2b0a7137309c2 /docs | |
| parent | 12bde12b2e18c8b82b1510ac4305de66d1205e1a (diff) | |
| download | Simple-29e0127170dce8964d7f85d808d1ec07426d2789.tar.gz Simple-29e0127170dce8964d7f85d808d1ec07426d2789.zip | |
Restrict subtraction zero peepholes to integer operandspr254-fixes
Require resolved integer mode in chapter 25 so zero subtraction preserves floating-point signed zero. Keep nonnumeric operands in the graph for subtraction diagnostics.
Add signed-zero coverage from chapter 12 and null-subtraction diagnostics from chapter 22. Confirmed the regressions fail on the original PR. Full Make suites pass in chapters 4-25 (5462 tests), including fresh chapter 25 sys.o compilation.
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/chapter-backports.md | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/docs/chapter-backports.md b/docs/chapter-backports.md index 0f20d0b3..3cbd93c1 100644 --- a/docs/chapter-backports.md +++ b/docs/chapter-backports.md @@ -218,6 +218,7 @@ Unresolved reproductions have been promoted to the pending queue above. | Completed work | Scope and evidence retained | |---|---| +| #254 subtraction zero identities | Require integer operands in 4-25 and resolved integer mode in 25. Preserve floating-point signed zero and subtraction diagnostics. `Chapter12Test.testSubZeroFloat` runs in 12-25; `Chapter22Test.testSubZeroTypeError` runs in 22-25. Against the original PR, the signed-zero test fails in 25 and the diagnostic test fails in 22-25. Full Make suites passed in every chapter 4-25 on 2026-09-25, including fresh `sys.o` compilation in 25. | | Short type extrema | Memory, struct and memory-pointer BOT/TOP names from 10; function-pointer names from 18. Exact types use shortcuts in ordinary, nested and HTML prints; precise types retain their details. Full Make suites in 10-20 and type/frontend suites in 21-25 passed; canonical/nested print checks passed in 10-25. | | Integer result types | Integer-op fallbacks in 4-13 and remaining unary cases through 17 retain integer types; 5's Phis meet their data-input types. Full Make suites in 4-17 passed, plus a chapter 5 snapshot check of Phi/Add types. Integer BOT starts in 4; later arithmetic already has typed fallbacks, with unresolved bimorphic modes preserved in 25. | | B14 cyclic leaf-kind equality | 23-24 backport; 25 already correct. Cyclic equality starts in 23. `TypeTest.testCyclicLeafKinds` fails before the fix; earlier interned-child equality already checks kinds. Full affected suites passed. | |